"Now, I don't write many short stories these days, but I'm a sucker for the right kind of charity approach. And besides, I had a hypothesis I wanted to test: that every short story can be improved by adding dinosaurs and sodomy." SF author Charles Stross (metafilter's own) shares a short shaggy dog story he wrote back in 2011 containing sex, waterfowl, and reverse-engineering evolution: "A Bird In Hand."
Cocks (almost) don't have a penis, a trait common to 97% of bird species, but they can grow one when the expression of the Bmp4 gene is prevented. The expression of this gene causes the percursor of the phallus in the chick embryo to undergo apoptosis (cell death) and Bmp genes are also involved in 3 other bird traits: feather development, toothlessness and beak shape. In penis-less bird species, copulation requires a sex maneuver nicknamed the cloacal kiss (in French) which requires a full cooperation of the female (3 min of tender parrot sex). In species where males have a penis, like ducks, females are less lucky: the coevolution of the rather convoluted morphology of male and female genitalia has been hypothezised to occur through sexual conflict [many previouslies]. The evolutionary mechanisms that drove phallus reduction in most birds species are still unknown.
Researchers have found that size does matter as it relates to overall proportions of the male body (PNAS link, PDF)
Nature constantly engineers new and creative solutions to all sorts of problems—turning our stereotypes about sex upside-down along the way.
Carl Zimmer on the duck's incredibly long, corkscrew-shaped, ballistic penis.
My tale is rich with deep scientific significance, resplendent with surprising insights into how evolution works, far beyond the banalities of “survival of the fittest,” off in a realm of life where sexual selection and sexual conflict work like a pair sculptors drunk on absinthe, transforming biology into forms unimaginable. But this story is also accompanied with video. High-definition, slow-motion duck sex video. And I would imagine that the sight of spiral-shaped penises inflating in less than a third of second might be considered in some quarters to be not exactly safe for work. It’s certainly not appropriate for ducklings.[As Carl says, video links are possibly NSFW.] [more inside]
Why is the penis shaped like that? [T]he human penis is actually an impressive “tool” in the truest sense of the word, one manufactured by nature over hundreds of thousands of years of human evolution. You may be surprised to discover just how highly specialized a tool it is. Furthermore, you’d be amazed at what its appearance can tell us about the nature of our sexuality.
It's genital evolution day! Penis evolution. For my money, evolution reached it's zenith with the Argentine Lake Duck. Plenty more MeFi penis related shenanigans here , including the penis museum.
Sexual ornaments grow out of all proportion It seems that men will be men throughout the animal kindom, not just our little lonely corner of of it. Most body parts grow proportionally with the rest of the body as individuals of a species become larger, although scientists have long known that visual cues of reproductive prowess are a special case. But is this the case with everyone?
This news item turned out to be a hoax. Has Reuters been fooled again? I certainly smell a rat... (I know the original mefi link pointed to the BBC, but the BBC picked it up from Reuters)