Navigation Links
Wild chimpanzees appear not to regularly experience menopause
Date:12/13/2007

CAMBRIDGE, Mass. -- A pioneering study of wild chimpanzees has found that these close human relatives do not routinely experience menopause, rebutting previous studies of captive individuals which had postulated that female chimpanzees reach reproductive senescence at 35 to 40 years of age.

Together with recent data from wild gorillas and orangutans, the finding -- described this week in the journal Current Biology -- suggests that human females are rare or even unique among primates in experiencing a lengthy post-reproductive lifespan.

"We find no evidence that menopause is common among wild chimpanzee populations," says lead author Melissa Emery Thompson, a postdoctoral researcher in anthropology at Harvard University. "While some female chimpanzees do technically outlive their fertility, it's not at all uncommon for individuals in their 40s and 50s -- quite elderly for wild chimpanzees -- to remain reproductively active."

While wild chimpanzees and humans both experience fertility declines starting in the fourth decade of life, most other human organ systems can remain healthy and functional for many years longer, far outstripping the longevity of the reproductive system and giving many women several decades of post-reproductive life.

By contrast, in chimpanzees reproductive declines occur in tandem with overall mortality. A chimpanzee's life expectancy at birth is only 15 years, and just 7 percent of individuals live to age 40. But females who do reach such advanced ages tend to remain fertile to the end, Emery Thompson and her colleagues found, with 47 percent giving birth once after age 40, including 12 percent observed to give birth twice after age 40.

"Fertility in chimpanzees declines at a similar pace to the decline in survival probability, whereas human reproduction nearly ceases at a time when mortality is still very low," the researchers write in Current Biology. "This suggests that reproductive senescence in chimpanzees, unlike in humans, is consistent with the somatic aging process."

In other words, human evolution has resulted in an extended life span without complementary extended reproduction.

"Why hasn't reproduction kept pace with the general increase in human longevity" It may be because there hasn't been anything for natural selection to act on, though there is heritable variation in age of menopause," Emery Thompson says. "However, it may be that the advantage older females gain by assisting their grandchildren outstrips any advantage they might get by reproducing themselves."

The oldest known wild chimpanzee, who died earlier this year at approximately age 63, gave birth to her last offspring just eight years ago, at about 55. Female chimpanzees only give birth every 6 to 8 years, on average, and they generally begin reproducing at age 13 to 15. This makes the chimpanzee reproductive profile much longer and flatter than that of humans, whose procreation is concentrated from age 25 to 35.

Emery Thompson and her colleagues gathered data from six wild chimpanzee populations in Tanzania, Uganda, Guinea, and Gambia. They compared these chimpanzees' fertility patterns to those seen among two well-studied human foraging populations, in Botswana and Paraguay.


'/>"/>

Contact: Steve Bradt
steve_bradt@harvard.edu
617-496-8070
Harvard University
Source:Eurekalert

Related biology news :

1. Fair play in chimpanzees
2. Risk of common vaginal infection linked to preterm birth appears higher for blacks
3. Scientists identify embryonic stem cells by appearance alone
4. Laser can spot illness before symptoms appear
5. Humans appear hardwired to learn by over-imitation
6. Family conditions may affect when girls experience puberty
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/4/2017)... BLOOMINGTON, Ill. , Oct. 4, 2017  GCE Solutions, a ... powerful new data and document anonymization solution on October 4, 2017. ... the pharmaceutical field to comply with policy 0070 of the European ... documents and data. ... Innovation by GCE Solutions ...
(Date:6/30/2017)... , June 30, 2017 Today, ... developer and supplier of face and eye tracking ... Featured Product provider program. "Artificial ... innovative way to monitor a driver,s attentiveness levels ... from being able to detect fatigue and prevent ...
(Date:5/16/2017)... May 16, 2017  Veratad Technologies, LLC ( www.veratad.com ... age and identity verification solutions, announced today they will ... 2017, May 15 thru May 17, 2017, in ... International Trade Center. Identity impacts the ... in today,s quickly evolving digital world, defining identity is ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... , ... October 12, 2017 ... ... announces publication of a United States multicenter, prospective clinical study that demonstrates ... point-of-care diagnostic test capable of identifying clinically significant acute bacterial and viral ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... launched Rosalind™, the first-ever genomics analysis platform specifically designed for life science ... in honor of pioneering researcher Rosalind Franklin, who made a major contribution ...
(Date:10/11/2017)... (PRWEB) , ... October 11, 2017 , ... Personal eye wash is a basic first ... eye at a time. So which eye do you rinse first if a dangerous substance ... Plum Duo Eye Wash with its unique dual eye piece. , “Whether its ...
(Date:10/11/2017)... BioMarketing, a leading provider of patient support solutions, has announced ... network, which will launch this week. The VMS CNEs will ... to enhance the patient care experience by delivering peer-to-peer education ... professionals to help women who have been diagnosed and are ... ...
Breaking Biology Technology: