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:4/3/2017)... April 3, 2017  Data captured by ... platform, detected a statistically significant association between ... to treatment and objective response of cancer ... to predict whether cancer patients will respond ... as well as to improve both pre-infusion potency ...
(Date:3/28/2017)... March 28, 2017 The report ... (Camera, Monitors, Servers, Storage Devices), Software (Video Analytics, VMS), ... - Global Forecast to 2022", published by MarketsandMarkets, the ... and is projected to reach USD 75.64 Billion by ... 2022. The base year considered for the study is ...
(Date:3/23/2017)... Mar. 23, 2017 Research and Markets has ... Analysis & Trends - Industry Forecast to 2025" report to ... ... a CAGR of around 8.8% over the next decade to reach ... analyzes the market estimates and forecasts for all the given segments ...
Breaking Biology News(10 mins):
(Date:4/19/2017)... and PUNE, India , April 19, 2017 /PRNewswire/ ... "Membrane Microfiltration Market: Global Opportunity Analysis and Industry Forecast, 2014-2022 ," the global ... $12,858 million by 2022, registering a CAGR of 9.6% from 2016 to 2022. ... ... ...
(Date:4/19/2017)... and WESTMINSTER, Colo. ... LLC ("Oxford"), an industry-leading specialty finance firm that ... services companies, today announced the closing of a ... Inc. ("Cerapedics") a privately-held orthobiologics company engaged in ... products for the treatment of orthopedic injuries. ...
(Date:4/19/2017)... , April 19, 2017   Thermo Fisher ... the multi-center Procalcitonin MOnitoring SEpsis (MOSES) Study have ... of Critical Care Medicine . Researchers from ... Severe Sepsis Patients: Results From the Multicenter Procalcitonin ... the B·R·A·H·M·S PCT (procalcitonin) assay to assess risk ...
(Date:4/18/2017)... ... April 18, 2017 , ... CallTower, an industry-leading ... Solution Provider. , Channel Partners program recognizes IT and telecom channel leaders who ... advocacy of the channel during transition and convergence. CallTower is the first provider ...
Breaking Biology Technology: