Navigation Links
Female Ducks Develop Complicated Genitals to Outwit Aggressive Males

Rape is a monstrous violation of a woman's freedom. But in a patriarchal society with lopsided values, there seems to be no escape from it . But ducks seem to show a way out.

Females in certain species have developed complicated genitals that frustrate aggressive male ducks, scientists have found.

A team of biologists at Yale University in Connecticut and the University of Sheffield in Britain stumbled upon the astounding biological answer to rape when they were trying to figure out why some species of birds had penises and some did not.

"Birds are the only group where it mostly has been lost -- 97 percent of birds do not have phalluses at all," Patricia Brennan said in a telephone interview.

"So if it is such a handy tool, why don't they have them any more?" Brennan asked.

Instead, they mate using what biologists call a "cloacal kiss" -- a brief touch of the single opening that birds of both sexes have for disposing of waste and that both eggs and sperm come out of.

Brennan noted that in many species, females choose a mate after he puts on an elaborate courtship display, and breeding pairs are often monogamous.

An exception is ducks -- especially mallards. Although mallards pair off to mate, females are often raped by stray males.

Still the ducklings born of consensual sex seem to be the norm. That was puzzling and so Brennan's team looked at a lot of duck bottoms.

What they found surprised them -- corkscrew-shaped oviducts, with plenty of potential dead-ends.

"Interestingly, the male phallus is also a spiral, but it twists in the opposite, counterclockwise, direction," said Yale ornithologist Richard Prum in a statement.

"So, the twists in the oviduct appear designed to exclude the opposing twists of the male phallus. It's an exquisite anti-lock-and-key system."

Brennan believes females evolved convoluted oviducts to foil the male r apists. Dr. Brennan argues that elaborate female duck anatomy evolves as a countermeasure against aggressive males. Once they choose a male, theyre making the best possible choice, and thats the male they want siring their offspring, she said. They dont want the guy flying in from who knows where. It makes sense that they would develop a defense.

Dr. Brennan suspects that the female ducks can force sperm into one of the pockets and then expel it. It only makes sense as a barrier, she said.

To support her argument, Dr. Brennan notes studies on some species that have found that forced matings make up about a third of all matings. Yet only 3 percent of the offspring are the result of forced matings. To me, it means these females are successful with this strategy, she said.

Dr. Brennan suspects that when the females of a species evolved better defenses, they drove the evolution of male phalluses. The males have to step up to produce a longer or more flexible phallus, she said.

"You can envision an evolutionary scenario that, as the male phallus increases in size, the female creates more barriers. You get this evolutionary arms race," Brennan said.

Only if the female is relaxed and cooperative can the male's sperm get anywhere near the unfertilized eggs, the researchers suggest.

"What I think is really cool is this does speak a lot about the ability of the female to have these cryptic mechanisms of choice," Brennan said.


'"/>




Related medicine news :

1. Vitamin E supports Female Hearts
2. Genetic differences found between Male and Female brains
3. Female Smokers More Prone To Lung Cancer
4. The Success Rate Of Angioplasty In Female Patients Low
5. FDA Diminish Hopes On ‘Female Viagra
6. Have You Ever Wondered Why Male And Female Voices Differ?
7. Female Twins Have More To Share Than Just The Similarity: Risk Of Early Menopause
8. Hepatitis B A high cause of Asian Female Mortality
9. Female Condoms In The Offing
10. Sexual Harassment A Cause Of Deteriorating Health Among Female Flight Attendants.
11. The Chemistry Of Sexual Attraction Between Male And Female Elephants
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:10/13/2017)... Calif. (PRWEB) , ... October 13, 2017 , ... Many ... dementia. However, many long-term care insurance companies have a waiver for care if the ... 90-day elimination period, when the family pays for care, is often waived, so the ...
(Date:10/13/2017)... NY (PRWEB) , ... October 13, 2017 , ... Ellevate ... people in business to advocate for action towards gender equality at their inaugural Summit ... from around the globe, and reached a social audience of over 3 million. To ...
(Date:10/13/2017)... Abilene, Texas (PRWEB) , ... October 13, 2017 , ... ... publication this week that explains one of the most popular and least understood books ... seems like cryptic and puzzling descriptions that have baffled scholars for centuries. Many have ...
(Date:10/13/2017)... ... October 13, 2017 , ... Coveros, a ... has been awarded a contract by the Center for Medicare and Medicaid Services ... accelerate the enterprise use of Agile methodologies in a consistent and high value ...
(Date:10/13/2017)... (PRWEB) , ... October 13, 2017 , ... “America On ... Christian identity. “America On The Brink” is the creation of published author, William ... several great-grandchildren. As a WWII veteran, he spent thirty years in the Navy. ...
Breaking Medicine News(10 mins):
(Date:9/22/2017)... 2017 AVACEN Medical (AVACEN) announced that its ... helping those with the widespread pain associated with fibromyalgia ... in Essex, England commented, "I ... experiencing no sleep at all, tremendous pain, with every ... recommend [the AVACEN 100] enough, how this has and ...
(Date:9/18/2017)... KALAMAZOO, Mich. , Sept. 18, 2017 ... , and OptiMed Specialty Pharmacy of Kalamazoo, ... offer a strategic hub service that expedites and streamlines ... personal spirometer, Spiro PD 2.0, and wellness management services.  ... is a medical device used to measure lung function ...
(Date:9/12/2017)... Sept. 12, 2017   EcoVadis , the leading platform for environmental, ... first annual edition of its Global CSR Risk and Performance Index. The ... EcoVadis, based on Scorecard Ratings that analyzed nearly 800,000 data points across ... ... ...
Breaking Medicine Technology: