Tag Archives: eggs

Fossil Friday: 1,000-year-old egg found whole in a cesspit in Israel

Researchers at the Israel Antiquities Authority (IAA) report finding an unusual and exciting fossil: a 1000-year-old, unbroken chicken egg preserved in an unfortunate place.

The ancient egg. Image credits: Dafna Gazit, Yoli Schwartz, Gilad Stern, Israel Antiquities Authority.

It might be hard to imagine this today, but for the majority of human history, poultry was a rather exotic meat. Sacrificing a laying bird for its meat meant giving up all the eggs it would potentially lay in the future — an extravagant waste. Male birds, or those too old to lay eggs, were an exception to this rule. Still, chicken farming was quite common all around the world, as the birds themselves are easy to care for and provide a constant source of food.

Finding evidence of that farming as an archeologist, however, is no easy feat. Which makes the IAA’s discovery all that more exciting.

Unbroken

“Eggshell fragments are known from earlier periods, for example in the City of David and at Caesarea and Apollonia, but due to the eggs’ fragile shells, hardly any whole chicken eggs have been preserved,” said IAA archaeologist Dr. Lee Perry Gal.

“Even at the global level, this is an extremely rare find.”

The fossilized, unbroken egg was discovered at the site of Yavne, on Israel’s southern Mediterranean coast, in an Islamic-era cesspit. The “soft human waste” material it found itself in helped keep it intact over the centuries, the team explains, an example of “unique preservation”.

Poultry farming in Israel has its roots in the Hellenistic and Early Roman periods, starting roughly 2,300 or so years ago. Later, during the Islamic period (from around the 7th century CE), poultry farming became even more popular. This coincides with a noticeable decrease in the quantities of pig bones found at various archeological sites in the region.

Although faith definitely played a part in this shift (the consumption of pork is completely forbidden in the Islamic faith), sheer practicality also played a part. People living in the region around this time needed a reliable source of protein that wouldn’t need to be preserved or kept cool to prevent spoiling over short periods. Eggs, and to a lesser extent, chicken meat, served that purpose, Gal explains.

“How did the egg end up in the cesspit? We will never know,” the archaeologists said.

“Unfortunately, the egg had a small crack in the bottom so most of the contents had leaked out of it. Only some of the yolk remained, which was preserved for future DNA analysis.”

Several other items were retrieved from the same cesspit, including bone dolls typical of the Islamic period, dating back probably around 1,000 years or so.

Did a study claim there’s no link between eggs and cholesterol? It might be biased

You’ve probably read at some point a news story or research claiming eggs don’t actually raise cholesterol levels. But those findings may have been biased because of faulty industry-funded research, according to a new review.

Image credits: Wikipedia Commons

A group of researchers from the Physicians Committee for Responsible Medicine looked at all the research studies from 1950 to March 2019 that assessed the effect of eggs on blood cholesterol levels. They studied funding sources and if they influenced the findings.

The results, published in the American Journal of Lifestyle Medicine, showed that before 1970 the industry didn’t have a role in cholesterol research. But industry-funded studies increased over time, from none in the 1950s to 60% in 2010-2019 — and industry-funded studies are well known to be associated with biases.

“In decades past, the egg industry played little or no role in cholesterol research, and the studies’ conclusions clearly showed that eggs raise cholesterol,” said study author Neal Barnard. “In recent years, the eggindustry has sought to neutralize eggs’ unhealthy image as a cholesterol-raising product by funding more studies and skewing the interpretation of the results.”

As a whole, more than 85% of the studies the researchers looked at, no matter if they were funded by the industry or not, found that eggs have negative effects on blood cholesterol. But those industry-funded downplayed the findings, the researchers claimed.

That means that when the data showed cholesterol levels increased because of egg consumption, the conclusions focused on something else. Almost half of the industry-funded studies had conclusions that didn’t match with the actual study results, compared to 13% of the non-industry funded studies.

For example, a 2014 study, associated the addition of two eggs at breakfast five days a week over 14 weeks to mean LDL cholesterol. Despite the results, the investigators said that an extra 400mg per day of dietary cholesterol didn’t affect blood lipids.

Such studies didn’t just cause misleading headlines, there have also been implications in policies. Back in 2015, the U.S. Dietary Guidelines Advisory Committee said that “available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol.”

Nevertheless, after looking at the evidence, the US government didn’t carry that statement forward in the final guidelines, which called for eating “as little dietary cholesterol as possible.”

“The egg industry has mounted an intense effort to try to show that eggs do not adversely affect blood cholesterol levels,” added Dr. Barnard. “For years, faulty studies on the effects of eggs on cholesterol have duped the press, public, and policymakers to serve industry interests.”

There have been many meta-analyses that concluded that egg consumption does raise cholesterol levels. A 2019 study showed that eating an egg each day raises low-density lipoprotein (LDL, or “bad”) cholesterol by about nine points. The study found that every 100 milligrams of added dietary cholesterol raised LDL cholesterol levels by about 4.5 mg/dL.

The report published in the American Journal of Lifestyle Medicine analyzed 153 studies, 139 of which showed eggs raise blood cholesterol — and not a single one of them reported a significant net drop in cholesterol concentrations associated with egg consumption.

Northern white rhino eggs fertilized in bid to save the species

In about 10 days’ time, we’ll see if it worked or not.

Researchers in Italy report fertilizing eggs collected from the last two females of the species. There are no living male northern white rhinos currently in the world, so the team used frozen sperm from Sudan, the now-dead last male.

In about 10 days, we’ll know if any have developed into an embryo. The plan is to help the species reproduce via a surrogate mother rhino.

All the eggs in one basket

“We expect some of them will develop into an embryo,” says Cesare Galli, co-founder of the Avantea lab where the work was carried out. Galli is also the corresponding author of the study detailing the process.

The female rhinos currently live at Ol Pejeta, a wildlife conservancy nearly three times the size of San Francisco in the heart of Kenya. Out of the 10 eggs that were recovered in June, only 7 could be used in the process.

The male, a 45-year-year-old named Sudan, became “The Most Eligible Bachelor in the World” on the Tinder dating app in a fundraising effort. He was euthanized after age-related complications last year. Researchers froze his sperm as they prepared for this current procedure. Galli quips that it is better not to “get to the last two individuals before you use this technology.”

The end goal is to raise a herd of at least five individuals and re-introduce them in their natural habitat, which could take decades to accomplish.

In the meantime, there’s the issue of poaching. The northern white rhino was driven extinct by poachers killing the animals for their horns. Advocacy group Save the Rhino says that roughly 2,360 northern white rhinos roamed Chad, the Central African Republic, Sudan, the Democratic Republic of the Congo, and Uganda as recently as 1960. By 1984, it dropped to about 15.

Other rhino species are also prey for poachers, but they’re not in as dire shape as the northern white. Reintroducing five animals into the wild won’t do any good as long as there are still poachers around.

The paper “Embryos and embryonic stem cells from the whiterhinoceros” has been published in the journal Nature.

Eggs aren’t really bad for your heart, despite common misconceptions

There is a lot of conflicting evidence when it comes to the health effects of eggs, but a new study found that eating up to 12 eggs a week doesn’t raise cardiovascular risk.

Lead researcher Dr. Nick Fuller from the University of Sydney had participants aim to maintain their weight while embarking on a high-egg (12 eggs per week) or low-egg (less than two eggs per week) diet. The participants’ cardiovascular risk was monitored, and there was no difference between those who ate few or many eggs. Essentially,  at all stages of the research, both groups showed no adverse changes in cardiovascular risk markers

Researchers also report that replacing the “bad” fats with the “good” fats did make a really big difference in terms of cardiovascular risk.

“Despite differing advice around safe levels of egg consumption for people with pre-diabetes and type 2 diabetes, our research indicates people do not need to hold back from eating eggs if this is part of a healthy diet,” Dr Fuller said.

“A healthy diet as prescribed in this study emphasised replacing saturated fats (such as butter) with monounsaturated and polyunsaturated fats (such as avocado and olive oil),” he added.

For those worrying about the extra pounds, researchers also have good news: egg consumption had no impact on weight loss or gain. Since the participants suffered from pre-diabetes and type 2 diabetes, monitoring weight evolution was important for the study.

“Interestingly, people on both the high egg and low egg diets lost an equivalent amount of weight – and continued to lose weight after the three month intended weight loss phase had ended,” Fuller said.

Researchers also comment that because of the mixed opinions people have of eggs, they often tend to overlook the nutritional benefits of eggs.

“While eggs themselves are high in dietary cholesterol – and people with type 2 diabetes tend to have higher levels of the ‘bad’ low density lipoprotein (LDL) cholesterol – this study supports existing research that shows consumption of eggs has little effect on the levels of cholesterol in the blood of the people eating them,” Dr Fuller explained.

Studies have found conflicting results about a possible connection between egg consumption and type two diabetes. A 1999 prospective study of over 117,000 people by the Harvard School of Public Health concluded, in part, that “The apparent increased risk of CHD associated with higher egg consumption among diabetic participants warrants further research.” A 2008 study wrote that the “data suggest that high levels of egg consumption (daily) are associated with an increased risk of type 2 diabetes.” However, a further study from 2010 found no connection between eggs and diabetes. Two meta-analyses also reported conflicting results.

This latest study seems to suggest that eggs are indeed harmless if consumed in moderation, but that’s unlikely to quench this debate anytime soon.

The study was published in the American Journal of Clinical Nutrition.

Eggs of different shapes and sizes. The best predictor of an egg's shape is the bird's flight ability, a new study suggests. Credit: Harvard Museum of Comparative Zoology.

Why do bird eggs come in so many different shapes ? Look to the wings, biologists say

Eggs of different shapes and sizes. The best predictor of an egg's shape is the bird's flight ability, a new study suggests. Credit: Harvard Museum of Comparative Zoology.

Eggs of different shapes and sizes. The best predictor of an egg’s shape is the bird’s flight ability, a new study suggests. Credit: Harvard Museum of Comparative Zoology.

Ask anyone on the street what an egg looks like and, after a couple awkward seconds and a bewildered look, you’d likely hear ‘oval-shaped’. Sure, that’s what a chicken egg looks like but there are 18,000 or so species of birds on this planet and the shapes bird eggs can take are far more varied than what most people are used to. You can find eggs shaped like raindrops, ping-pong balls or even Tic-Tacs.

Biologists and animal behaviorists have always been aware of this but what governs egg shape had until recently eluded science. A motley crew of evolutionary biologists, physicists and applied mathematicians from the United States seem to have cracked this stubborn egg. Their work

The researchers devised a software called the Eggxtractor which sorts and classifies eggs based on their ellipticity and asymmetry. Nearly  50,000 eggs, representing all major bird orders, were plotted using data from a database of digital images by the Museum of Vertebrate Zoology in Berkeley, California. At once, they could tell the eggs varied from spherical, to elliptical, to very pointy, to almost everything in between. But how do the eggs acquire such varied shapes?

Mary Caswell Stoddard, an assistant professor of ecology and evolutionary biology at Princeton University, and colleagues decided to look at the egg’s membrane rather the shell itself. It’s the egg’s membrane — that film you can see when peeling a boiled egg — that’s essential to an egg’s shape.

There are two main parameters which can explain an egg’s shape, the researchers learned. One’s the membrane’s composition and the other is the difference in pressure applied to the membrane before the egg hatched. By tweaking these two parameters, the team was able to recreate the entire range of avian egg shapes.

Later, Stoddard and colleagues turn to another question: why do birds lay such differently shaped eggs in the first place? They looked at various hypotheses. One suggests egg shape is influenced by the location of a nest. A cliff-nesting bird, for instance, will lay pointy eggs because these are less inclined to roll off the cliff. Another popular hypothesis is that birds lay eggs in shapes that pack together neatly in different-size clutches.

What the researchers found instead was that egg shape was most strongly correlated with the bird’s wing shape; specifically with the hand-wind index which is a measure of wing shape that reflects flight ability. It seems a bird’s aerodynamics has a net effect on the eggs it lays, as reported in the journal Science.

Very good fliers, for instance, have internal organs structured in such a way that they couldn’t handle pointy or elongated eggs. Murres are fast and powerful fliers and have asymmetric eggs, as do least sandpipers, birds which are known to migrate over very long distances. Sometime in the egg shell’s 360-million-year-old evolutionary history, nature found a way to optimize flight and egg carrying.

“Our study challenges some of the old assumptions about why eggs come in a variety of shapes,” Stoddard said. “On a global scale, across birds, we find that it’s not nest location or clutch size that predicts egg shape — it’s flight ability.

Forget eggs: This terrifying 250-million-year-old dinosaur gave birth to live babies

A remarkable ‘terrible-headed lizard’ fossil found in China shows an embryo inside the mother — a clear evidence that some reptiles were giving birth to live babies.

This is an artist’s impression of what Dinocephalosaurus might have looked like.
Credit: Drawn by Dinghua Yang

A quarter billion years ago, what is now Southwest China was covered by a shallow sea. Within that sea, some pretty big and nasty-looking creatures roamed the days, including the Dinocephalosaurus. Dinocephalosaurus had a hugely elongated neck and liked to swallow its prey whole — this being a significant detail. Paleontologists have found a fossil of such a sea monster, which is exciting enough, but within it, they found something else: another fossil. At first, they thought it was the dinosaur’s lunch, but the embryo faced forward, as opposed to any potential prey which would be swallowed head-first. Making this distinction was not easy.

“I was not sure if the embryonic specimen was the last lunch of the mother or its unborn baby,” said Jun Liu, a paleontologist at the Hefei University of Technology in China, and leader of the study. “Upon closer inspection and searching the literature, I realized that something unusual had been discovered.” Furthermore, the somewhat curved position was typical for am embryo. “The curled posture of the embryonic skeleton is also typical for vertebrate embryos,” Liu said.

Professor Jonathan Aitchison, who was also involved in the study, said this provides the first evidence of live birth in a class of animals thought to only lay eggs.

“Live birth is well known in mammals, where the mother has a placenta to nourish the developing embryo,” Professor Aitchison said. “Live birth is also very common among lizards and snakes, where the babies sometimes ‘hatch’ inside their mother and emerge without a shelled egg.”

Dinocephalosaurus, which means “terrible-headed lizard”, was not technically a dinosaur — it preceded dinosaurs by a few million years. However, it does belong to a group called archosauromorpha, a clade that includes the animals which later became crocodiles, alligators, birds and of course, dinosaurs. Even by modern standards, finding a member of this clade giving birth to live babies would be unusual, but for a member this old it is indeed stunning.

Being an aquatic reptile, it would be expected of Dinocephalosaurus to lay its eggs on dry land, like turtles do. But because of its very particular shape and its long neck, it was completely unsuited for trips out of the water. When your neck is a third of your total body length, you’d much rather stay underwater, which is arguably why the creatures developed this birthing mechanism.

Professor Chris Organ from Montana State University, who also worked on the study, said evolutionary analysis showed that this instance of live birth was also associated with genetic sex determination.

“Some reptiles today, such as crocodiles, determine the sex of their offspring by the temperature inside the nest,” he said. “We identified that Dinocephalosaurus, a distant ancestor of crocodiles, determined the sex of its babies genetically, like mammals and birds. This new specimen from China rewrites our understanding of the evolution of reproductive systems.”

But not everyone is convinced. Michael Caldwell, an expert in extinct marine reptiles and chair of the biological sciences department at the University of Alberta says that Choristodera, a group of semi-aquatic reptiles, gave birth to live young, too. The only question is whether they too can be placed under the archosauromorpha, which according to Caldwell, are “a giant grab bag” of seemingly disparate animals. But in the grand scheme of things, whether it’s Dinocephalosaurus or Choristodera that can lay a claim to fame is not relevant. What is important is understanding how environmental pressures pushed these creatures towards this unusual approach. Also, perhaps instead of wondering why these creatures did get pregnant, we should ask ourselves why their descendants don’t.

Journal Reference: Jun Liu, Chris L. Organ, Michael J. Benton, Matthew C. Brandley, Jonathan C. Aitchison. Live birth in an archosauromorph reptile. Nature Communications, 2017; 8: 14445 DOI: 10.1038/ncomms14445

 

Eggs !!

Study: Eat Eggs at Breakfast to Avoid Evening Snacking

Eggs !!

A study published in the American Journal of Clinical Nutrition has found that a breakfast rich in protein can help to prevent unhealthy snacking in the evening.

Lead researcher Heather Leidy said that protein in the morning significantly improves appetite control throughout the day and particularly in the evening when many snack on high fat or sugary foods. This study is one of the first to assess how breakfast affects both appetite and evening snacking in young people who usually skip breakfast.

[RELATED] Breakfast sandwich? The effects are felt before lunch

Three Scientific Study Groups

During the study overweight women were split into three groups; no breakfast, a breakfast of eggs and lean beef or a typical breakfast of ‘ready to eat’ cereal. Each meal delivered 350 calories and the same amount of dietary fat, fibre and sugar.

Participant blood samples were taken throughout the day and each woman completed a series of questionnaires. Each participant also underwent a functional MRI just before dinner to assess brain signals related to food motivation and reward driven eating behaviour.

The study showed that a breakfast of eggs and lean beef had a significant impact on satiety throughout the day as well as reducing brain activity responsible for food cravings. The result of which led to reduced evening consumption of high fat and high sugar snacks.

Leidy said:

“These data suggest that eating a protein-rich breakfast is one potential strategy to prevent overeating and improve diet quality by replacing unhealthy snacks with high quality breakfast foods.”

While it may be difficult initially to switch to a high protein breakfast, Leidy suggests trying plain greek yoghurt, cottage cheese or a handful of nuts as good alternatives to reaching the recommended 35 grams of protein.

This study builds on a previous 2011 paper published in the journal Obesity which found that a protein rich breakfast can help to control food cravings during the day.

A high protein breakfast will also help to maximise the muscle building potential early morning training sessions according to a study published in Medicine and Science in Sports and Exercise.

Peanut Butter & Honey

6 Ideas for a Protein Packed Breakfast

  • Peanut Butter Banana Sandwich – 10 grams of protein
  • Whole Wheat Waffle with Maple Yogurt – 13 grams of protein
  • Peanut Butter and Banana Oatmeal – 21 grams of protein
  • Honey Nut Parfait – 16 grams of protein
  • Veggie Fritatta – 21 grams of protein
  • Good old fashioned Bacon and Egg Sandwich – 30 grams of protein

The chicken came before the egg – hen lays ‘eggless’ chick in Sri Lanka farm

The age-old question of who came first – the chicken or the egg – has been pondered countless times, and put great thinkers throughout history in a predicament. An oddity of nature which recently occurred on a Sri Lankan farm may offer clues towards answering the riddle. There a hen gave birth to a chick without an egg, which is normally formed and healthy, according to veterinarians.

Instead of laying the egg and incubating it in a nest, the egg was incubated inside the hen for 21 day and hatched inside the mother, which died from the internal wounds. A later examination showed that the fertilized egg had developed within the hen’s reproductive system but stayed inside the hen’s body until it hatched.

Two years ago, researchers  from Scotland and England used a supercomputer called HECToR to analyze in high detail a chicken eggshell and determined the vital role of a protein used to kick-start the egg’s formation – a protein only found in a chicken. The protein had been identified earlier by scientists and was known to be linked to egg formation, now described as a catalyst. At the time, this was deemed as a scientific proof that the chicken definitely came before the egg.

First heard on BBC.

The fossilized titanosaur egg reveals the sausage-shaped structures that are likely preserved wasp cocoons. Coin added for scaling purposes. (c) Jorge Genise

Ancient wasps used to grow inside rotting dinosaur eggs

The fossilized titanosaur egg reveals the sausage-shaped structures that are likely preserved wasp cocoons. Coin added for scaling purposes. (c) Jorge Genise

The fossilized titanosaur egg reveals the sausage-shaped structures that are likely preserved wasp cocoons. Coin added for scaling purposes. (c) Jorge Genise

A recent discovery made by Argentinian paleontologist uncovered wasp cocoons hidden inside the 70 million year old fossilized egg of a titanosaur sauropod, suggesting that these ancient wasps used to dwell, consume and breed inside of them.

The find was made after researchers carefully analyzed one of the five titanosaur eggs uncovered back in 1989 in the Patagonia region of Argentina, and saw that  one of the broken eggs contained tiny sausage-shaped structures. These structures were an inch long and 0.3 inches wide, making them a perfect match for the shape of a wasp cocoon, namely the  Cretaceous wasp Rebuffoichnus sciuttoi, researchers believe.

Titanosaur was the largest creature to have ever walked the Earth, and while fossils of its eggs and that of wasp cocoons have been found before in considerate numbers, this is the first time they’ve been found together, suggesting a new relationship in the ancient ecosystem.

Diagram showing titanosaur nest excavation and egg laying

Diagram showing titanosaur nest excavation and egg laying

The wasps weren’t responsible for the damage of the eggs, however – they were too small and weak to break the thick titanosaur egg shell. Analyzing the various fractures in the eggshell, as well as other preserved insects found inside the egg, paleontologists theorize that it was open by force by some dinosaur scavenger who would’ve sucked its content dry. A second wave of creatures, likely ancient spiders, then came to dine on the now rotting egg, before finally the wasps attacked the spiders or even the initial scavengers. They would’ve then laid their eggs inside their targets’ bodies. The wasp offspring then spun their cocoons inside the rotting egg.

“Some cocoons have a truncated end that indicate the emergence of adult wasps,” study researcher Laura Sarzetti, of the Museo Argentino de Ciencias Naturales, told LiveScience.

“The presence of wasps, which are at the top of carrion food web[s], suggests that a complex community of invertebrates would have developed around rotting dinosaur eggs,” the researchers write in the journal article.

Now, although the bugs profited off the death of this particular egg, the critters were probably key in keeping titanosaur nests clean overall, added co-author Laura Sarzetti, another entomologist at the museum. For many dinosaurs, egg laying sites were kept in the same relative position for generations, and as such a cleansing of the decaying material left over from previous hatching was extremely important.

The newfound fossil cocoons are described in the July issue of the journal Palaeontology.