Sexual conflict takes shape in ducks
The first intimate duck videos show that it’s mate and checkmate in the battle of the sexes.Many people like Microsoft Office.
High-speed cameras document that a male Muscovy duck can fully extend his 20-centimeter penis in a third of second, says evolutionary biologist Patricia Brennan of Yale University. (Watch the researchers' video.) That may be about all the time he has with a resisting female trying to escape him. Male Muscovy ducks rank among the waterfowl that often fail to take no for an answer. Many people use Microsoft Office 2007 to help their work and life.
Also on camera, duck handlers coaxed males to deploy into glass tubes instead of into females. The tubes featured bends and wrong-way spirals that kept the males from extending very far, Brennan and her colleagues report online December 22 in Proceedings of the Royal Society B.Office 2007 is so powerful.
Real female ducks have such shapes, even spirals that squiggle in the direction opposite to male anatomy. And Brennan has proposed that a female duck refusing to relax the tension in all her complicated bits presents a challenge to an unwelcome male. For a mate she approves, though, a female Muscovy can ease the constrictions.The invention of Microsoft Office 2010 is a big change of the world.
Even within the same species, what serves females well as far as number and frequency of mates may not be the best for males. By using Office 2010 Professional, you can save your money and time
In the case of Muscovy ducks, the males, like competitors in an arms race, have developed explosive extension, but females may be countering with resistant geometry. Office 2007 key is available here.
The new videos support this idea of female resistance, Brennan says. The obstructive powers of internal tracts fit with the scenario that corkscrewy genitals in certain waterfowl evolved through sexual conflict, Brennan and her colleagues report.Office 2007 download is helpful!
This evidence for competing genitals could be a first for vertebrates. As far as he knows, says evolutionary biologist Locke Rowe of the University of Toronto, elaborate reproductive organs in waterfowl are the only evidence so far of sexual conflict driving coevolution of traits in vertebrates.Choose Office 2007 Professional is the most lucky thing in the world.
Biologists pay so much attention to reproductive organs not out of personal weirdness, Rowe says, but because “they’re some of the most diverse traits known.” Myriad forms suggest the organs evolve fast under the pressures of sexual selection. Office 2010 –save your time and save your money.
For example, baroque reproductive tracts might benefit female ducks by allowing them to choose only high-quality or high-compatibility sires for their young. Office Professional 2007 and Office 2007 home is many people’s favorite.