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:4/30/2016)... , ... April 30, 2016 ... ... CBC News on April 4th, 2016 questioned the use of the HyProCure ... EOTTS-HyProCure as “a controversial procedure.” EOTTS-HyProCure is a minimally invasive procedure performed, ...
(Date:4/29/2016)... Angeles, CA (PRWEB) , ... April 29, 2016 , ... ... Mirmelli, a mother and divorcee, shares her enthusiasm for Botox and lip injections, which ... the world famous youth oriented Coachella Valley Music and Arts Festival. The article explains ...
(Date:4/29/2016)... ... April 29, 2016 , ... On Tuesday, April 26, 2016 members of the ... signature of Gov. Nathan Deal on SB 258, the “Rural Health Care Relief” Bill. ... a 70% tax credit to individuals and corporations which donate directly to a “rural ...
(Date:4/29/2016)... ... April 29, 2016 , ... Coast Dental Fort Stewart is ... its new location in the Exchange Furniture Mall at 112 Vilseck Road in Fort ... Samsung Smart TV. Plus attendees will have the opportunity to meet general dentists Thomas ...
(Date:4/29/2016)... ... April 29, 2016 , ... ... products, announces the Gyrociser, an exercise invention which aids in proper muscle development. ... Scott Cooper, CEO and Creative Director of World Patent Marketing. "Globalization has threatened ...
Breaking Medicine News(10 mins):
(Date:4/28/2016)... -- The blood testing market in China ... and The Freedonia Group in a recent report.  The ... healthcare research firm said that China ... and in improving testing at the provincial level.   The ... Blood Testing Market in China , which utilized ...
(Date:4/28/2016)... Dr. Vivek Ahuja , ... Ste phen Schmidt ... of cloud-based software solutions for life sciences, today announced key new ... wealth of insight to a growing business.  This will bolster the ... George Phillips joined ArisGlobal in the position of Vice President ...
(Date:4/28/2016)... 28, 2016  ValGenesis, Inc., the market ... (VLMS) today announced that a prominent world ... of chronic kidney failure has selected ValGenesis ... corporate validation process. The global medical device ... to manage their validation processes electronically. Upon ...
Breaking Medicine Technology: