Added: Burnell Sipe - Date: 07.10.2021 17:28 - Views: 17969 - Clicks: 8783
Duck mating can be surprisingly brutal, but females have a way to avoid giving birth to offspring from aggressive males.
Richard O. Ducks are different from most birds in the fact that male ducks have a penis, analogous with the mammalian or human penis. And the fact that ducks still have a penis allows them to force copulation in ways that are unavailable to other birds. Unpaired males will attempt to force copulation during the egg-laying season.
There are even socially organized groups of males pursuing females to force copulation. This is really physically harmful for the female ducks. They are stressed out. They fly away, dive, and do everything they can to avoid it. Sometimes they even drown because ducks often copulate in the water. Patricia Brennan and I, and other colleagues, started studying this about 10 years ago. We were interested both in how the very large penis of the duck functions and how that is related to this violent sexual coercion. What we discovered was that some duck species evolved ribbed and even thorny penises.
Very bizarre stuff! Co-evolving with that are a series of innovations in vaginal structures that include dead ends, cul-de-sacs, or spirals.
The male penis is counterclockwise coiled, and the female vagina Single ladies want sex Red Wing species with large penises is clockwise coiled. This is confirmed by genetic evidence. When forced copulation is as high as 50 percent, only percent of the offspring are from extra-pair males, or forced copulation. That means these ducks have a 98 percent effective contraceptive device in their bodies!
The females are still incurring all the risk and damage of resistance. But, in the face of violence, they are maintaining control over who is fertilizing their eggs. I assume an enterprising intern or journalist at one of these websites found our National Science Foundation grant to do research on duck penises and turned it into news. Suddenly, we were being discussed on Fox News by Sean Hannity and his colleagues, and across the media.
We had good defense from other folks in the media, but people were shocked to discover that their tax dollars were going to study the evolution of duck genitalia. When Darwin wrote On the Origin of Species he had no theory of genetics. He also had no theory or, at least, delayed a proposal about the evolution of human beings. He went back to Down Housecogitated for a decade or more and came up with a second book, Descent of Man, in At this point he was already world-famous for the idea of natural selection and so this new book caused a huge stir.
He knew lots of people were sympathetic, but he knew that he was going to be working with very touchy subjects: human origins, human sexuality, and sexuality in general. He wrote a very long and granular book, with lots of nitty-gritty detail, which proposed sexual selection as an independent mechanism of evolution. It had two components. One was competition within one sex, for control or access to the other sex, usually male competition.
The other was choice of mates by the other sex, which could be female choice, mutual mate choice, or male mate choice, depending on the species. His idea that male competition, in particular, was a force in evolution, was a great sell in Victorian England. The other idea, of mate choice—and female mate choice in particular—was a bomb. The other was the notion of female willfulness: The idea of females choosing mates on the basis of sensory information, in a licentious way, was very threatening! Some of the original criticism of the idea even attacked the concept as a of moral corruption.
He thought animals choose their mates because of the pleasure they have in observing and selecting them, and that was an explicit explanation for why ornaments in nature are beautiful. In bowerbirdsfor example, females have used choice preferences to make males less aggressive and more amenable. Female bowerbirds do all the work: They build the nest, lay the eggs, care for the young. But they need to choose a mate.
They do so based on the quality and beauty of a bower. Males build a bower, which is like a seduction theater where courtship takes place. In addition, the male goes out and finds a bunch of beautiful things, like flowers or butterflies or white stones, and makes a big array of interesting stuff. When the female comes to visit, the architecture of the bower is attractive, but also protective. It allows her a refuge so that she can get intimately close to the male and watch him strut his stuff while being protected from being forcibly copulated by the male.
She sits between the walls looking forward at him and his stuff. If he wants to copulate, he has to go around the bower to the back and mount her. This is shown in bowerbirds: Females receive dramatic and even violent displays because those displays are stimulating and because the females can keep their autonomy Single ladies want sex Red Wing. That applies perfectly well to humans, as well. There has been very little role for the concept of mate choice—particularly female mate choice—in the evolution of humans. Having done all this work on birds I became intrigued how some of these ideas about mate choice and sexual autonomy were providing fascinating and interesting explanations for the origin of social and sexual behavior in humans.
Male primates, for the most part, have deadly weapons in their faces, in the form of large canine fangs that sharpen themselves on the pre-molars of the lower jaw as they chew. Our immediate relatives, chimpanzees and gorillas, have prominent canine teeth in the males, which females lack. The question is: Under what conditions did human males give up these weapons?
The proposal is that, taking a lesson from bowerbirds, human mate choice may have preceded in a similar way. By making weapons like fangs unsexy, females could expand their capacity to get mates they like. The male club-winged manakin makes these harmonic sounds through stridulation, rather like a cricket. One secondary wing feather rubs its bent tip against the bumps on the swollen tip of the neighboring feather, a bit like a bow running over a violin string.
That mechanical interaction makes the thick feather ring with the sound, audible at yards away. About 1, cycles per second. My former student at Cornell, Kim Bostwickshowed that, in order to make those sounds, the wing bones of the male are enormous, particularly the trailing bone of the hind wing, where the wing feathers are attached. Even T-Rex has a hollow ulna bone.
In order to make sounds, the wing bones of the male manakin have been transformed into a structure serving both flight, as in all birds, but also attracting a mate—to sing a song. They are not solid, but they are times wider than wing bones of closely related species of manakin. The whole species has become less fit for survival because of this aesthetic elaboration. If you adopt the aesthetic, Darwinian view of nature, the beauty of bird song and plumage is the result of 10, different standards of beauty evolving over this complicated history of mate choice.
Simon Worrall curates Book Talk. Follow him on Twitter or at simonworrallauthor. All rights reserved. Share Tweet. Read This Next Sharks form years-long 'friendships,' dispelling 'lone shark' myth. But why sharks socialize is still an open question. Your next vaccine could be grown in a tobacco plant. Science Coronavirus Coverage Your next vaccine could be grown in a tobacco plant Long-awaited plant-based vaccine technology could help COVID shots reach developing countries.
Illegal gold miners in Brazil are attacking Indigenous groups.
How some rhino protectors have become a major threat to the species. Go Further. Animals Sharkfest Sharks form years-long 'friendships,' dispelling 'lone shark' myth. Animals Rare sturgeon threatened by new dams in Caucasus. Animals Wildlife Watch How some rhino protectors have become a major threat to the species. Animals Sea anemones sometimes eat ants. But why? Animals Mind-controlling parasite makes hyena cubs more reckless around lions. Environment Thawing permafrost prompts Denali National Park to reimagine its future.
Environment Heat waves kill people—and climate change is making it much, much worse. Environment Miami condo collapse highlights urgent need to adapt to rising seas. Environment The hidden toll of July Fourth fireworks. Environment Historic drought hitting Western ranchers. History Magazine Queen Elizabeth I's favorite pirate was an English hero, but his career has a dark side. Science New cancer treatments may be on the horizon—thanks to mRNA vaccines.
Science Coronavirus Coverage Your next vaccine could be grown in a tobacco plant. Science What wild chimps can teach humans about healthy aging. Travel Self-taught art is booming in the Great Lakes. Travel Ancient wines are having a moment in Italy. Partner Content Rare endemic wildlife is thriving in Masungi Georeserve. Subscriber Exclusive Content.
Why are people so dang obsessed with Mars? How viruses shape our world. The era of greyhound racing in the U. See how people have imagined life on Mars through history. United States Change.Single ladies want sex Red Wing
email: [email protected] - phone:(179) 903-6738 x 9908
How to Tell the Sex of Baby Chicks