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:6/26/2016)... ... ... Kasmer, a legally blind and certified personal trainer is helping to develop a weight loss ... plans to fix the two major problems leading the fitness industry today:, ... , They don’t eliminate all the reasons people quit their exercise program ...
(Date:6/25/2016)... ... June 25, 2016 , ... The temporary closing of Bruton Memorial Library on June 21 ... brings up a new, often overlooked aspect of head lice: the parasite’s ability to live ... not a common occurrence, but a necessary one in the event that lice have simply ...
(Date:6/25/2016)... ... 25, 2016 , ... Dr. Calvin Johnson has dedicated his ... implemented orthobiologic procedures as a method for treating his patients. The procedure is ... to perform the treatment. Orthobiologics are substances that orthopaedic surgeons use to help ...
(Date:6/24/2016)... , ... June 24, 2016 , ... Those who have ... these feelings, many turn to unhealthy avenues, such as drug or alcohol abuse, as ... Michigan, has released tools for healthy coping following a traumatic event. , Trauma sufferers ...
(Date:6/24/2016)... ... June 24, 2016 , ... Global law firm Greenberg Traurig, ... Elite. The attorneys chosen by their peers for this recognition are considered among the ... Traurig Shareholders received special honors as members of this year’s Legal Elite Hall of ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... June 23, 2016  MedSource announced today that ... e-clinical software solution of choice.  This latest decision ... value to their clients by offering a state-of-the-art ... relationship establishes nowEDC as the EDC platform of ... full-service clients.  "nowEDC has long been a preferred ...
(Date:6/23/2016)... Calif. , June 23, 2016 Any dentist ... many challenges of the current process. Many of them do ... of the technical difficulties and high laboratory costs involved. And ... to offer it at such a high cost that the ... it. Dr. Parsa Zadeh , founder of ...
(Date:6/23/2016)... -- In a startling report released today, National Safety Council ... comprehensive, proven plan to eliminate prescription opioid overdoses. Prescription ... are tackling the worst drug crisis in recorded U.S. history, assigned ... Kentucky , New Mexico , ... 28 failing states, three – Michigan , ...
Breaking Medicine Technology: