Navigation Links
Males Lifespan Shortened By Elevated Levels Of Testosterone

According to a new research, men who have elevated levels of testosterone may be successful as far as progeny is concerned but may lead shorter lives// when compared with men who secrete normal level of the hormone.

According to, comparative studies have studied testosterone levels and related them to mating systems and aggression, but very few studies have attempted to relate testosterone to fitness, that is, the combination of lifetime reproductive success and survival, in the wild or experimentally. Over nine breeding seasons, Wendy Reed (North Dakota State University) and her colleagues followed a group of dark-eyed juncos, small mountain songbirds found throughout North America. They injected males with elevated levels of testosterone and found that they had shorter lives but that they were very successful at siring more offspring ? even with females who were mated with other males.

"The surprising result was that testosterone-treated males had a higher overall fitness than control males," write the authors in a study in the May issue of American Naturalist. This led to the question of why don't juncos naturally have higher levels of testosterone? Testosterone-treated males produced more offspring, but they were smaller, and smaller offspring had lower postfledging survival. Older, more experienced females preferred to mate with older males and realized higher reproductive success when they did so. While young males treated with testosterone increased their ability to attract older females, it resulted in poor reproductive performance.

"Although testosterone increased male fitness, as measured by lifespan and number of offspring, the extended effects on offspring and female mates were generally negative and may ultimately constrain the evolution of higher testosterone levels in males," conclude the authors.


Page: 1

Related medicine news :

1. Males Show More Risky Behaviour with Alcohol
2. Impact Of Stress On Belfast Males
3. Sexually Abused Males Found Struggling In heir relations with Healthcare Providers
4. Same Genes Act Differently in Males and Females
5. Fewer Neurons in Amygdala of Autistic Males
6. Researchers Find Fewer Neurons in the Amygdala of Males with Autism
7. Males too Undergoes Hormonal Changes During Parenting: Study
8. Males Adapt To Battle With Competing Sperm
9. Sun Exposure Severe in Males
10. Cognitive Problems Occur More Rapidly in Female Alcoholics Than in Males
11. Female Ducks Develop Complicated Genitals to Outwit Aggressive Males
Post Your Comments:

(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)... ... June 25, 2016 , ... First Choice Emergency Room , ... Sesan Ogunleye, as the Medical Director of its new Mesquite-Samuell Farm facility. , ... our new Mesquite location,” said Dr. James M. Muzzarelli, Executive Medical Director of First ...
(Date:6/24/2016)... ... June 24, 2016 , ... A recent article published ... unfamiliar with. The article goes on to state that individuals are now more comfortable ... less common operations such as calf and cheek reduction. The Los Angeles area medical ...
(Date:6/24/2016)... ... June 24, 2016 , ... Global law firm Greenberg Traurig, P.A. announced that ... chosen by their peers for this recognition are considered among the top 2 percent ... special honors as members of this year’s Legal Elite Hall of Fame: Miami ...
(Date:6/24/2016)... ... June 24, 2016 , ... EB Medicine presented its first-ever ... Medicine conference in Ponte Vedra Beach, FL. The awards honor the outstanding work ... Practice and Pediatric Emergency Medicine Practice. , “With this award, we recognize ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016  Consumers have taken ... regulators/payers have placed more emphasis on patient outcomes. ... support programs in the pharmaceutical industry have evolved ... Consequently, pharmaceutical companies are focusing on becoming more ... providing products and services that improve health. ...
(Date:6/24/2016)... 24, 2016  Global Blood Therapeutics, Inc. (GBT) (NASDAQ: ... novel therapeutics for the treatment of grievous blood-based ... closing of its previously announced underwritten public offering ... public offering price of $18.75 per share. All ... by GBT. GBT estimates net proceeds from the ...
(Date:6/24/2016)... Dublin - ... " Global Markets for Spectroscopy Equipment" report ... This report focuses on the global market of ... applications in various applications. The report deals with spectroscopy ... industries: pharmaceutical and biotechnology, food and beverage, and environmental ...
Breaking Medicine Technology: