Navigation Links
Females decide whether ambitious males float or flounder

Hamilton, ON. January 30, 2007 Aggression, testosterone and nepotism dont necessarily help one climb the social ladder, but the support of a good female can, according to new research on the social habits of an unusual African species of fish.

The study, published today in the journal Proceedings of the Royal Society, highlights the complex relationship between social status, reproductive physiology and group dynamics.

We found that changes in social status were regulated by the most dominant female in a social group, says John Fitzpatrick, lead researcher and a graduate student in the department of Biology at McMaster University. In fact, dominant females seemed to act as gatekeepers, allowing only males larger than themselves to move up in status and become dominant.

Males rising to a dominant social position, says Fitzpatrick, instantly altered their behaviour, becoming more aggressive. In addition, they dramatically ramped up their reproductive physiology, almost doubling the size of their testes in one week.

Working underwater off the Zambian shores of Lake Tanganyika in Africa, the researchers examined how males respond to changes in social position in the cichlid fish, Neolamprologus pulcher. This species lives in permanent social groups made up of a dominant male and female breeding pair and subordinate males and females that help this pair look after young and defend territory.

By removing the male breeders, researchers created vacancies and provided an opportunity for subordinate males to rise through the ranks.

Hormones and genetic relationships didnt necessarily determine who gets to be top dog, says Sigal Balshine, the senior author on the study and an associate professor in the department of Psychology, Neuroscience & Behaviour. Most folks would have thought that how aggressive you are, how big and powerful you are or how much testosterone you have might be important in understanding status change and dominance rankings. Our study combined several approaches to show that simply isnt the case instead, the female and the social landscape are key.


Contact: Michelle Donovan
McMaster University

Related medicine news :

1. Researchers discover correlation between GERD and obesity in females
2. Females avoid incest by causing male relatives to leave home
3. The Polls are Open! America Votes to Decide Which Hospital is the Most Deserving of Siemens Newest MRI Technology
4. American Cancer Society Seeks Volunteers to Help Decide Who Gets Research Grants
5. Study reveals how stem cells decide to become either skeletal or smooth muscle
6. MedQuist Evaluating Whether a Sale of the Company is in the Best Interests of the Company and its Shareholders
7. Study fuels debate over whether exercise and body size influence ovarian cancer risk
8. Doctors and Medical Ethicist Discuss Whether Doctors Should Participate in Capital Punishment
9. Doctors and medical ethicist discuss whether doctors should participate in capital punishment
10. New upper limit defined for normal ALT in adolescent males
11. Floating effective for stress and pain
Post Your Comments:
(Date:11/30/2015)... ... November 30, 2015 , ... RoamRight, a leading provider ... with Public Television’s Travel With Kids to promote family vacations around the ... as they explore international destinations and educate families about the people and places of ...
(Date:11/30/2015)... ... November 30, 2015 , ... Advocare Orthopedic ... orthopedic care. Led by John Vitolo, M.D., the center offers their patients ... team at Advocare Orthopedic & Sports Medicine is ready to help their patients ...
(Date:11/30/2015)... Pittsburgh, PA (PRWEB) , ... November 30, 2015 ... ... according to a new study by UPMC and KingMed Diagnostics ... UPMC over three years found that consultation with UPMC pathologists resulted in significantly ...
(Date:11/30/2015)... ... ... The American Society for Clinical Pathology (ASCP) announced today that it has ... 30, ASCP shared its “Give a minute. Get tested. Find a cure.” icon and ... getting tested for HIV. , ASCP has asked members to replace their Facebook, Twitter, ...
(Date:11/30/2015)... ... November 30, 2015 , ... An inventor from Charlottesville, ... the womb. "My last baby had high blood pressure due to loud noises," she ... protect their babies from noise pollution as well as radio waves and microwaves." , ...
Breaking Medicine News(10 mins):
(Date:11/30/2015)... BOSTON , Nov. 30, 2015  Kevin ... of Sensium Healthcare, a global pioneer in wireless ... Boston, MA , Mr. Smith ... of Sensium,s global commercial strategy.  He will also ... universities, to build clinical evidence for SensiumVitals, the ...
(Date:11/30/2015)... , Nov. 30, 2015  The fee-for-service ... in U.S. medical imaging is on its ... accountable care payer-provider contracts are set to ... their wake, alter provider-vendor relationships. The shift ... push forward new purchasing frameworks in the ...
(Date:11/30/2015)... WOODCLIFF LAKE, N.J. and SAN ... Inc. and Arena Pharmaceuticals, Inc. (NASDAQ: ARNA ) ... (FDA) has accepted for filing the New Drug Application ... approved, the extended release formulation will offer patients a ... ® ) is currently approved as ...
Breaking Medicine Technology: