Tag Archives: penis

A lot of “sea serpent sightings” could actually be whale boners

A sailor’s life is rough. You’re up against the weather, the sea, maybe even sea monsters — or so some sailors used to think. Since Ancient Greece, people have been describing sea monsters of various sorts, but according to one study, at least some of those monsters can be explained by something much more mundane: whale penises.

Copperplate engraving of Egede’s great sea monster. The Naturalist’s Library Sir William Jardine (publisher) Wm. Lizars (principal engraver). London & Edinburgh. Hans Egede (a Lutheran missionary) wrote that on 6 July 1734 his ship was off the Greenland coast. Those on board that day “saw a most terrible creature, resembling nothing they saw before.”.

In one of the more famous sea sighting reports, Danish Lutheran missionary Hans Egede wrote that on 6 July 1734, he and those on his ship saw a terrible sight — a “most terrible creature”, resembling nothing they had seen before. The monster, Egede reported, was longer than their whole ship.

“It had a long pointed snout and it blew [spouted] like a whale [it] had broad big flippers and the body seemed to be grown [covered] with carapace and [it] was very wrinkled and uneven [rough] on its skin; it was otherwise created below like a serpent and where it went under the water again threw itself backward and raised thereafter the tail up from the water a whole ship’s length from the body.”

Egede’s account is notable because he was an educated man and had described several whale encounters previously, and as a man who had seen some things in his life, he wouldn’t be one to be easily impressed. So what did Egede and his mates actually see?

Image credits: Paxton et al (2005).

Three researchers took on the challenge of answering that question. The lead author was Charles Paxton, a man familiar with unusual studies. A few years ago, Paxton was awarded the Ig Nobel award for a study on how amorous ostriches attempt to court humans in Britain — yes, really. The Ig Nobel award is offered to research “that cannot, or should not, be reproduced” and that “first makes you laugh, then makes you think”.

Paxton’s whale study was carried out in 2005, and the researchers looked at all the plausible actions that could fit the description. A key part of the description is the “serpent-like” description.

“Although whales are found, and can survive, without flukes (for example grey whales ), serpent-like or eel-like bodies are not usually associated with the rapid thrust that would be required to rear the whole body high out of the water,” Paxton writes.

So it seems like the monster couldn’t have been a whale. But it could have been a whale… part.

“There is an alternative explanation for the serpent-like tail. Many of the large baleen whales have long, snake-like penises. If the animal did indeed fall on its back then its ventral surface would have been uppermost and, if the whale was aroused, the usually retracted penis would have been visible.”

This seems compelling enough, but it still leaves up the matter of size for debate. Whale penises are indeed impressive, but could they have been bigger than the entire boat? Researchers suspect the answer is ‘no’, but there could be an explanation: multiple whales.

“The penises of the North Atlantic right whale and (Pacific) grey whale can be at least 1.8 meters long and 1.7 meters long respectively and could be taken by a naĂŻve witness for a tail. That the tail was seen at one point a ship’s length from the body suggests the presence of more than one male whale,” the study concludes.

To make the whale erection theory even more compelling, a separate incident from 1875 is even more likely to be a whale penis. Sailors aboard the merchant vessel Pauline reported seeing a “whitish pillar” amongst a pod of sperm whales “frantic with excitement” — a description that very well fits the whale penis theory.

Ultimately, we may never know what Egede saw, and probably not all sea serpent sightings are whale penises (though that would be an interesting study), but it seems to happen quite often, and it’s not uncommon for sea serpents to “appear” in the vicinity of whales, often even attached or “battling” a whale.

There’s even a theory that the Loch Ness monster is a whale penis, though there’s a big hole in that theory, in that Loch Ness is a lake and there are no whales in it. But otherwise, a lot of sea serpent sightings could actually be whale penises.

You can read the entire study here.


Young vet wounded by I.E.D. receives a transplanted penis

A young army veteran, left maimed by an improvised explosive device (IED), received a large section of tissue as a transplant last month. The unusual bit is that this tissue included the penis, scrotum, and a portion of the abdominal wall. This is the second successful and most complex penis transplant to be carried out in the US.

Operating room.

Operating room.
Image credits David Grant / USAF Medical Center – HL&VC.

The 14 hour-long procedure took place at the Johns Hopkins Hospital in Baltimore, Maryland last month, according to The New York Times. This is the third ever successful penis transplant ever performed, the second successful one to be performed in the US, and the first complex penis transplant ever performed — it involved the scrotum and surrounding tissue as well as the penis.

The doctors expect nerve regrowth will take some time, but they’re hopeful the patient will eventually regain the ability to urinate, have spontaneous erections, and achieve orgasm. For ethical reasons, the surgeons removed the testicles prior to the procedure; else, the recipient could have fathered children that genetically belonged to the donor, who is deceased.


The IED took both his legs above the knee and destroyed his genitals. But, the latter injury hit him the hardest.

“I feel whole again,” said the patient for The New York Times. He asked to remain anonymous due to the stigma around genital injury.

“That injury, I felt like it banished me from a relationship,” he recounts. “Like, that’s it, you’re done, you’re by yourself for the rest of your life. I struggled with even viewing myself as a man for a long time.”

He now has plans to go to medical school, settle down, and meet someone. “Just that normal stuff,” he said.

Prior to his operation, the transplant procedure was still highly experimental and only involved the penis. The first successful transplant of its kind took place in 2014 in South Africa. In 2016, Johns Hopkins performed the first successful penis transplant in the U.S. for a Boston man who lost his penis to cancer. Over the years, doctors there have refined their knowledge, seeking to provide transplants for young veterans returning from the battlefield with devastating, life-changing injuries.

The doctors performed this transplant, which Lee estimated to cost $300,000 to $400,000, for free. In the future, they hope the DoD will cover the expenses for their veterans. Ars Technica reports that According to the Department of Defense, 1,367 men, nearly all under the age of 35, returned to the U.S. from Iraq and Afghanistan with genital injuries between 2001 and 2013. Of those, 31% had injuries to the penis, and 20% had severe injuries.


Thailand’s going crazy over penis whitening, with over 100 customers queuing up every month

A new type of cosmetic surgery has Thailand firmly gripped: penis whitening.


Image credits Kinkate / Pexels.

Ever wished your family jewels were more moonstone and less… smoky quartz? Then you might want to look for the next flight to Bangkok, Thailand, and join the over 100 men who visit the Lelux Hospital every month to get their privates whitened.

Over the years, the clinic has built a solid reputation among its patients for providing quality cosmetic surgery. Its penis-bleaching days, however, started six months ago when a male customer came in complaining of “dark parts” on his groin. It was smooth if somewhat unassuming sailing for Lelux until Thursday, when the hospital released images of a man undergoing the treatment.

The great white hope

After that, fame and renown hit the clinic’s white-washed walls, with the story going viral on social media and eventually getting wide coverage on Thai television broadcasts.

“These days a lot of people are asking about it. We get around 100 clients a month, three to four clients a day,” said Bunthita Wattanasiri, a manager for the Skin and Laser department at Lelux Hospital, in an interview with AFP.

Most of the clients, she adds, are between 22 and 55 years old. Many of them are also part of Thailand’s LGBTI community. The procedure involves laser whitening for which the doctors use a “very small laser“, Wattanasiiri assured AFP.

“We have to be careful because it’s a sensitive part of the body,” she confesses.

According to skin-care product company Skintrium, laser lightening works by concentrating energy in the form of light of a specific wavelength and focusing it on the blemish. The energy delivered to the tissues results in heating of water molecules as well as direct damage to the tissues, which eventually results in the dark spot becoming obliterated.

They detail that laser lightening works on small areas at a time, so if you’re trying to lighten several spots or a larger area, “you might need to either go for more laser sessions or have a much longer single session than usual”. It’s not without risks, either. Some of the possible side-effects include pain, burning sensations, scarring or changes in skin texture, and there’s always a risk of infection developing.

All in all, a new penis-do at Lelux will cost some $650 (roughly 21,000 in the regional currency, the Thai baht) and five trips to the clinic. That being said, similar services are offered pretty widely in other countries as well. They’re increasingly popular, coat-tailing on several high-profile celebrities (think more Kardashians and less Hawking) that have admitted having these procedures done.

The procedure.

Authorities warn the procedure could be quite painful.
Image credits Lelux Hospital.

However, they have become highly sought-after in Thailand. Partly because of a cultural association between darker skin and outdoor labor in Asia, partly because of the procedure’s novelty on the market.

But it has also cleft Thailand‘s social media presence in twain. There seems to be little room for shades in this black-and-white debate, with one side asking “why not” while the other is worried that it’s just another example of imposing unnatural body standards, even going so far as to consider if the procedure is racist or not.

One 30-year old patient, who had undergone the treatment two months before, told BBC’s Thailand service that he did it “to feel more confident in [his] swimming briefs”.

“The obsession […] people nowadays can’t embrace their own skin colour,” one Facebook user commented on the clinic’s post, which raked in over 19,000 shares in two days.

It’s not the first time Lelux takes to hot waters, either. Last year, the clinic stirred controversy for promoting a cosmetic procedure called “3D Vagina”, in which the customer’s body fat was used to make their genitalia plumper.

In the end, we should all remember the color and fluff doesn’t really matter — it’s all about having a good time. My favorite commenter says she’s “not that serious about the color”, being “more concerned about the size and the moves”.


Man receives first penis transplant in the United States

A man recovering from penile cancer is the first American citizen to receive a penis transplant. The operation, a first in the United States, was performed by doctors at the at Massachusetts General Hospital in Boston. According to the doctors involved, more transplants will occur in the coming years. This is still, however, an experimental procedure at the forefront of medicine.


Credit: Pixabay

Thomas Manning, 64, had his penis removed to save his life two years ago. After surgery, he was left with a one-inch stump. He had to urinate while standing, and although he was single before when he was diagnosed with penile cancer, intimate relationships were out of the question, Manning confided to a New York Times reporter.

The hospital’s team, led by Dr. Curtis L. Cetrulo, has been preparing this operation for three years. They practiced on six cadavers, meticulously training for the difficult procedure ahead. Only two penis transplants had been performed before. The first successful penis transplant was made by doctors in South Africa in 2014, but the first attempt ended in failure in 2006 in China. The South African transplant was so successful that it ultimately resulted in a pregnancy.

The operation went on pretty smoothly, despite a post-surgery complication that caused hemorrhage. Since then, recovery went well. Doctors say in a couple of weeks Manning should be able to urinate normally, and in a few months tops, should also regain sexual function. The new penis came from a donor whose family wished to remain anonymous.

“If I’m lucky, I get 75 percent of what I used to be,” Manning said. “Before the surgery I was 10 percent. But they made no promises. That was part of the deal.”

Ultimately, this experimental procedure will go on to help veterans. From 2001 to 2013, 1,367 veterans went through genitourinary injuries in Iraq or Afghanistan. Soldiers who come back home with genital trauma have one of the highest suicide rates among veterans. “They’re 18- to 20-year-old guys, and they feel they have no hope of intimacy or a sexual life,” Dr. Cetrulo said to the NY Times. “They can’t even go to the bathroom standing up.”


Tuatara embryos reveal common origin of the phallus

Ahh, the phallus. In most sexually-reproductive species, half of the individuals lack one, while the other half is constantly trying to share theirs as much as possible with the first group, with varying degrees of success — bragging, fighting or impressing their way to the continuation of the species. Marvelous!

The tuatara. We’re gonna talk about him very soon now.
Image via wikipedia

However, for the importance it has in our lives both culturally — often associated with fertility and virility — and biologically, we don’t really know how it evolved. Did species develop it separately, as the most efficient solution to the problem of sexuality? Did we all get one from a common ancestor but some just kind-of got tired of it and developed other methods of insemination?


Tackling a hard problem

The evolution of internal fertilization was a critical step towards the diversity of amniotes (animals that lay eggs or nurture it inside the mother’s body) we see today. In most cases, this process relies on a critical step: fertilization requires the deposition of male genetic material in the form of sperm, facilitated by the phallus, inside the female’s cloaca (for birds) or vagina (for mammals). Other species, such as 97% of all bird species and some reptiles, rely on cloacal apposition.

One such reptile, the tuatara or Sphenodon punctatus, provided the team with the biological niche they needed to solve the case — though resembling lizards, they are acually part of a separate lineage, belonging to the order Rhynchocephalia.  But there was a little problem; being an endangered species since 1895, they couldn’t use recent embryos to study the reptiles in the early developmental stages they were interested in:

“As the sister group to squamates [lizards and snakes], S. punctatus occupies an important phylogenetic position for resolving amniote genital evolution; however, acquisition of new embryological material is difficult owing to the close management of this species,” the team writes.

So they set out to look for suitable material and found four specimens that were donated to the Harvard Embryological Collection (HEC) in 1909 by Arthur Dendy, who owned the most comprehensive collection of this species. One of these specimens was just what they were looking for.

“We examined the historical records and concluded that of the four S. punctatus embryos sent to Minot [then curator of the Harvard Embryological Collection], one embryo, specimen 1491, is the ideal stage at which to examine the cloacal region for evidence of genital swellings.”

Initiation of amniote external genitalia consistently begins as paired genital swellings.
(a, red arrows) Specimens taken from indicated species.
(b) Illustration of tuatara embryo 1491 from the Harvard Embryological Collection (HEC).
(c,d) This embryo possesses genital swellings (GS) and anterior swellings (AS) adjacent to the cloaca (CL) at a stage comparable with when other amniote species are undergoing external genital morphogenesis.
Image via royalsocietypublishing, credit to authors.

Specimen 1491 was histologically prepared into 8”m thick sagittal sections, but the position of the animal’s body (image b) didn’t allow the team to study the genitals directly, so they reconstituted 82 slides into a 3D model they could analyze.

The model revealed genital swellings between the hind limbs and cloaca. Another, more focused modeling, was built to analyze only the cloacal region, to better understand the relationship between the genital swellings and the cloaca. Here, one swelling is visible right next to the animal’s urogenital opening — called the urodeum — correlating to the right genital swelling in squamates, and another one anterior to the cloaca, also correlating with squamate development in this phase.

“Thus, the reconstruction of the S. punctatus cloacal region reveals the presence of the right genital and anterior cloacal swellings, indicating that although this species lacks an intromittent phallus as an adult, development of a phallus and cloacal lip is initiated in the embryo.”

“In chicken and quail, outgrowth of paired genital swellings initiates morphogenesis of the resultant genital tubercle, which later regresses owing to programed cell death. Our data indicate that the early stages of external genital development occur in S. punctatus embryos, and we suggest that the absence of an intromittent phallus in adult tuatara could result from a similar process of programmed cell death or diminished proliferation at stages later than embryo 1491,” the team concludes.

So what does this mean? Well, embryo development follows some wacky rules. When an organism evolves a new trait, it doesn’t actually loose the genetic information is had up to then, rather it’s being deactivated — this is why atavistic characteristics are sometimes developed. As the embryo matures and grows, it goes through developmental stages that won’t necessarily be retained — such as whale and dolphin embryos developing legs, then loosing them.

“A resolved hypothesis regarding the evolution of amniote external genitalia. Our observations suggest that the phallus evolved once and diversified among amniote lineages. Phylogeny after Chiari et al.”
Image via royalsocietypublishing, credit to authors.

As such, the presence of the genital swellings in an animal that lacks a phallus as an adult suggests that the organ was inherited from one common ancestor, and then developed into all the variations we see today.

“Taken together with previous studies of external genital development, the data from tuatara support the hypothesis that the amniote phallus had a single evolutionary origin that was followed by lineage-specific modifications that underlie the diversity observed in extant amniotes.”



First was the limb, then was the penis: study unravels Genitalia Evolution

A breakthrough study authored by Harvard University developmental biologists has finally resolved the mystery of how sexual organs appeared for the first time in vertebrates. According to their findings, shortly after our sea-dwelling ancestors migrated on land, creatures were pressured to quickly evolve genitalia – which they didn’t require up until then. These sexual organs, at least for snakes and lizards, originated from the limbs. The study also found that in mice, the sex organs had genetic origins in the tail bud.  I can smell a joke cooking up.

Where does this thing fit in?

At first, the researchers were interested in studying limb origin and evolution, but as the biological reverse engineering steadily unfolded before their eyes, they came across a more interesting objective – sexual organs. They soon found that if they ran the right tweaks, they could coax  embryonic limb cells of lizards and snakes to turn into genitals; the photos we received to illustrated this post may help you form a better idea of what’s going on.


Genitalia bud can be seen at the tail end of this house snake embryo

At the heart of this process lies the cloaca, a cavity typically programmed to become the lower part of the gut.  This structure sends out signals to the cells around it in the embryo, telling them to turn into genitals. By moving the position of this signaling source (the cloaca), the researchers were able to grow penises where otherwise would have been a limb or tail.

[RELATED] Ancient 385-million-year old Fish pioneered Sex

“It demonstrates that there is a flexibility with what kind of cells can get recruited during development to form genitalia,” explained lead author of the research, Dr Patrick Tschopp from the Harvard Medical School in Cambridge, US.

“What we were able to show is that if you ectopically transplant this cloaca into either limb or tail bud cells, these cells respond in a way that reflect their development being redirected to a genital fate,” he added.

“In other words, by misplacing a molecular signal you can misguide these cells in their developmental trajectory,” Dr Tschopp said.

In the case of the cloaca, as in real estate, location is everything. You might be surprised to find out that snakes have two penises. Well, now that researchers have thoroughly probed the cloaca, we know for certain why. Because in snakes the cloaca is located so close to their hind legs (or where they should have been), external genital formation is signaled to form in pair – hence the two penises (they only use one penis during mating, though). For mice,  the sex organs had genetic origins in the tail bud, because of, again, the cloaca’s position. Under the same evolutionary process, human genitalia   come from the “tail bud” as well.

The same snake embryo after 11 days, showing the budding hemipenes at the tail end in the centre of the spiral

The same snake embryo after 11 days, showing the budding hemipenes at the tail end in the centre of the spiral

This information was revealed by genetic tracing of the embryonic cells which showed what genes were turned on and off by extracting and sequencing RNA molecules, the messengers from each gene.

Why the snake has two penises

The weirdest part of the study may be, ironically, related to a rooster unfortunate enough to share a nickname with the penis. Roosters don’t actually have a penis, instead it has a hole of some sort. When he mates, the rooster engages in sex by lining up this opening with the analogous one on the hen, sending sperm from his cloaca to hers. This is the case for 97% of all birds on Earth (see ducks at your own risk for some science of the 3%).  When the Harvard researchers grafted cloaca tissue next to the budding limbs of some chicken embryos, they found that the cells in the area began to grow into genitals. This adds weight to a hypothesis that says birds (most of them) used to have a genital tubercle, just like we mammals have, only to degenerate later in their evolutionary development. More importantly, the experiment yet again shows that  something as simple as a signal’s shift in location can drastically influence an animal’s evolutionary path.

“This paper dealt with the longstanding unresolved issue of the origin of genitalia. It turns out that the mouse is the odd one out, it was not similar to the snakes or the chicken.

“This paper provides a new twist to a previous hypothesis that genitals and limbs share a deep homology [shared ancestry], it provides formal evidence of how this co-evolution between the two structures can happen in an organism.”

It’s amazing how many things this study explains in one single paper published in Nature. For instance, it elegantly demonstrates why so many animals have differently shaped genitals. In some cases where animals look almost the same,  taxonomists study genitals  to distinguish otherwise nearly identical species.

“This is a great study,” said Denis Duboule, chairman of the department of genetics and evolution at the University of Geneva, who wasn’t involved in the research. “It’s a very interesting new idea. There are these master signals during development, where cells are told to make a limb, or a pancreas. But in this case the same signal is used, and depending on where it’s sent from, it will touch different cells.”

Scientists discover the animal kingdom’s first ‘female penis’

A female insect has developed a spiky penis which it uses to get in charge . It’s a role reversal, basically: not only do the females have a penis, but the males have a vagina. The males still have sperm, but the female extracts it from the male vagina using its penis. Sounds strange, doesn’t it? Researchers thought so too.

When Neotrogla curvata insects mate, the female (top) penetrates the male.

What is the decisive factor when it comes to deciding if some animal is a male or a female? Hint: it’s not the existence or absence of genitalia. Another hint: it’s not even about the sex chromosomes, because that can get tricky in some situations. Nope, biologists rely on a simpler rule: the size of the gametes decides. As the rule goes, females are the sex that contribute the largest gametes (eggs), whereas males are the sex that contribute the smallest gametes (sperm).

In the desolate caves of Brazil, these insects copulate for days, with the females thrusting their genital organs into the males in an attempt to extract semen. It’s a weird, unique situation. Females still produce the eggs, which requires more energy consumption than producing sperm, but they also extract the sperm from the males. The reversal seems to go even deeper, as the females are promiscuous and aggressive, while the males are pretty picky.

The neoglota’s female penis (Current Biology / Yoshizawa et al.)

“The female penis is a completely novel structure,” said Yoshizawa Kazunori, an entomologist at Japan’s Hokkaido University and co-author of the study. Except for producing the larger gametes and having an egg-laying apparatus, the females in these four species of winged insects, called Neotrogla, seem to have become “very masculine” over evolutionary time, Kazunori added. The appearance of such a novel structure is exceptionally rare, he said, and “may be comparable with the origin of insect wings.”

Not all animal species have a male penis, but a female penis is a first, says Yoshizawa. There should be a good reason for such an extreme adaptation, but scientists don’t know it yet. To make it even more strange, the process is apparently pretty painful and dangerous for the male. When the insects mate, the female mounts the male and penetrates deep into a thin genital opening in his back. Her organ starts to swell, and multiple spiky spines act as grappling hooks to anchor her tightly to the male. As Nature explains, when researchers tried to pull apart two mating insects, the female was gripping so tightly that the male was accidentally ripped in half, leaving his genitalia still attached to the female – that’s how tightly the spikes hold on.

But things get even weirder. Such a dramatic adaptation doesn’t occur all at once, and structures show a gradual change. 

“Usually, a new structure evolves as a modification of a previously existing structure,” he said. But this female penis has no precedent. Evolving a structure like this, Yoshizawa said, is “exceptionally difficult” because the development of this form of mating would have necessitated the harmonious evolutions of both male and female genitalia, and their exact match.

The reason why the females developed a penis could be hunger; in the caves where they live, food is pretty scarce (usually consisting of bat droppings). Since producing eggs requires more energy, females found an alternative food source: the males’ mate’s semen capsule. This would also explain why they are more promiscuous – if they mate more, they eat more. Yoshizawa and his colleagues are now working on establishing a healthy population in the lab, so they can study the species in a controlled environment. The biggest problem is replacing their food – which is bat droppings.

Scientific Reference: Yoshizawa, K., Ferreira, R. L., Kamimura, Y. & Lienhard, C. Curr. Biol.http://dx.doi.org/10.1016/j.cub.2014.03.022 (2014).

Why did the chicken lose its penis? Science explains

The case of birds missing out on a proper penis has been a longstanding mystery in evolutionary biology. Roughly 97% of avian species sport little or nothing like a real phallus, yet they still reproduce via internal fertilization. A new study, conducted by Martin Cohn, a developmental biologist at the University of Florida in Gainesville and published in Current Biology has shown that the development of chicken penises is cut short by signals that promote cell death – a novel and unexpected phenomenon.


“This paper would be in Nature or Science if it were about people,” says Richard Prum, an evolutionary ornithologist at Yale University in New Haven, Connecticut. “The whole result is entirely novel.”

Male chicken possess only a rudimentary phallic nub, which they use to pump their sperm into females using a ‘cloacal kiss’. The cloaca is the posterior opening which birds use for both excretion and reproduction. The rooster presses his cloaca against the female’s and squirts his sperm inside; on the other end of the penis spectrum, ducks have very long and elaborate penises, which measure about half of their body lengths. To better understand the differences between ducks and chicken, biologists analyzed the embryos of the two species.

They made some very fine cuts through duck and chicken eggs, through which they observed the development of their penises (for science!). What they found was that initially, the penises of the ducks and chicken develop in the same way, but about in the nineth day, that of chicken stops growing, and in fact, starts to shrink.

“We expected to find some critical outgrowth factor was missing,” says Cohn, but the team discovered that many of the same genes that drive penis growth in ducks continued to be strongly expressed in chickens. There is a key difference between the two species, however. Chickens showed increased levels of Bmp4 — a protein that promotes cell death — near the tip of the tubercle. “We were very surprised,” Cohn says.

They then tried to override the genetic system, and treated a chicken with Noggin, a protein that blocks Bmp activity. After a day, the Noggin-treated side grew to about 6.5 times the length of the untreated side. Also, when treating ducks with Bmp, they noticed that the duck’s penis stopped growing and started shrinking – just as it happens with chicken.

So we now know the ‘how’, but we still don’t know the ‘why’. Cohn suggests that phalluses may have been lost as a secondary consequence of evolution in other body parts such as limbs and teeth – a development which altered the production of Bmp. But other researchers have different theories. Bob Montgomerie, an evolutionary biologist at Queen’s University in Ontario, Canada suggests that since the cloacal kiss requires voluntary participation from both members, female chickens and other birds may have selected males with smaller penises in part to escape forced copulation. Over time, males with smaller and smaller penises reproducted more, and this shaped the evolution of their penises.

Via Nature

How the human penis lost its spines

It’s been long theoretized by most women, and not only, that there is a connection between the penis and the brain – and research done by Gill Bejerano, a biologist at Stanford University School of Medicine, and colleagues seems to support that theory, at least in a way.

Let’s look at our close relatives, the chimpanzees. Humans and chimps share over 97% of DNA, but it’s safe to say that between them and (most) humans there are some major differences in terms of appearance, and especially intellect. For example, we know that humans have larger brains, and within the brain, specifically a bigger angular gyrus, a region associated with abstract concepts, among others.

We also know that chimps have smaller penises which also have spines; don’t think about hedgehogs or anything, but just enough to make it… a little bumpy.

The team of researchers in case wanted to have a deeper understanding (no pun intended) of why these differences appear, so they analyzed genomes of humans and closely related primates and discovered more than 500 regulatory regions (the points which tell genes what to do) that chimps and other primates have, and humans don’t. In other words, they found out what parts of the genome humans lost through millions of years of evolution.

Think about it in terms of lightbulbs and switches: the light bulbs are the genes, while the switches are these DNA controlling sequences. If you have no bulb, you can’t turn it on and off; now think about a bulb that has five different switches that control it and can turn it on in different places and at different times. If you take one of them away, the bulb still works in four situations, but not in the fifth.

The study basically looked at two of these switches, and in order to analyze them, they took the switch information from chimps and hooked it up to what is called a receptor gene, a gene whose effects can be easily tracked. They injected this information into a mouse egg, to track the progress. They found that one switch makes sensory whiskers develop on the face and spines on the penis.

“This switch controls the expression of a key gene that’s required for the formation of these structures,” said David Kingsley, a study co-author at Stanford University. “If you kill that gene — smash the lightbulb — which has been done previously in mouse genetics, the whiskers don’t grow as much and the penile spines fail to form at all.”

You can read the full article over at Nature.

“It is detective work and a great reminder that, in the course of evolution, information is both gained and lost,” said Sean Carroll, an expert in animal genetics and evolution at the University of Wisconsin, Madison.

“As so often with very good ideas, it seems almost obvious in hindsight,” said Svante PÀÀbo, who directs the genetics department of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and was part of the team that recently sequenced the Neanderthal genome. “Since two of the almost 500 deleted sequences they identified turn out to be interesting, I am sure that several other ones on their list will turn out to be interesting too,” he added. The researchers are continuing to analyse the remaining 508 DNA sequences.