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 rapists. Dr. Brennan argues that elaborate female duck anatomy evolves as a countermeasure against aggressive males. “Once they choose a male, they’re making the best possible choice, and that’s the male they want siring their offspring,” she said. “They don’t 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.

Source-Medinia
GPL/M
'"/>




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:6/26/2016)... (PRWEB) , ... June 26, 2016 , ... ... fertility once they have been diagnosed with endometriosis. These women need a treatment ... also require a comprehensive approach that can help for preservation of fertility and ...
(Date:6/25/2016)... TX (PRWEB) , ... June 25, 2016 , ... Austin ... of the American College of Mohs Surgery and to Dr. Russell Peckham for medical ... and highly effective treatment for skin cancer. The selective fellowship in Mohs Micrographic Surgery ...
(Date:6/25/2016)... Aliso Viejo, California (PRWEB) , ... June 25, 2016 , ... ... preset to fit their specific project," said Christina Austin - CEO of Pixel Film ... all fully customizable and all within Final Cut Pro X . Simply select ...
(Date:6/25/2016)... ... June 25, 2016 , ... As a lifelong Southern Californian, ... and his M.D from the David Geffen School of Medicine at UCLA. He trained ... Angeles to complete his fellowship in hematology/oncology at the UCLA-Olive View-Cedars Sinai program where ...
(Date:6/25/2016)... ... June 25, 2016 , ... On Friday, June 10, Van Mitchell, Secretary of ... award to iHire in recognition of their exemplary accomplishments in worksite health promotion. , ... Workplace Health & Wellness Symposium at the BWI Marriott in Linthicum Heights. iHire was ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... Ontario , June 27, 2016  VMS Rehab ... Company,s Board will take whatever measures required to build ... Company,s stock which is currently listed on the OTC ... Wexler, Company Chairman and CEO, "We are seeing an ... difficult to understand, not only by the Company, but ...
(Date:6/24/2016)... June 24, 2016   Bay Area Lyme ... Dean Center for Tick Borne Illness , ... Rehabilitation, MIT Hacking Medicine, University of California, Berkeley, ... announced the five finalists of Lyme Innovation ... More than 100 scientists, clinicians, researchers, entrepreneurs, and ...
(Date:6/24/2016)... CLEMENTE, Calif. , June 24, 2016  American Respiratory Labs ... company, is now able to perform sophisticated lung assessments in patients, ... Technologies , Inc. Patients are no longer limited ... ndd,s EasyOne PRO ® , ARL patients like Jeanne R. of ... done in the comfort of her own home. ...
Breaking Medicine Technology: