Author Archives: Elena Motivans

About Elena Motivans

I've always liked the way that words can sound together. Combined with my love for nature (and biology background), I'm interested in diving deep into different topics- in the natural world even the most mundane is fascinating!

The unusual origins of our favorite spices

As we cook, we bring the world into our kitchens with the different spices that we use. Though we use spices regularly and think about how they change the flavor of our dishes, we don’t typically considered their origins. Many commonly used spices, such as thyme, basil, and oregano, come from plant leaves, but there are more exotic spices that have become commonplace in our kitchens that are grown in pretty interesting ways.

Image credits: pikrepo.

Here are some commonly used spices with interesting background stories:

Cinnamon

Cinnamon is a warming spice that we often associate with wintertime and holiday baking. It comes from the inner bark of cinnamon trees (genus Cinnamomum). Cinnamon trees are evergreen and have oval leaves, thick bark, and produce little round berries. The tree looks unsuspecting from the outside, but under the layers of outer bark lies the cinnamon layer. Although there are multiple species of cinnamon tree, only five are grown commercially, and they each have slightly different textures and aromas. Your cinnamon likely comes from China or Indonesia: they produced 75% of cinnamon sold globally in 2016. Cinnamon gets its distinctive smell and taste from its main essential oil, cinnamaldehyde, as well as other components.

A cinnamon tree. Image credits: Afifa Afrin.

The harvesting of cinnamon is a lengthy process. After the seed is planted, a cinnamon tree grows for about two years before it is »coppiced«, a fancy word meaning it is chopped to a stump. This coerces the plant to grow more as a bush. The following year about a dozen new shoots will grow out of the side of the stump. These shoots are then cut and they need to be processed quickly while the inner bark is still wet. The outer bark is scraped off and then the inner bark is loosened with a hammer and then detached in meter-long strips. These strips are dried out over a period of four to six hours. While drying they curl up. They are then cut into small pieces to become the cinnamon sticks that we recognize and enjoy using to flavor hot drinks, or later ground to be used in baking.

Black pepper

Where would we be without salt and pepper? Although pepper is now a basic spice in many cuisines, it has an exotic origin. It is native to southern and southeastern Asia but grows well in tropical regions. Vietnam is the largest pepper producer, growing 34%of pepper sold worldwide in 2013. Black pepper (Piper nigrum) is a flowering vine that produces round, red fruit called peppercorns. Most common pepper types come from the same plant but are prepared differently: black pepper comes from the cooked and dried unripe fruit, green pepper comes from the dried unripe fruit, and white pepper comes from the ripe fruit seeds. Pepper’s spiciness comes from the chemical compound piperine, making it different from chili peppers, which are spicy due to capsaicin.

Black pepper growing on a vine. Image credits: Royjose.

The woody vines grow up to 4 meters (13 feet) long so they are grown on supports. It takes the plant about four or five years to start producing fruit, and typically continues to do so for about seven years. One stem grows twenty to thirty fruit clusters. The harvesters know that it is time to harvest when one or two fruits at the base of the cluster start to turn red. If the harvesters are too late and the fruit ripens, they lose their pungency and fall off the plant. The clusters are cut and sun-dried before the individual peppercorns are removed. Black pepper is processed by briefly cooking the unripe peppercorns in water. The heat from cooking causes cell walls to burst and speeds up the browning process in the subsequent drying stage. After a few days of drying, the peppercorns have their characteristic appearance with thin, wrinkly, black skin.

Vanilla

Vanilla ice-cream, cakes, frosting, sugar… the subtle aroma of vanilla is extremely popular in baking and prepared food. Surely, you have seen pictures of vanilla flowers on food packaging, but did you know that it is an orchid? The plant originates from mesoamerica, but it is now grown globally. Vanilla pods are the fruit of the flower and are filled with an oily liquid and small seeds. Madagascar and Indonesia produce two-thirds of the world’s vanilla. The Mexican species Vanilla planifolia, otherwise known as flat-leaved vanilla, is predominantly grown for this beloved flavoring. There are two other vanilla species that are also commercially grown: V. Pompona and V. Tahitensis. The typical smell and taste of natural vanilla is very complex and comprised of hundreds of different compounds, including vanillin, acetaldehyde, and acetic acid. Synthetic vanilla is usually made from synthetically produced vanillin in ethanol.

Fresh vanilla flowers. Image credits: Malcolm Manners.

True vanilla is the second-most expensive spice because it takes a lot of effort to produce it. It grows as a vine and therefore needs support in order to grow. It needs to be pollinated by specific bee species or hummingbirds to produce a fruit. However, these pollinators only naturally reside in Mexico. Therefore, the flowers need to be pollinated by hand, which is very laborious. The harvest is also labor intensive, as each fruit ripens at its own pace, necessitating harvesters to check the plants daily. It is difficult to judge when the pod is ripe, but the current standard is to pick each pod by hand as it starts to split on one end. Then the vanilla needs to be cured before it can be sold. There are several methods for this process, but all of them involve the same basic steps: killing, sweating, slow-drying, and conditioning the vanilla beans.

Saffron

Saffron is not such a common household spice due to its price. It is, after all, the most expensive spice in the world at 5,000 USD per kg. The red threads are from the stigma and styles (the female part) of the saffron crocus (Crocus sativus). The saffron that you buy most likely comes from Iran, as it produces 90% of the world’s saffron. Its taste and fragrance come from the phytochemicals picrocrocin and safranal. The carotenoid pigment, crocin, causes food spiced with saffron to have a golden color. You can know if the saffron that you buy is fresh if it is bright crimson, slightly moist, and clear of broken-off threads.

The saffron crocus with its distinctive crimson stigmas and styles. Image credits: Serpico.

The saffron crocus produces vegetatively through underground bulbs. This means that workers need to dig up these bulbs at the end of the season, divide them up, and replant them so they grow into new plants the next season. The plants grow rather late in the year and only flower mid-autumn. It is necessary to be super speedy in harvesting the saffron as the plants blossom at daybreak and wilt within the same day. The stigmas are dried as soon as they are removed. It is not surprising that saffron is so expensive when you think of how much work is involved. For one kilogram of saffron, 200,000 stigmas need to be handpicked from 70,000 flowers.

Cloves

Like cinnamon, cloves come to mind as a wintertime spice, perfect for mulled wine and as a touch of spice in cookies. Cloves are unopened flower buds from a tree, Syzygium aromaticum, that is native to Indonesia. The clove aroma comes from the essential oil eugenol, which is also commercially extracted from cloves. This essential oil is often used for personal hygiene products like toothpaste, soaps, and perfumes due to its antiseptic and anesthetic properties.

When these buds are dried they become the aromatic herb. Image credits: Steenbergs.

The clove tree is a tropic evergreen that grows 8-12 meters (26-39 feet) tall with large leaves and crimson flowers. The tree has to grow for at least six years before flowering to allow cloves to be harvested. The flower buds are pale and turn green and then red over the period of five to six months. When they turn red, they are ready for harvest. 1.5-2 centimeters (0.59-0.79 inches) are carefully snipped off the tip of the branch and dried for 4-5 days until they lose two thirds of their weight. As the buds dry, they turn brown and their main essential oil, eugenol, becomes more concentrated. Then they are ready for sale.

Cumin

Cumin adds an aromatic dimension to savory dishes. It is actually a seed from a flowering plant in the parsley family, Cuminum cyminum. If you’ve planted parsley in your garden, perhaps you’ve noticed the similarity between the seeds. It is native to south western Asia and currently China and India produce 70% of the world’s cumin and eat 90% of it. If you buy commercial birdseed, you will probably find cumin in the mix. It has been used as a spice for thousands of years; ancient Egyptians used it to spice food and preserve the dead and ancient Greeks loved it so much that they kept a »cumin shaker« on their dining tables.

The cumin plant. Image credits: Herbolario Allium.

The cumin plant is pretty hardy and resistant to drought. It likes hot temperatures and can be grown in the tropics or subtropics. The plants grow up to 0.3 m (1 ft) tall with thin and feathery leaves and small white flowers. The flowers don’t last long before developing into clusters of cumin seeds. The seeds are ready for harvest when they turn brown and then they are dried. It takes a long hot summer for a good cumin harvest.

Many of the spices that we enjoy in our cooking and baking are pretty laborious to produce! We can appreciate that more next time we crack some fresh black pepper or enjoy vanilla cake.

Of mammoth proportions: the difference between mammoths and mastodons

If you’ve ever visited a natural history museum, you might have seen a grand skeleton tower over you, with giant tusks gently sloping to the sky and a shape reminiscent of an elephant. Perhaps you thought immediately of a woolly mammoth, the most famous elephant relative, popularized by Manny, the grumpy mammoth in Ice Age. However, there is another relative that you most certainly have also heard of: the mastodon.

Although similar, there are key differences between mammoths and mastodons.

An impressive mammoth skeleton. Image credits: Kelley Minars.

Origin of mastodons and mammoth

First of all, mastodons came into existence much earlier, about 27 to 30 million years ago. Mammoths are “young” by comparison, having emerged a mere 5.1 million years ago in Africa. There were multiple mammoth species, but the famous woolly mammoth is the baby of the bunch, emerging only 250,000-400,000 years ago.

Mammoths could be found across Eurasia and North America. Mastodons were not so widespread and called North and Central America their home (still a considerable area considering that they could be found from Alaska to central Mexico).

Although mammoths preferred cooler temperatures and mastodons preferred warmer temperatures, they both lived in Beringia, the land between East Siberia and Alaska that wasn’t covered by ocean during the Ice Ages.

They lived there at the same time during the early to mid-Pleistocene, but the mastodons left because it got too chilly for them. Mammoths still survived in Beringia until 13,000 years ago, and a subset that evolved to be small (about the size of a large horse) survived on arctic islands until as recently as 4,000 years ago.

To put it into perspective, the Great Pyramid was being constructed around the same time mini mammoths were ruling an arctic island — as crazy as it sounds, mammoths and the pyramids were around around at the same time (for a brief period).

Lifestyle differences

Mammoths and mastodons led different lifestyles and their appearance reflects these differences.

Mastodons lived mainly in forests. Accordingly, their teeth have cone-shaped cusps, perfect for crushing leaves and twigs. Sometimes, the plants that animals eat are also preserved alongside their fossil remains. Researchers who have quantified mastodon gut contents have found a lot of twigs from coniferous trees, while another study found mostly low, herbaceous vegetation in their guts. Therefore, they likely browsed and grazed, changing their preference based on the season and where they were.

A mastodon depicted in its forest habitat. Image credits: Heinrich Harder (1858-1935).

Mastodons were named for the shape of their teeth. The French taxonomist Georges Cuvier apparently thought that the teeth looked like breasts so he derived their name from masto (“breast” in Greek) and odon (“teeth” in Greek).

Mastodon teeth. Image credits: Jstuby.

On the other hand, mammoths are much more closely related to modern-day elephants than mastodons, and lived a similar lifestyle. They also used to live on large, open plains and had flat teeth with ridges for grazing. Elephants also have similarly shaped teeth. Mammoths mostly ate flowering plants because they contain more protein and are easier to digest than grasses. Some species of mammoth also munched on other types of vegetarian fare, such as cactus leaves, trees, and shrubs.

A baby mammoth preserved in the permafrost also brought to the light that baby mammoths ate their parents’ dung because it is easier to chew, like elephants living today do.

Mammoth tooth. Image credits: James St. John.

Physical differences between mammoths and mastodons

Though mammoths and mastodons were both large, hairy, elephant-like creatures, they did have some differences other than their tooth shape. Mastodons were a bit shorter and stockier. Since mammoths tended to live in colder climates, they had fatty humps where they stored extra nutrients necessary to survive the long, frigid winters and warmer fur coat. Mammoth tusks curved more while mastodon tusks were straighter and shorter.

Mammoths had a distinctive bump at the top of their skulls while mastodons had flatter heads. There were multiple species of mammoth (not just the woolly mammoth!) and mastodon that varied slightly in different aspects of their appearance — skeletal and dental differences, for example.

A face-to-face comparison of the mammoth (left) and mastodon (right). Image credits: Dantheman9758.

Extinction

Although mastodons evolved earlier than mammoths, both went extinct at a similar time, about 10,000 years ago.

There is some disagreement between experts about what exactly brought about the demise of these gentle giants — but there are two prevailing theories.

The first is that they were unable to survive due to increasing temperatures after the end of the last ice age 12,000 years ago. Glaciers retreated and sea levels rose, with the warmer temperature causing the environment to change. Forests grew up where open woodland and grasslands had been. The arctic tundra and steppe were dominated by flowering plants, but when the climate became wetter and warmer, they were replaced by grasses, which were not so nutritious or easy to digest for mammoths.

However, some researchers argue that similar warming periods had occurred over the past several million years within the ice age without such disastrous consequences. Therefore, the second theory is that someone new on the scene played a large role in their demise, more specifically, humans.

There is evidence that Homo erectus ate mammoth meat 1.8 million years ago, but this could be a result of scavenging as opposed to active hunting.

Some sites created in the past 50,000 years in Eastern Europe and Britain present further evidence that humans hunted mammoths: dwellings made from mammoth bones and mammoth remains. The spread of more skilled human hunters around Eurasia and North America coincided with the disappearance of mammoths and mastodons. However, these creatures lived across such an enormous area, including remote areas of Siberia, that it is uncertain if humans with primitive weapons would have been able to decimate them.

Did humans hunted the mammoth to extinction? Image credits:
http://cloudinary.com.

It is more likely that the combination of a changing climate and human hunters led these giants to their end. The shrinking of suitable areas to live likely caused many to die out, rendering the remaining populations more vulnerable.

All in all, mammoths and mastodons lived different lifestyles, but still looked quite similar, except for some special adaptations for their diet and climate. They also share similar causes for their demise. Now, on your next visit to the natural history museum, see if you can guess if that big, tusked skeleton is a mammoth or mastodon.

It’s time to rediscover the forgotten crops of the world

If you go to different grocery stores around the world, you will probably see similar offerings: potatoes, salad, tomatoes, bananas, and oranges in the produce section and wheat flour, rice, beans, and corn meal on the shelves. However, the plant products that you see for sale are just a tiny fraction of those that exist! 

Image credits: Pxfuel.

In total, there are 1,097 vegetable species cultivated around the world, but we’ve only heard about 7% of them. The vegetables that we know about are being researched more and bred to be high-yielding; they are reaching other markets around the world due to globalization. However, we shouldn’t forget about all of the other edible plants out there. Many of the plants that have been traditionally grown are very nutritious and can grow in tough conditions. The impediment is that they haven’t been researched so well and don’t have a large demand. Therefore, they are called “neglected” or “forgotten” species in that they are largely ignored by research and are not used to their potential in local and global food markets. Many local varieties have already gone extinct: 75% of the species that humans have grown before 1900 are already gone. These species should not be overlooked as they could be an important piece in figuring out the puzzle of global food security. 

Quinoa: a forgotten plant success story. Image credits: blairingmedia.

Some neglected species have already entered the mainstream market and could be available at your local supermarket, such as quinoa, buckwheat, jackfruit, seabuckthorn, and amaranth. While these plants are starting to become hip, usually for health benefits or because they are trendy, there are many that you probably haven’t heard about.

Here are just a few neglected plants that have superfood potential and deserve more attention:

Fonio 

Fonio (Digitaria exilis), the millet species with the smallest seeds, is a cereal that is traditionally grown in West Africa. For being a small seed, it sure can boast a lot: it is nutritious, gluten-free, and high in dietary fiber. It is one of the fastest growing cereals, taking only six to eight weeks to grow to maturity. It is used in a variety of different ways, from porridge, to couscous, bread, and even beer. It grows best in dry climates, and can even grow in poor soils, making it an ideal crop for arid regions. 

Fonio. Image credits: Communication JOKKALE.

The only down-side to this cereal powerhouse is that it takes a lot of effort to harvest and process. The plants are cut down by sickle and gathered in bundles to dry. The grains are threshed off the plant manually and then washed by hand. Because the grains are so small, it is difficult and takes a lot of time to get rid of the husk. They are traditionally ground in a bowl with sand, and then the grains need to be separated from the sand with water. Luckily, a machine has been invented to de-husk fonio, reducing the amount of time to process two kilograms of fonio from one hour to six minutes. It could be coming to markets besides Africa. An Italian company, Obà Food, has gotten permission to start selling fonio in the European Union. 

Harvesting fonio. Image credits: James Courtright.

Ullucus 

The Ullucus tuber (Ullucus tuberosus) is grown in South America and is the second most important root vegetable grown in the Andes, just after the potato. This vegetable has been grown by small-scale farmers high in the mountains (2500 to 4000 m above sea level) for centuries. The tubers provide a good source of protein, carbohydrates, and vitamin C. The tubers are strikingly colored, such as yellow, pink, and purple. The tubers are typically cooked into a soup or stew, pickled, or ground into a flour. Due to their high water content, they do not lend themselves to frying or baking, but when cooked, they retain a crisp texture.  In addition to the tuber, the leaves of the tuber are a protein, calcium, and carotene-packed, spinach-like green.

Ullucus tubers. Image credits: Eric Hunt.

Carob

The carob (Ceratonia siliqua) is a flowering tree that grows in a Mediterranean climate in Europe, the Middle East, and Africa. It is in the legume family and produces edible pods that are dark brown and elongated. The pods need a whole year to ripen and fall in the early autumn.

Ripe carob pods. Image credits: Chixoy.

When the pods are ripe, they can be dried and ground in a powder. The powder’s taste is compared to cocoa powder, though carob powder is naturally sweet and is caffeine-free. The powder can be used as cocoa powder, as a bar, chips, and in baking. Carob bars and other products are often found at health food stores. The trees are resilient and can survive long droughts, though they do need 250 to 500 mm of rainfall per year to grow fruit. They can also survive exposure to salt in the soil and rainfall.  

Jujube

Jujube is a small tree with thorny branches that grows in Asia and the Middle East (Ziziphus jujuba). It produces a small, oval fruit, about 1.5 to 3 centimeters long. Before it is ripe, its surface is smooth and green and it tastes like an apple. However, when it is ripe it matures to a deep brown or purple-black color with wrinkly skin similar to a date. At its center is a hard kernel that looks like an olive pit and contains two seeds. 

Some ripe and ripening jujubes. Image credits:
Jacqueline Gabardy.

The tree is hardy and can survive across different temperatures and amounts of rainfall, though it needs hot summers and enough water to produce fruit. Because it can also survive cold winters (all the way down to −15 °C (5 °F)!), it can be grown both in mountain or desert areas. The fruit is eaten as a snack both fresh and dried. Additionally, the tree is cultivated in China and is used in Chinese and Korean traditional medicine, where they are used for a number of purposes, including contraception, stress relief, wound healing, and sedation. 

Purslane

Purslane (Portulaca oleracea) is a plant that is eaten in Europe, the Middle East, Asia, and Mexico. It grows close to the ground and has smooth, red-tinged stems and leaves. It is able to survive through drought and in poor compacted soils. The whole plant, stems, leaves, and flower buds are all edible. It tastes mildly sour and salty. It can be eaten raw in salads or sautéed and used in soups and stews. The sour taste is due to the presence of oxalic and malic acid, the concentrations of which are the highest when the plant is picked in the morning. 

Purslane. Image credits: Júlio Reis.

Many of these plants have some important features in common: they can survive through tough environmental conditions, are nutritious, and have been traditionally grown for food. These features make them ideal to promote food security. They deserve more recognition and shouldn’t be neglected in favor of the plant species that are heavily researched and grown all around the world. Let’s keep all the amazing diversity of edible plants that humans have been cultivating for millennia!

Pollination 101: the basics on what it is and why it matters

Pollination has been in the news a lot recently: pollinators are dying out due to pesticides, diseases, and not being able to find enough food. This is a big problem for many crops and wild plants because many depend on pollinators in order to reproduce. Read on for the steamy details on pollination and how it supports the existence of our crops and wild plants.

What is pollination

Flowers have both male and female parts. The male part is made up of the anthers, which are supported by filaments. The anthers are important because they produce pollen. The female part is made up of a sticky stigma that is connected to an ovary with eggs inside. In order to make seeds, the pollen from the anthers needs to reach the stigma. However, there is a little problem. Plants need their pollen to reach another flower of the same species, but they cannot move. There are two solutions to this problem. The first is that wind can carry the pollen to another flower. The second is that pollinators carry pollen from one flower to another. This method is more efficient for flowers and therefore is used by most wild plants. Flowers want to attract pollinators so they produce sweet nectar at the base of their petals.

The parts a flower. Image credits: ProFlowers.

Pollinators do not know that plants want them to carry their pollen around. They are more concerned with getting food for themselves and their offspring. Nectar contains sugar and nutrients, which can give pollinators lots of energy, and pollen contains protein. Many pollinators have hairs, fur, or feathers. As they drink nectar or collect pollen, they rub against pollen from the anthers, which sticks on their fuzzy bodies. As they move on to the next flower, some of the pollen already on their bodies get stuck on the sticky stigma. The pollinators don’t even know that they are helping the plants out. Once pollen attaches to the stigma, it germinates. Pollen tubes form and stretch down until they reach the ovary. When they touch the egg, they fertilize it and form a seed. The seeds mature and when they are ready, they are released. These seeds grow up to be new plants.

A fly pollinator being an unwitting pollen carrier. Image credits: Forest Wander.

Our tasty food depends on pollination!

5-8 % of global crop production is completely dependent on pollinators. However, this is not the whole picture, as many more crops are tastier, produce higher yields, or improved in some other way by pollination. Of the most used crops, 75% depend on pollination to some degree. For example, tomatoes that are pollinated by insects are bigger and taste better. If pollinators were to disappear, food production would be very strongly affected. Do you like chocolate? It depends on a single type of fly to pollinate it, if it were to go extinct, we’d be in trouble! Many other commodities that we enjoy also depend on pollination, such as coffee, almond milk, and exotic fruits.

Did you know that different fruits and vegetables depend on pollinators in different ways?

Veggies

Curcurbits such as squash, zucchini, pumpkins, melons and watermelons need pollinators. They have separate male and female flowers and need pollinators to transfer pollen from the male flowers to the female flowers. If this does not occur, there aren’t any vegetables.

Squash have male (above) and female (below) flowers. In the female flower, you can see well that the ovary is what will turn into the squash. Image credits: Abrahami.

Soloanaceae such as tomatoes, bell peppers, eggplants, and chili peppers can have male and female parts in the same flower so they are able to self-pollinate but have a higher yield, taste better and are bigger when insect pollinated. They have a special type of anther that needs to be vibrated at a particular frequency to release pollen. Insects such as bumblebees and other types of solitary bees buzz at this frequency and can effectively pollinate these plants.

There are vegetables that are not the fruits of pollination and do not explicitly require pollinators for their production, but need them to produce seeds. For example, roots like potatoes, carrots and onions; flowers like broccoli, leaves like salad, and herbs like thyme, basil, oregano, rosemary are not formed from a plant ovary. However, they do produce flowers that need to be pollinated to produce seeds and therefore for new plants to grow.

Rice flowers.. not so impressive. Image credits: Pixabay.

Some crops like corn, wheat, rice, barley, rye, and oats rely on wind pollination and do not need any insect pollination at all. These are dietary staples so at least their production would be stable in the absence of pollinators. These plants produce billions of pollen grains and only a few of them will reach the female parts of other plants and produce seeds. Some nuts such as walnuts, pistachios, and hazelnuts are wind pollinated. As they don’t need to attract pollinators, they have very small, plain flowers.

Fruits

Some plants are self-incompatible. This means that they need pollen from a different variety. For example, a Gala apple cannot be pollinated by the pollen from another Gala apple. It needs pollen from another cultivar to produce a fruit, though some apple varieties are able to still produce some fruit without pollinators. For this reason, orchards also have crabapples or different types of cultivars that produce a lot of pollen so the apple flowers receive the pollen they need to develop into a fruit. Other examples of crops dependent on pollination are pears and almonds.

Most apples need pollen from another cultivar to produce a fruit. Image credits: PxHere.

There are also fruits and berries that are self-compatible and can produce fruit without pollinators. They do require pollinators to increase the yield and quality of the fruit. For example, a raspberry flower is made up of 100-125 female parts. Each little segment of a raspberry is actually a tiny fruit, so at least 80 of these little fruits need to form to have a normal raspberry. If there are fewer segments, the raspberry falls apart or isn’t so juicy. Pollinators help spread pollen to more stigmas to make sure you have a nice, juicy raspberry. Cherries, peaches, strawberries, and plums are all self-fertile.

Most wild plants need pollinators

Pollinators aren’t just important for making sure that we have enough food to eat, they are important for all of the flowers in our gardens, in meadows, and everywhere else in nature! 90% of wild plants are insect pollinated. Many plant species are completely dependent on pollinators, while others produce more, better quality seeds when they are pollinated. Therefore, wild plants depend on insects so that they can produce new seeds and that new flowers can grow. Not to mention that many insects and other animals depend on plants for food. Some insect larvae, like caterpillars, depend on a single type of plant while they are growing up. For example, monarch caterpillars need milkweed. If they can’t find milkweed, then they don’t survive to make their impressive migration.

We do not know how a loss of pollinators would actually affect the world’s plants. Researchers can only guess what the world would be like without pollinators by looking at places in the world where lots of pollinators have already gone extinct and by performing experiments.

Hawaiian honeycreepers, endangered but important pollinators. Image credits: Gregory “Slobirdr” Smith.

Hawaii is a place where many pollinators have gone extinct so we can look at the effects. Many flowers were pollinated by birds found only on the archipelago. One-third of 52 bird species in Hawaii have gone extinct and many others are so rare that they are not able to pollinate so many flowers. Plants native to Hawaii have thin, curved flowers specially adapted for bird pollination. Due to the loss of their pollinators, 31 of these plant species have gone extinct in the last century. Many other large groups of pollinators have gone extinct, including 52 endemic bee species in the same genus and 26 moth species. The common house plant, Hawaii palm (Brighamia insignis), otherwise known as cabbage on a stick, is possibly extinct in the wild due to the extinction of its only pollinator, a hawkmoth. Although there are many other problems, such as habitat loss and introduction of invasive species and diseases, the loss of pollinators is a major contributing factor to about half of the 1200 native plant species in Hawaii being at risk of extinction. Some plants on Hawaii are now pollinated by invasive birds or mammals, but many are left without pollinators. Hawaii is an extreme case because it has many species found only there that have specialized relationships. In this case, the loss of pollinators can have a big effect.

Wildflowers need pollinators! Image credits: Needpix.

Researchers in Europe have also conducted some experiments to see what a meadow would look like with fewer pollinators. They engineered covers that they placed over parts of meadows so that fewer pollinators would visit those plants. After a four year period, they found out that pollinators are responsible for keeping meadows full of different flower species and producing more new plants. The sections with fewer pollinators had fewer new flowers growing and the ones that did grow weren’t represented by very many different species.

All in all, we have pollinators to thank for a smorgasbord of colorful, tasty food, not to mention the flowers that ornament our balconies, parks, and wild habitats, giving us something nice to look at and giving many animals the food and space that they need.

Animals take medicine when they are sick: a few striking cases

Humans are not the only ones to use medicine to treat diseases. There’s even a science dedicated to animal self-medication: zoopharmacognosy, from the roots zoo (“animal”), pharma (“drug”), and gnosis (“knowing”). Who knew?

Humans have been medicating using plants for thousands of years — but we’re not the only ones.

Our understanding of animals using medication has shifted over time. One of the earliest researchers in zoopharmacognosy established criteria for defining when an animal is using medicine.

The plant should not be a regular part of the animal’s diet, have no nutritional value, be consumed in time of the year when parasites are more active, and should only be used by a single animal at a time. These criteria are the most relevant with primates, which actively choose medication when they are sick (presumably, a similar practice was employed by early humans).

In addition to active learning, some animals learn innately (such as through natural selection), such as insects and other invertebrates with tiny brains.  Other types of medicine use in animals are recognized, such as giving medicine to family members and using the same substance as usual but in higher quantities.

Here are some interesting cases of animals that use medicine when they are sick:

Primates

As they are our closest relatives, it is probably isn’t surprising that primates use medicine. At around the same time that Jane Goodall was observing chimpanzees in Tanzania in the 1960s, so was a Japanese anthropologist called Toshisada Nishida. He saw chimpanzees eating aspella leaves, which he found a bit strange as they don’t have any nutritional value for the chimps.

Likewise, at Jane’s Gombe reserve and other locations, chimpanzees were seen swallowing whole leaves. The researchers hypothesized that they were using the leaves as medication. Additional support came many years later in 1996, when the biologist Michael Huffman saw a sick chimp ridden with parasites that chewed on leaves of a noxious plant and recovered by the next day. Other researchers have observed bonobos take leaves that cause itchy skin and layer many of them on their tongues, carefully avoiding touching their skin. They use saliva to stick a whole ball of leaves together that they then swallow whole. The reason that they layer the leaves is so that it becomes a sort of time-release medication that acts over a longer period of time.

A bonobo eating bamboo leaves. It turns to special, rough leaves when parasite-ridden. Image credits: Tambako The Jaguar.

In general, the primates seem to swallow these rough leaves to scrape the parasites out of their intestines and speed up elimination. They wouldn’t normally eat these leaves because they are prickly, noxious, and without nutritional value. A long time ago, a primate ancestor probably happened to grab a leaf when s/he was sick, and felt better afterwards. Then others picked up the behavior from the first discoverer.

Monarch butterflies

Not all animals actively learn to take medicine like primates. In most cases, the animals learn innately and a behavior is promoted through natural selection. The iconic monarch butterfly depends on the milkweed plant as its caterpillars exclusively eat it.

There’s a special type of anti-parasitic milkweed and only infected butterflies lay their eggs on it; healthy butterflies don’t look twice at it. However, by laying their eggs on it, infected butterflies ensure that their offspring are protected from infection. It is hard to say how consciously they are making this decision, but it does seem to be an innate behavior. Perhaps the parasite changes the physiology of the monarch butterfly and how she perceives the vegetation around her changes; she could genetically prefer beneficial plants in her parasite-ridden state. If the medication works then her offspring survive and can pass the behavior on to the next generation. In other words, the use of medicine could undergo natural selection. It doesn’t require a conscious choice of a medicinal compound like a human or primate would do.

Monarch on milkweed. Image credits: USFWS Midwest Region.

Other insects also take medication against parasites like the woolly bear caterpillar, which ingests plants that are toxic to parasites, and fruit flies, which lay their eggs in the alcohol from fermented fruit to keep parasitic wasps away from their offspring.

Birds

Some birds have started stuffing an unlikely material into their nests: cigarette butts. No, they’re not ne’er-do-well parents. On the contrary, they could actually be using the chemicals in the butts as medicine against parasitic mites, protecting their little chicks. It’s not as crazy as it seems as tobacco leaves contain chemicals that repel pests; tobacco juice and nicotine sprays can be used as garden pest control.

A bird with a cigarette. Image credits: Tony Wills.

Researchers studied two bird species that are common in North America, house sparrows and house finches, and measured the amount of cellulose acetate, a synthetic fiber found in cigarette butts, present in their nests. They found that nests with higher levels of this fiber contained fewer parasitic mites. Additionally, the researchers placed unsmoked and smoked cigarette butts in bird nests and found that there were half as many parasites in the nests with smoked cigarettes than non-smoked cigarettes. Smoked cigarettes contain much more nicotine because the smoke has passed through them.

Therefore, the researchers have a hunch that nicotine could be what the birds are using as medicine against a mite infestation in their nests.

Bees

Honey bees often collect resins produced by plants and stick them onto their hive. In particular, they use resins as medication after a fungal infection. After being affected by harmful fungus, such as chalkbrood, the bees collect more resin than they do normally. As a test to see if increased amounts of resins can protect against fungal infections, researchers added resins to experimental bee colonies. The result: colonies with more resin had fewer fungal infections. Therefore, the resin is an effective type of medication.

A fungal disease affecting a bee colony. Although it is hard to tell as the image is from a beekeeping book from 1900, dead larva of different ages can be seen in the cells. Image credits: Internet Archive Book Images.

This case of animal self-medication is particularly interesting because the medicine doesn’t act on a single individual but rather on the whole colony. The whole colony assesses the need for more resin after an infection and allocates workers for the task. The resin is also not individually ingested but has positive effects for everyone. This finding has implications for bee-keeping as beekeepers usually choose tidier bees and not those that cover their hives in annoying, sticky resin. However, by selecting for “cleaner” hives, the overall health of the bees may be reduced as they do not self-medicate after fungal infections.

There are many, many other cases of animals self-medicating. A few other colorful cases are lizards that eat a particular root after being bitten by a venomous snake, baboons with flatworms that cause schistosomiasis eat the leaves from a particular plant to get rid of those nasty parasites, and pregnant elephants in Kenya that eat tree leaves to induce delivery. As you can see, there is a wide spectrum of animals using medicine, and surely, there are more cases that we do not know about yet!

Understanding how animals use medicine can influence how we manage animals like honeybees and model diseases in wildlife populations. Some animals have been known to use plants that combat a lot of human diseases, and some medicine has been created from them that are in use for humans. Learning from animals has influenced traditional medicine and may still help us to find compounds that are powerful against certain diseases.

The hard difference between horns and antlers

Some animals sport some truly impressive headgear, from antlers the size of a small tree to robust horns. However, though they are similar, there are important differences between horns and antlers in how they are formed and of what they are made.

Antlers

Antlers are found exclusively in the Cervidae family, which is made up of deer and their relatives. Male deer have two small, bony structures on top of their heads that are called pedicles. The antlers grow out of the pedicles. Antlers are made of bone and are coated in “velvet”, a thin fuzzy layer of skin and blood vessels. Velvet supplies oxygen and blood to the antlers as they grow. When the antlers have grown to their full size, the velvet dies off. Each year, the deer shed their antlers and grow a new pair. Yes, it’s true; those crazy antlers grow in just one season!

A bull elk growing a new set of antlers covered in velvet. Image credits: Yellowstone National Park.

Antlers are mainly used to attract females and to fight against other males over leadership. Indeed, sexual selection is the main reason for their evolution, through direct male competition for females, as a symbol of dominance, and through female selection. Males with larger antlers are considered fitter because of their position as alpha males. Additionally, antlers are indicators of good metabolic efficiency and food gathering, desirable traits for a future reproductive partner.

However, antlers are not just used in acquiring a mate. They are used for protection against predators, such as wolves. Wolves are more likely to attack and kill male elk without antlers that those with them.

Antlers also have a special function for moose. Basically, they act like giant hearing aids. Apparently, moose with antlers can hear better than those without them.

A male and female reindeer. Image credits: Walter Baxter.

Reindeer use their antlers to clear away snow to eat plants hiding underneath. For this reason, both males and females grow antlers, though the females’ antlers are smaller. It is the only species where both the sexes have antlers. Males shed their antlers before winter, while females keep their antlers through winter, possibly because they compete with other females during winter foraging.

Horns

In contrast to antlers, horns are kept for life; they are never shed. Members of the family Bovidae (cows, goats, antelopes etc) grow horns. Horns have a full bone core and are covered in keratin, the same substance that makes up human fingernails. Horns usually have a curved or spiral shape with ridges. They start to grow soon after the animal is born and grow across the animal’s whole lifetime. If they are damaged or removed, they do not re-grow.

A goat with true horns. Image credits: Pixabay.

Males and females can both have horns though it is more usual for males. The theory is that larger species living in the open, like large herbivores in the savannah, are more visible to predators. Therefore, both males and females both usually have horns to defend themselves.

Horns typically grow in symmetrical pairs. Usually, animals only have one set of horns but there are some interesting sheep breeds that possess multiple sets of horns, such as the Hebridean, Islandic and Navajo-Churro breeds.

Sheep with two sets of horns. Image credits: Cathy Cassie.

Animals use horns primarily for defending themselves from predators, and even fighting members of their own species for territory, dominance, or a mate. They can also be used for functional purposes, such as digging in the soil or stripping bark from trees. Horns might even work as a cooling system for animals, with the blood vessels in the bony core of the horn letting off heat.

Other

Though horns and antlers are the most common cranial appendages, there are some other types. Giraffes and okapis have little bony growths called ossicones. The ossicones start out as cartilage growth and then eventually harden so that by the time the animal reaches puberty, the growths have hardened into bone and fused to the skull. They are usually covered in skin and fur, though the tips of ossicones in okapis sometimes have bare tips.

Pronghorns also have a special type of headgear that mixes characteristics typical of both horns and antlers. They are like horns in that the core is bone with a keratin covering, but they branch out and get shed annually like antlers.

A pronghorn. Image credits: Tobias Klenze.

Though they are valuable, rhino “horns” are actually not true horns. They are entirely formed out of keratin and do not have a bone core as horns do. They can also grow back after if a stump is left. Apparently, if a rhino’s horn is regularly trimmed every 18 months, a rhino will grow 130 pounds (59 kg) of horn over its full life span.

The hard truth is that horns and antlers have a similar function, though antlers are perhaps a greater metabolic feat as they are grown every single year from scratch. They are both composed of bone, but horns also have a keratin covering. Here’s to some truly impressive cranial appendages!

How horizontal gene transfer complicated the tree of life

All of life can be ordered into a tree, with branches separating and growing out as new species arise and become extinct, only the longest branches extending in the current day. It is an attractive image, promoted, of course, by Lamarck and Darwin, but it is not as simple as it appears.

As we know, genes are passed down from parents to their offspring, but there are some rare events where genes are passed between unrelated individuals. This phenomenon is called horizontal or lateral gene transfer. It is estimated that 5-6% of the bacterial genome is derived from horizontal transfer and that its role in multi-celled organisms is also being uncovered. It complicates our traditional idea of nicely ordered trees by adding lines between branches. It may seem like it may just be used for jaded scientists who study evolution but it has direct implications on humans, more particularly, for human health.

The tree of life. Image credits: Ernst Haeckel from the The Evolution of Man .

Ways genes can be transferred horizontally

There are three ways that genes can be passed between unrelated individuals; these are conjugation, transformation, and transduction.

(1) Conjugation passes genetic material via cell-to-cell contact, often through plasmids, which are circular units of DNA that are able to replicate on their own. The cells can inject these plasmids into other cells.

(2) Transformation involves bacteria incorporating DNA directly from their environment, such as from dead cells that have split open and released their genetic contents.

(3) Transduction occurs when a virus, in particular a bacteriophage, transfers DNA from one cell to another. Bacteriophages are unable to replicate on their own so they override the bacterial replication machinery in a host cell, making it replicate the virus instead until the cell is so full of virus particles that it ruptures. These new phages are then released into the environment to infect more hosts. Some phages alternate between infecting hosts and lysogeny, where they combine their genome with the bacterial chromosome and go inactive for multiple generations. When they take themselves out of the bacterial chromosome, they sometimes take some pieces of bacterial DNA with them.

How horizontal gene transfer can occur. Image credits: 2013MMG320B.

Consequences on…

Okay, so organisms can transfer genes to other organisms but how does that matter? Horizontal transfer has huge consequences, in particular, for the virulence of bacteria, helpful adaptations for other organisms, human cancers, and how we study evolution.

Bacterial resistance

Since bacteria can share and incorporate foreign DNA so easily, this process has played an important role in their evolution. Unfortunately for us, this makes them extremely adaptable and a ferocious opponent. One huge problem that humans are facing is the development of bacterial resistance to our antibiotics. The reason that antibiotic resistance can spread so easily is that one bacterium can evolve the resistance and then pass it on to unrelated bacteria through the previously mentioned mechanisms. It can also cause other adaptations that are good for bacteria but bad for humans, including evolving the ability to degrade compounds such as pesticides.

The bacteria in the right Petri dish has developed resistance to antibiotics. Image credits:
Dr Graham Beards.

Human health

Horizontal gene transfer is not just limited to single celled organisms. There has been even more evidence of this process in multicellular organisms as well. A recent study including 40 genomes from different types of animals found that they had genes transferred from bacteria and fungi, some relatively recently. These sequences may still be functionally within their new hosts. The results supported other studies that found that human genes, like FTO, the fat mass and obesity-associated gene, may have been horizontally transferred.

In some cases, horizontal gene transfer can cause human cancers. The human papillomavirus (HPV) can integrate itself into cervical cells and if they are not completed integrated, some proteins become unregulated causing the cells to proliferate unbounded, causing cancer. The hepatitis B virus behaves in a similar way for hepatocellular cancer. A researcher at the University of Georgia has found bacterial integrations in 36 genes in gastric samples with cancer. It is unclear though if it is a side effect or cause of cancer. In addition to cancer, horizontal gene transfer has helped out pathogens that invade humans. Bites from assassin bugs can infect humans with trypanosomal Chagas disease, which can insert its DNA directly into the human genome. The malaria pathogen has acquired some human DNA, which could help it to stay longer in the body.

The course of evolution

There are many cases of transferred genes that can be useful to their host and help the host to evolve to their environment. There are too many to go into detail here but I will highlight a few. The coffee berry borer beetle is the most notorious pest for coffee production. The gene that allows the pest to eat coffee berries is a mannanase gene that comes from bacteria. The invasive mamorated stink bug might also have a similar gene from bacteria which helps to cause major crop damage.

A bdelloid rotifer. Image credits: Danelle Vivier.

To our current knowledge, bdelloid rotifers are the animals with the highest amount of horizontal gene transfer; 8% of their genes come from bacteria. Not all genes horizontally transferred come from bacteria, hornworts gave the ferns a gene for surviving in dark forests about 180 millions years ago. An agrobacterium gave plants genes that causes cells to proliferate as roots and crown galls.

The study of evolution

The discovery of horizontal gene transfer has complicated the way that scientists figure out how related species are to each other. In the past, some relationships were shown based on the sequencing of a single gene. If two distantly related species have exchanged that gene, the phylogenetic tree will portray them as very closely related although most of their other genes and evolutionary history are very different. The most common gene for constructing phylogenetic relationships has been the 16S ribosomal RNA gene, as it is often conserved among closely related species. However, recent research has shown that this gene can also be horizontally transferred.

An illustration of horizontal gene transfer’s affect on the tree of life. Image credits: Barth F. Smets, Ph.D.

Now, it is best practice to use a wide range of different genes to infer phylogenetic relationships between species to avoid this problem. Bacterial genomes have been more sequenced than eukaryote genomes because they are smaller so there has been a bias. What we know about horizontal gene transfer and its prevalence will likely increase as genomic databases expand.

Horizontal gene transfer might have flipped what we know about evolution on its head, but it gives us new insight into how life is interconnected.

40% of the world’s plant species are extremely rare

The earth harbors a wealth of plant species. However, scientists have found out that 40% of them are very rare and at risk due to climate change and human activity.

A group of 35 researchers, including the lead author Brian Enquist, Professor of Ecology and Evolutionary Biology at the University of Arizona, spent ten years putting together the most comprehensive database of plant occurrences, the integrated Botanical Information and Ecology Network (BIEN), with more than 200 million observations. In total, they recorded about 435,000 different plant species, the highest number of plant species ever recorded.

“That’s an important number to have, but it’s also just bookkeeping. What we really wanted to understand is the nature of that diversity and what will happen to this diversity in the future,” Enquist said. “Some species are found everywhere – they’re like the Starbucks of plant species. But others are very rare – think a small standalone café.”

In total, 36.5% of all plants were very rare, meaning that they were observed five times or fewer. The researchers controlled for sampling and taxonomic bias and found that the results still held. It turns out that rarity is common for plants.

A map of the hot spots of plant rarity. Image credits: Patrick R. Roehrdanz.

There are certain regions in the world that are hot spots for rare plant species, such as the Northern Andes in South America, Costa Rica, South Africa, Madagascar and Southeast Asia. These regions support such a high diversity of rare species because they have had a stable climate for a long period of time.

However, due to climate change, these once-stable climates are now changing as rapidly as the rest of the world. Therefore, many of these species are expected to go extinct. In particular, the southern Andes and Southeast Asia are predicted to experience the largest decreases. Not to mention that these regions will face high human impact in terms of habitat destruction.

“We learned that in many of these regions, there’s increasing human activity such as agriculture, cities and towns, land use and clearing. So that’s not exactly the best of news,” Enquist said. “If nothing is done, this all indicates that there will be a significant reduction in diversity – mainly in rare species – because their low numbers make them more prone to extinction.”

Now that we know more definitively where the rarest plants in the world reside, we can plan strategically how to protect them.

Reference: Enquist et al. The commonness of rarity: Global and future distribution of rarity across land plants. Science Advances 27 Nov 2019 : eaaz0414.

How cytoplasm keeps your cells up and running

Cytoplasm sounds like some sort of goop that aliens spray out, but it is actually something more commonplace and important. It is all the material within a cell besides the cell nucleus and plays crucial roles in the cell.

Composition of cytoplasm

It is composed of three key parts: the cytosol, organelles, and cytoplasmic inclusions.

The cytosol makes up the vast majority of a cell, about 70% of its total volume. It comprises everything that is inside the cell except what can be found within the organelles. Think of it like a tiny soup with noodles (cytosketelon filaments that give the cell structure), broth (dissolved molecules), and water (actually water). There are also some bonuses in the mix including ribosomes (that create proteins) and proteasomes (that degrade unneeded or damaged proteins).

Organelles, as the name suggests, are like little organs found within a cell, each with their own function to carry out that allows the cell to function as a whole. The major organelles in cells are the ones that we all learn about in high school biology: mitochondria, the endoplasmic reticulum, the Golgi apparatus, vacuoles, lysosomes, and chloroplasts in plant cells.

Cytoplasmic inclusions are substances that do not dissolve in cytoplasm. For example, starch and glycogen granules store energy within the cell. Lipid droplets are storage spheres for fatty acids and sterols.

An animal cell. Image credits: OpenStax Anatomy and Physiology.

Functions

  1. The cytoplasm is crucial for keeping the cell in shape, without it, the cell would be like a deflated balloon and the organelles wouldn’t stay suspended. The cytoskeleton filaments give the cells shape, while the semi-liquid quality of the cytoplasm keeps everything in place, but also allows the various parts of the cell to move around and perform their functions.
  2. It also performs essential processes such as cell respiration and cell division.
  3. The ribosomes and proteasomes take care of all of the protein synthesis and destruction.
  4. Enzymes making up the cytoplasm break down waste and help with metabolic activity.
  5. The cytoplasm plays an active role in moving nutrients in and out of the cell.

Disagreement

One aspect of the cytoplasm that is still unknown is what the physical nature of the cytoplasm is. It is often jelly-like and smaller particles travel faster through it than larger particles. A researcher in 1923 postulated that the cytoplasm acts like a sol-gel, meaning that it goes through some phases of being a more liquid solution and a some of being a solid gel. Through tracking single cytoplasm components, researchers have recently proposed that cytoplasm acts like a glass-forming liquid approaching the glass transition. The higher the concentration of elements in the cytoplasm, the more it behaves like a solid. Further, researchers measuring cytoplasm with force spectrum microscopy found that it acts like an elastic solid.

Regardless of the disagreement, we know that cytoplasm provides the backbone for all the functions in the cell.

Like a pair of lovebirds: how birds court and mate

Do you have any guess as to what percentage of bird species have penises?

The answer is quite shocking. In total, only 3% of them have penises. The majority of bird species have lost them over the course of evolution. You may wonder then how birds manage to have sex. As it turns out, they do it through a combination of courtship rituals and having a special organ in lieu of a penis.

The courtship ritual

To find an attractive and fit mate, birds often have quite elaborate courtship rituals. Males usually need to attract the female who has the final say on the matter. Most scientists believe that the main reason behind their rituals is for the female to choose a desirable male with whom she can produce healthy offspring. However, there are other scientists who believe that females don’t always care about what makes a male fit but choose males with characteristics that they find beautiful (there is a really nice RadioLab podcast on this topic).

There are actually many different types of courtship rituals. The main types are singing, displays, dancing, preening, feeding, and building. Some birds use a mixture of multiple behaviors to attract a female.

Singing

Singing is the most common courtship behavior, as you may have noticed in the springtime. In birds, such as song sparrows, the song complexity or repertoire can show that a male would be a desirable partner. In other birds, other types of song might be favored. Male white bellbirds have recently been found to have the loudest call of any animal, although they are only the size of a dove. They are particularly loud when females are close and swivel to direct the sound at them. So apparently female bellbirds have a taste for loud males.

White bellbird calls are the loudest in the world. Credit: Anselmo d’Affonseca, Instituto Nacional de Pesquisas da Amazonia.

Ornamentation

Having fancy feathers or other body features can also be a desirable trait. The most famous example is, of course, the peacock with its flamboyant plumage. Some birds adopt special positions or postures to show their plumage to the best effect, such as puffing out, hunching their shoulders, or flaring their wings.

Dancing

Another common mating habit is the courtship dance. Many different types of movement can make up a courtship dances, and there are lots of different dancing styles out there. Usually, the male performs for the female, but occasionally they engage and dance together. A female looks for a good dancer, and would be harsh against any mistakes as these could show inexperience or weakness. My favorite example is the bird of paradise which splays out its wing to form a fan and hops around the female. The red-capped manakin also does a little moonwalk-type deal on a tree branch.

The “mooonwalking” red-capped manakin. Image credits: Nat Geo WILD.

Building

Males sometimes also build nests or mating structures to show off their building skills and ability to defend a good nesting site. For example, male bowerbirds create bowers, structures composed out of wooden sticks. Even after creating these impressive structures, they are not finished. They decorate their bowers with brightly colored or attractive objects, like shells, flowers, berries, or even bits of garbage. On top of this, the males present courtship displays to the females, who may visit several bowers before making a final decision.

A satin bowerbird waiting for a female to visit his bower. Image credits: Joseph C Boone.

The mating process

Birds (both male and female) have cloacas instead of other sexual organs. The cloaca (interestingly, Latin for “sewer”) is an internal chamber where urine, feces, and sperm are released. It ends in an opening where these substances are then discharged. When it’s mating season, the cloacal openings of birds swell up. Once a male bird has been given the okay by the female, he usually perches on top of her, and she moves her tail feathers aside for better access. The male rubs his cloaca against the female’s and at this moment the sperm is released and deposited in the female’s cloaca where it goes on to fertilize an egg. You may blink and miss it though; mating is very quick and usually lasts less than a second.

Toucans mating. Image credits: Brian Ralphs.

However, as mentioned in the beginning, a few birds do still have penises. These are mostly aquatic birds, as a penis enables the birds to copulate in water. A cloaca could be risky in the water because the sperm could get washed away without entering the female. The penis is different than that of a mammal and constructed as an extension of the cloacal wall. It is erected by lymph rather than blood. And some ducks take it to the extreme. Though there is variation among species, some ducks, such as ruddy drakes, have penises that are even longer than their own bodies. Other birds, such as cassowaries, kiwis, and ostriches, also have penises although they live on land. They do still have quick sexual encounters.

All in all, birds have some very strange and elaborate courting behavior, which culminates in very time-efficient mating.

The slimy difference between toads and frogs

Can you tell the difference between a frog and a toad? You might think that it’s easy, toads are warty and frogs have smooth, slimy skin. However, it’s not always as straightforward as it seems.

In general, there are some key differences between toads and frogs that make it possible to distinguish between them quite easily. If you’ve seen a frog, it’s probably been in or near a pond, while you’re more likely to encounter toads in drier areas. Toads crawl, have bumpy skin, and usually lay their eggs in large strands. Frogs jump around, have smooth skin, and lay their eggs in clumps. There are a few more physical differences that aren’t possible to spot so easily: toads have poison glands behind their eyes, distinctive chest cartilage, and lack teeth.

A typical frog and toad. Image credits: Thomas Brown.

What we consider toads are the “true toads”, which are part of a single family, Bufonidae, made up of 600 species. Most of them have the typical traits that we expect in toads. However, there are over 7,000 species of toads and frogs in the world and it can easily get quite confusing to know what is a frog and what is a toad. They have similar features because they both make up the order Anura in the animal kingdom. Toads actually make up one group of frogs, so all toads are frogs, but not all frogs are toads.

The TOAD Atelopus certus. Image credits: Brian Gratwicke.

Not all frogs and toads look or behave how we expect them. Some frogs look like toads with plain, bumpy skin, and some toads have smooth, brightly coloured skin. For example, the Harlequin Toads (genus Atelopus) are “true toads”, but you might think that they are frogs on first glance, because they are coloured in rich jewel shades and have smooth skin. They are often called frogs.

On the other hand, there are also frogs that get lumped in as “toads” just because they don’t adhere to typical frog beauty standards. This means that they could be drab-looking, have bumpy skin, and live more on land than near water. Indeed, hundreds of frogs from many different families, such as the Australian ground frogs (Myobatrachidae), fire-belly toads (Bombinatoridae), and the Asian toads (Megophryidae), get called toads although they are not.

The FROG Bombina variegata. Image credits: Miltos Gikas.

It can get confusing because the names “frog” and “toad” are used interchangeably in the common names for amphibians. For example, Bombina bombina is a frog but its common names include European fire-bellied toad, ringing frog, fiery toad, and fire frog. Therefore, some frogs are called toads although they are not, just because they look similar. The reverse also occurs, as Harlequin toads are often called Harlequin frogs. However, the easiest way to know is to look at the scientific family. If its in Bufonidae, it’s a “true toad”.

All in all, “true toads” are the only official toads and can usually be distinguished by their appearance. However, there are also some froggy toads and toady frogs.

Like a moth to the flame: why moths are attracted to light

In the summer, if you keep your light on and window open you are almost guaranteed to get some fluttering visitors. Moths, in particular, are notorious for being attracted to light, but what lures them in? Surprisingly, the exact reason as to why moths are attracted to light has not been definitively answered and there are not a lot of hard facts. However, there are a number of theories as to why moths are “drawn to the flame”.

Guided by the moon

The most prominent theory is that of transverse orientation. In simpler words, the moths may keep a fixed angle with the moon and the stars to orient themselves so that they fly in a straight line. This is a similar technique to humans using the North Star to navigate. However, this strategy only works when the light source is very far away. An artificial light seems brighter than the moon and could be mistaken for it. However, it is not far enough away to navigate by, which results in a spiral towards the light as the moth tries to keep a constant reference to it.

While light from the moon and stars is seen parallel by insects, light from a lamp radiates all around — and this can cause some obvious problems. First and foremost, moths will find themselves circling the light source in endless loops as they attempt to follow the light on one hand, while feeling the need to escape wind plume disturbances, on the other hand.

Because most flying animals tend to keep the lit sky above them so they don’t fly upside down, lamp-attracted insects will tend to dip down when closing in on an artificial light source that they may confuse with the skylight. This propensity is exploited by moth traps, which are designed to be placed around lamps at just the right distance to catch spiraling moths and send them down a collecting funnel into the trap.

Moths evolved when the strongest lights were emitted by celestial bodies so it could make sense that they don’t know how to deal with artificial light. However, it has not been proven that moths actually use transverse orientation to navigate, and if they did it would probably be just the migratory species using it, not the vast majority of small moths.

Researchers use light cones to attract moths in order to study them. Image credits: Bernard Dupont.

Sexy flames

In the 1970s, the entomologist Philip Callahan, who worked for the U.S. Department of Agriculture, discovered that lit candles emit an infrared light spectrum that is the same frequency as a female moth pheromone (he also discovered that these pheromones glow). So basically, the male moths would think that the flame is a female and die trying to mate with the flame. However, moths are even more attracted to UV than infrared light so this theory would not adequately explain the attraction to light — UV light does not have the same frequency as moth pheromones.

Glowing nectar

However, flower nectar does reflect UV light, and the moths’ visual system allows them to see in the UV range. Since many moths feed on nectar during the night, perhaps they are attracted to light because it could reveal a meal? Alas, moths use other ways to find food, such as detecting high levels of CO2 from the flower that can inform a moth about the presence of nectar in a flower.

In contrast

A final theory is that moths are confused because they actually want to reach the darkest point next to the light. The reason for this is that contrast makes a color difference look the sharpest due to “Mach bands”. So, next to a bright light, the dark spot nearby looks even darker. Dr. Henry Hsiao published in 1973 that moths in his experiments did not spiral into or fly directly at a light source, but instead flew into the region next to the lamps. It could be that they see a darker area next to the lamp due to the high contrast and fly there to try to escape the light.

Mach bands, as perceived by the human eye. Image credits: DancingPhilosopher.

Once they have reached a light, the moths might stay close to it for two reasons. Firstly, they may have tired themselves out and need to rest. Secondly, the brightness of the light might spark them to respond as they do to sunlight, which is to hide or become inactive.

Although we don’t know very much about why moths are attracted to light, we do know how far this attraction works. If you have a light on your porch on, you will attract moths that are up to 23 meters away. At least that is what Franz Hölker and his research group discovered in their experiments in one of Germany’s darkest areas in Westhavelland (known as an international “dark sky reserve”, also a haven for stargazers), 70 kilometers north west from Berlin. They found light to act like a vacuum cleaner in bringing all the moths in this radius to the light.

Artificial lighting can cause moths, and other insects, to waste time and energy. This can be particularly problematic for migrating species, for which timing is of the utmost importance. It can also lead to the insect’s death, by exhausting its energy reserves, being killed by humans, or by the heat of the light source.

Somehow light confuses moths, though it is unclear exactly why. Most of the research on this matter is older, and new technology would surely help to shed light on this question. Hopefully, researchers will renew this interest in this question to help settle it once and for all.

The EU should not import Brazilian products linked to deforestation and human rights violations, urges open letter from European scientists

Brazil is the custodian of rain forests that are crucial for protecting biodiversity and climate stability, in addition to being the home of almost one million indigenous people. However, the current government is putting both in danger at the expense of agricultural expansion. We are not just innocent onlookers as the EU has imported a third of crops and livestock associated with deforestation from 1990-2008. In order to show the EU that we want to put the environment and human rights first in trade agreements, more than 600 European scientists and 300 Brazilian Indigenous groups have come together to sign an open letter, that has been published today in Science.

A hidden price

Of course, we enjoy our beef, coffee, and palm oil, but they come at a heavy price. We may not think of where the products that we use come from, but the EU’s imported products have led to a loss in forest cover the size of Portugal in fewer than 20 years (1990-2008). Studies have shown that EU imports have led to the loss of 9.9 ha (roughly the size of a football field) of rain forest per hour from 2005 to 2013. Our personal diets can also be linked directly to tropical deforestation, up to a sixth of our diet-based carbon footprint.

“We want the EU to stop importing deforestation and instead become a world leader in sustainable trade,” said lead author Dr. Laura Kehoe, an Irish postdoctoral fellow at the University of Oxford who studies how meat consumption can drive deforestation, “we protect forests and human rights at home, why do we have different rules for our imports?”

Rain forest is being converted for pastures and crops. Image credits: Thiago Foresti.

It is important to stop cutting down rain forest for both environmental and humanitarian reasons. Brazil has an extremely high number of species that are only found there (second in the world after Indonesia). There are estimated to be 1.8 million species in the country, only 170,000 to 210,000 of which are currently known. All of this known and unknown diversity is at risk of going extinct if too much of the rain forest is cut down. The rain forest also sequesters carbon dioxide, and thus are an important buffer against global warming. Deforestation releases large volumes of CO2 from slashing and burning, as well as the replacement of forests with agriculture and ranches. Not only that, but removing forests can even disrupt climate patterns and lead to drought, threatening food security in Brazil. The indigenous groups that inhabit the forests and lead traditional lifestyles are under threat of losing their homes. The conversion of indigenous land has been linked to violence, with three attacks and at least nine casualties this year.

The path forward

“The irony is that there is really no need for further deforestation in Brazil: foreseeable agricultural demand could be met entirely from improving existing farm practices and restoring degraded land, without any more conversion of natural habitats”, added Andrew Balmford, Professor of Conservation Science at the University of Cambridge.

According to a recent study, there is actually no need to cut down more rain forest. By increasing the productivity of current pasture lands from 32-34% to 49-52% of their potential, they would be able to meet increased agricultural demands. It is estimated that restoring degraded lands and improving yields could meet demand for at least two decades, without additional deforestation.

Let’s protect the forests! Image credits: Larissa Rodrigues.

“It is crucial the EU defines criteria for sustainable trade with key stakeholders including the most affected parties, which in this case is local communities and indigenous groups in Brazil” said Malika Virah-Sawmy, a German resident and scientist at the Geography Department of Humboldt-Universität zu Berlin.

In the open letter, the signatories urge the EU to make trade with Brazil contingent on three key points. Firstly, Brazil should uphold the United Nations Declaration on the Rights of Indigenous Peoples. Secondly, the transparency of where goods come from should be improved. Consumers should be able to know if the products that they buy are associated with deforestation and Indigenous rights conflicts. Thirdly, Indigenous Peoples and local communities, including scientists and policy-makers, should be involved in defining social and environmental criteria for traded goods. If these three points are upheld, conditions will be better for the environment and for human rights.

As indirect players in the deforestation of rain forests, it should be the responsibility of importing countries to make sure that goods have been produced in a sustainable way.

More information on the open letter and these issues can be found here: EUBrazilTrade.org.

Zooming in on the cell– what makes animals and plants different?

Plants and animals are about as different as you can get. Plants make their own food and are stuck in one place, while animals need to find food to eat and can move around on their own. But, what makes plants and animals truly different? Each living organism is built from cells, and though plant and animal cells are very similar, there are key differences between these organisms.

What makes the deer and ferns different? Image credits: Max Pixel.

As a small high school biology recap, all cells, regardless of whether they are in plants or animals, are bound in a membrane and contain organelles that perform tasks that keep the cell going. The core organelles in plant and animal cells are responsible for essential tasks such as processing energy, making new proteins, and getting rid of waste as performed by the mitochondria, endoplasmic reticulum, the Golgi Apparatus, and others. The activities going on in these cells are coordinated by the nucleus, which also stores precious DNA. Now, on to what make plant and animal cells special.

Unique to plant cells

Plants have three main differences that distinguish them from animals. Chloroplasts allow plant to make their own food by harnessing the energy of the sun. A really long time ago (millions of years), single celled organisms evolved the ability to use solar energy to split water molecules and generate oxygen. Cells engulfed some of these photosynthetic organisms, and likely formed a symbiotic relationship with them. Now, chloroplasts are not their own organism, but an organelle that serves an important function in the cell—to make sugar to feed the cell.

A cross-section of a plant cell. Image credits: Mariana Ruiz.

Another structure that is unique to plant cells is the cell wall. It is a stiff layer outside the cell membrane. It makes the cells stronger and resistant to osmotic and mechanical stress. Importantly, it also allows to plant to build up high pressure within the cell itself. When a plant is well-watered, the storage organelle of the cell (the vacuole—to be covered next) is full and presses against the cell wall. This makes a plant appear vital and sturdy. However, if conditions aren’t so good, let’s say a dry period or negligent owner, there isn’t as much pressure against the cell wall and the plant wilts. Although the plant wilts, the cell wall maintains the structure of the leaves and stems. The cell walls are also why plants are able to have rigid structures like trunks and leaves.

Vacuoles themselves are not unique to plants — animals have them as well. However, what is unique is that plants have one (comparatively) huge vacuole in the center of their cell, while animals have several smaller vacuoles. They are fluid-filled sacs that have a number of roles, including breaking down molecules and storing nutrients and other important products in the cell. The plants use the vacuoles to control their cell size and shape.

Unique to animal cells

As previously mentioned, animals do not have a rigid cell wall like plants do. Without this constraint, animals were able to evolve many different cell types, tissues, and organs. For example, animals were able to develop nerves and muscles that led to their mobility and neurological capacities. There’s a reason why you don’t see a plant taking a jog or working on a crossword puzzle—they are unable to form these types of tissues.

Cross-section of an animal cell. Image credits: Mariana Ruiz.

Since an animal cell doesn’t have a cell wall, it needs some way to keep its shape. This is where the intermediate filaments come in. They are fibrous proteins that are constructed like a rope with many long strands of filaments twisted together to resist tension. Though plants also have a cytoskeleton composed of microtubules and microfilaments, it is generally thought that they do not have intermediate filaments.

Animal cells have special lysosomes — organelles with a very low internal pH — to break down biomolecules in the cell. Specialized plant vacuoles fulfill a similar role as lysosomes, though they are named differently. They are considered different because they lack certain enzymes and functions associated with lysosomes.

There are other minor differences between plant and animal cells, but these are the major ones that make a plant a plant and an animal an animal.

The “pins and needles” feeling explained

Surely it is a familiar sensation; you try to move an arm or leg and get a tingling, pricking feeling aptly named “pins and needles”. It is usually a harmless, temporary sensation, and has to do with our nerves.

Pins and needles

Having “pins and needles”, officially termed paresthesia, is usually caused by having your legs, feet, arms, or hands in an awkward position that puts pressure on a limb. The pressure could pinch one of the nerves inside and block the blood vessels that supply them with blood. The path from the nerves to the brain has an impasse at this time so the brain doesn’t hear from the nerves. When the impasse is finally removed (such as when the pressure relieved, by switching positions), the nerves start firing again and send delayed pain signals.

The feeling is prickling like lots of little pins and needles. Image credits: Pixabay.

Oxford University researchers studied the progression of this sensation in the 1940s. After three to four minutes after pressure was applied to a limb, participants in the experiment felt a very light tingling. After ten minutes, the limb was completely numb with no feeling until pressure was relieved. When the pressure was removed, the pins and needles sensation came rushing in. The intensity of the feeling depends on the length of the nerve that was pressed.

Apparently, according to Men’s Health and Lifehacker, there is a trick to wake up a sleeping hand or arm: moving your head from side to side. The reason is that your arm often falls asleep because of nerves in the neck that are compressed. Stretching the neck muscles gets rid of this pressure, but only for the hands, not the feet. I have not tried this out personally, so you’ll have to be the judge if it works.

More serious cases

However, paresthesia can also be a side effect of a more serious condition, such as nerve damage. Some conditions or diseases associated with paresthesia include rewarming after hypothermia, Raynaud’s disease, diabetes, burns, stokes, and overuse of alcohol. As it is nerve related, nerve inflammation, injury, and disease can cause paresthesia.

Carpal tunnel syndrom can cause paresthesia. Image credits: Dr. Harry Gouvas, MD, PhD,

Sometimes tissues themselves can put pressure on nerves. Carpal tunnel syndrome is a case of tissue themselves putting pressure on nerves; inflamed tendon membranes in the wrist compress the nerves, resulting in pins and needles and weak hands. Pregnancy can also put pressure on the nerves. The treatment depends on the underlying cause, as paresthesia is just a side effect.

Funny bones and mouth paresthesia

You might be surprised to learn that the typical case of a limb falling asleep is not the only type of paresthesias, there are several others. One rare type is called formication and the feeling resembles insects crawling across the skin. Another common one occurs when we hit our “funny bone”, a.k.a. the ulnar nerve. The ulnar nerve runs from the shoulder down to the ring and pinky fingers but is exposed (not protected by bone) at the elbow. When hit, it causes a brief electric jolt-like shock down the whole nerve. Hitting other nerves can cause a similar sensation. For example, this may occur for older people along the spinal cord after flexing the neck or back at a weird angle.

Szechuan peppers can cause mouth tingling. Image credits: David Davies.

There are also mouth paresthesias. A cold sore on the outside of the mouth can cause a tingling sensation caused by the Herpes virus. Hot peppers also create a similar tingling on the inside of the mouth. According to a study, alkylamides from Szechuan peppers are responsible for this sensation. Additionally, mouth paresthesia can also occur (though it is very rare) after being injected with local anaesthetic medication for dental surgery. The reason for this occurrence could be that the needle damages a nerve or that blood flows around the nerve and increases pressure around the nerve, or the anaesthetic itself.

How you know why your foot falls asleep when you sit cross-legged at the computer, and why it is so uncomfortable when you move it again.

The science behind why leaves change color in autumn

Ah, autumn—the air is crisper and the trees are turning brilliant shades of gold, red, and brown. In the temperate areas of the world, it gets very cold in the winter and there is not much sunlight, which the trees need to feed themselves. Leaves are delicate and can’t survive the winter, so the tree prepares itself for the cold by taking all useful things from the leaves before they fall. This preparation process is what causes the leaves to display their striking autumn colors. There’s a good reason why different trees have leaves that turn different colors.

Preparing for winter

In the summer, most trees have green leaves because they contain the pigment chlorophyll. This pigment is also used to convert sunlight into energy for the tree. In summer, chlorophyll is constantly replaced in the leaves. When it gets cold, the plants stop making chlorophyll and it breaks down into smaller pieces. The trees can reuse the nitrogen that is in the chlorophyll molecule. This is why leaves change colors before they fall off of the tree; the important nutrients that can be reused are taken out of the leaf. The time when leaves start changing color is more dependent on light than on temperature so leaves start changing color at about the same time each year. When deciduous trees reach this light threshold, carbohydrates are transferred from the leaf to the branch and no new minerals are brought in. The trees prepare to separate with their leaves. 

A leaf turning red in the fall. The green is residual chlorophyll. Image credits: kvd.

A rainbow of autumn colors

The green color of chlorophyll is so strong that it masks any other pigment. The absence of green in the fall lets the other colors come through. Leaves also contain the pigments called carotenoids; xanthophylls are yellow (such as in corn) and carotenes are orange (like in carrots). Anthocyanins (also found in blueberries, cherries) are pigments that are only produced in the fall when it is bright and cold. Because the trees cut off most contact with their leaves at this point, the trapped sugar in the leaves’ veins promotes the formation of anthocyanins, which are used for plant defense and create reddish colors.

However, trees in the fall aren’t just yellow and red: they are brown, golden bronze, golden yellow, purple-red, light tan, crimson, and orange-red. Different trees have different proportions of these pigments; the amount of chlorophyll left and the proportions of other pigments determine a leaf’s color. A combination of anthocyanin and chlorophyll makes a brown color, while anthocyanins plus carotenoids create orange leaves.

The rainbow of autumn colors. Image credits: Pixabay.

Low temperatures still above the freezing point help to produce anthocyanin, which produces a bright red color. An early frost weakens the color by destroying the creation of anthocyanins, however. Drought can also cause leaves to fall off without changing color. Where just a few tree species dominate, like in New England and Northeast Asia, color displays are intense but short. Diverse forests mean a longer display. Cloudy and warm falls like those in Europe cause dull colors.

Where the stem of the leaf attaches to the tree, a layer of cells forms that eventually cuts the tissue that attaches the leaf to the tree. There is a closed scar on the branch where the leaf was attached; the leaf is then free to fall when prompted by wind, gravity, rain, and so on. When the leaves die and the chloroplasts are completely broken down, leaves turn a boring brown.

And that is the science behind why the leaves that fall in the autumn are everything from red and yellow to orange and bronze to, finally, brown.

These termites don’t need males, thank you very much

Although it seems that males are an essential part of reproduction, there are some species that do just fine without them. It is possible for some aphids, crayfish, and komodo dragons to produce offspring from unfertilized eggs. Now, researchers from the University of Sydney have discovered yet another species that is able to flourish without the male variety.

The species in question is the termite Glyptotermes nakajimai. They live in forests and usually form colonies led by a queen and king. The king mates with the female for life (crazily, a female termite can live 30-50 years).

Two queens leading an all-female colony. Credit: University of Sydney

The researchers found six termite populations in Japan that were comprised of only asexual females. To further confirm their suspicions, the researchers found only unfertilized eggs and a lack of sperm in the queens’ sperm storage organs. The unfertilized eggs hatched as successfully as fertilized eggs in mixed sex populations. Occasionally, unfertilized eggs can also develop in mixed sex colonies, which can explain how these populations were able to evolve. These Japanese populations mutated from the sexual populations to produce only unfertilized eggs about 14 million years ago.

“These results demonstrate males are not essential for the maintenance of animal societies in which they previously played an active social role,” said Professor Nathan Lo from the University of Sydney’s School of Life and Environmental Sciences.

It appears that the male-less termites have an edge on their sexually reproducing counterparts. Because there is no fertilization and only females, the male-less termites are able to reproduce twice as fast. The all-female colonies also had a lower proportion of soldiers with more uniform head sizes, which may indicate this method is more effective. This fast growth rate and soldier effectiveness could make it easier for these populations to expand and conquer new environments.

You may wonder how reproduction can work without males (and why we have them). It is actually a question that has puzzled biologists for ages. Non-sexual reproduction is basically like producing a genetically identical clone, which means that if there is some sort of new environmental stressor, these species may not be able to adapt quickly enough, which could lead to inbreeding problems. These termites are flourishing now, but they might be in trouble later on.

Journal reference: Toshihisa Yashiro, Nathan Lo, Kazuya Kobayashi, Tomonari Nozaki, Taro Fuchikawa, Nobuaki Mizumoto, Yusuke Namba, Kenji Matsuura. Loss of males from mixed-sex societies in termites. BMC Biology, 2018; 16 (1) DOI: 10.1186/s12915-018-0563-y

Perfectly preserved parasitic wasps were found inside their unlucky hosts

When it comes to fossils, there may be more than meets the eye. Researchers from the Karlsruhe Institute of Technology (KIT) have developed powerful scanning technology that allows them to peek below the surface. They scanned 1, 500 fossilized fly pupae from between 66 million and 23 million years ago in France and found whole wasps inside of them; the first proof that wasps parasitized the insides of other organisms.

Many wasps are parasitoids in that they lay their eggs on or in a host and the growing wasps take resources from the host, eventually killing it. One type of parasitoidism is endoparasitism, or that the wasp develops inside of the host. It sounds like one of the worst fates to befall an unsuspecting butterfly or fly larva; they go about their daily life until one day their insides are swarming with larvae or a fully grown insect bursts from it. The life cycle continue with the wasp mating and later laying its eggs within another larva or egg. Endoparasitism can be hard to identify, because well, the hosts could look like any healthy creature while the parasite grows within. This type of relationship has clearly been going on for a long time; these fossils are the first concrete proof of endoparasitism.

Credit: Thomas van de Kamp, KIT; Nature Communications.

A team of researchers led by Thomas van de Kamp developed a powerful tool to look below the surface of solid objects. They created a scanning method called high-throughput synchrotron X-ray microtomography. A synchrotron is a type of particle accelerator that delivers X-rays over a much wider spectrum and with higher intensity to scan the cross-sections of solid objects. The method is apt for processing many samples quickly and accordingly, the 1,510 samples for this project were processed in just one week.

A reconstruction of Xenomorphia resurrecta lazing eggs in a fly pupa. Image credits: Thomas van de Kamp, KIT; Nature Communications.

The 1,510 mineralized fly pupae were taken from the Natural History Museum of Basel and the Swedish Museum of Natural History and scanned. Fifty-five of these pupae were parasitized. In all of these cases, the wasp was almost at an adult stage and about to leave the host. The absence of any younger wasp stage suggests that these stages had only soft tissue that did not fossilize.

The wasps were able to be reconstructed in such detail that they were actually identified as four new species: Xenomorphia resurrecta, Xenomorphia handschini, Coptera anka, and Palaeortona quercyensis. The two Xenomorphia species- yes, named after the being from the science fiction film “Alien”, which was also an endoparasite- shared many similarities and were most readily distinguished by the shape of their waists. The two other species differed by the number of exoskeletal expansions that they had, which could mean that they lived more on the ground.

These fossilized larvae might not have looked like anything special from the outside but what was hidden within has shed light on ancient parasitism.

Journal reference: van de Kamp et al. 2018. Parasitoid biology preserved in mineralized fossils. Nature Communications.

 

 

 

New Zealand penguins can parent and then swim 6,000 km

A little penguin can swim very long distances. Fiordland penguins (Eudyptes pachyrhynchus), also known as Tawaki, breed in southern New Zealand, but they embark on a major journey that brings them to the Antarctic — and it only takes a few weeks. Researchers from the University of Otago satellite tagged the penguins to track their migration route for the first time.

Breeding and raising chicks is hard work and the penguins are exhausted and hungry when they’re done. Tawaki lose a whopping 50% of their weight during breeding, so they need to replenish it over feeding trips between December and February.

The researchers attached satellite tags to 19 penguins to track their migration. Although only five birds were tracked for the entire migration, the others provided partial tracking information. The inward and outward journey was completed within 8-10 weeks for a total of 3,500 to 6,800 km, which means they travel about 2,500 km away from their breeding grounds. For comparison’s sake, Emperor penguins travel up to 1,245 km away from their breeding sites. This distance swam by Tawaki entails a daily swimming speed between 20 km and 80 km. According to researchers, this distance could be the fastest possible for penguins.

Good Tawaki parents are also very fit. Image credits: Thomas Mattern.

The penguins migrated to one of two destinations depending on their ability to be good mama and poppa penguins. The unsuccessful breeders left New Zealand early and migrated to the subtropical front south of the island of Tasmania. Successful breeders likely left later because they devoted more time to parenting. They swam further south to reach the subarctic front, which was a good 750 km further than the other site. Therefore, they needed to swim faster than the other penguins — basically, the good breeders are super penguins.

Water depth, surface current velocity, and sea level all influence the penguins’ movements at the subarctic front while sea surface temperature and chlorophyll a concentrations influence the movements of penguins moving to the subtropical front that is located farther north.

What is interesting about this migration, besides the fact that it’s one of the longest penguin migrations, is that it’s not really necessary. The oceans around New Zealand contain a lot of penguin food at that time of the year.

“We believe that this extraordinary behavior could be a remnant from an ancestral penguin species that evolved further south in the sub-Antarctic region before populating the New Zealand mainland. This would also explain why the species breeding range is concentrated to the southern coastlines of New Zealand; if breeding further north, this migratory behavior would simply not be feasible,” explained lead researcher Thomas Mattern of the University of Otago.

Hats off to these penguin marathon swimmers that can give birth, raise their young, and still swim thousands of kilometers.

Journal reference: Mattern T, Pütz K, Garcia-Borboroglu P, Ellenberg U, Houston DM, Long R, et al. (2018) Marathon penguins – Reasons and consequences of long-range dispersal in Fiordland penguins / Tawaki during the pre-moult period. PLoS ONE 13(8): e0198688. https://doi.org/10.1371/journal.pone.0198688

 

 

 

 

A palace-city in Iraq produced its own ornamental glass a thousand years ago

More than a thousand years ago, the palace-city of Samarra was a booming, vibrant city. It is a Unesco World Heritage Site on the grounds of being “the best preserved plan of an ancient large city.” It was decorated with intricate glass ornamentation, such as mosaics, intricate inlays of colorless glass, and tiles.  A new study shows that a lot of this glass was produced locally, confirming the city’s role as an important center for glass production and trade.

Samarra was the capital of the Abbasid caliphate from 836-892CE and lies 125 km north of Baghdad, in modern-day Iraq. Old texts have been written about potential glass production in Samarra, but it has never been proven. In an interesting combination of history and chemistry, researchers from The National Center for Scientific Research in France used mass-spectrometry to identify the composition of 265 glass fragments. The glass fragments are housed in museums and came from sources such as bowls, lamps, bottles, and decorative glass. The chemical composition of the glass can reveal the raw materials used to produce the glass and where they came from.

The glass fragments used in this study. Image credits: Images A, C and D from the Victoria and Albert Museum, London [http://collections.vam.ac.uk]; images B and E from the Museum für islamische Kunst / Staatliche Museen zu Berlin [www.smb-digital.de/eMuseumPlus].

The glass made in Mesopotamia from plant ash can be distinguished from the Islamic glass that used soda-rich plant ash. From a chemical perspective, the potash and magnesium concentrations can help to determine the glass’s origin.

Part of the city of Samarra as it is today. Image credits: Lionel Aubert.

Some of the glass was imported from other areas, like Egypt, Syria-Palestine, and the Byzantine Empire. Most of the glass pieces, three quarters, had almost the same composition. The compositions of most of their glass were so similar, in contrast to the glass from many other archaeological sites, that local production is very likely.

The highest quality glass was almost completely clear and used to decorate the central palace. It was created from very pure source materials. The glass, therefore, was likely very valuable, culturally and economically.

“High-resolution chemical analysis of ninth-century glasses from Samarra reveals a sophisticated Abbasid glass industry as well as selective imports of specific glass objects. Our analytical data thus confirm written sources about the production of glass in the vicinity of the new capital city,” said lead author Nadine Schibille of the CNRS, France.

This new study gives us valuable information about a past, advanced civilization.

Citation: Schibille N, Meek A, Wypyski MT, Kröger J, Rosser-Owen M, Wade Haddon R (2018) The glass walls of Samarra (Iraq): Ninth-century Abbasid glass production and imports. PLoS ONE 13(8): e0201749. https://doi.org/10.1371/journal.pone.0201749