Environmental cues control reproductive timing and longevity

Jun 25, 2009

When humans and animals delay reproduction because food or other resources are scarce, they may live longer to increase the impact of reproduction, according to a new study by University of Minnesota researchers published in the June 25 issue of PLoS (Public Library of Science) One.

The discovery, which explains why starvation can lead to longer life, has important implications for improving human health and lengthening .

The basic premise is that individuals use environmental cues to predict population declines, causing them to delay reproduction until the decline has occurred, when each offspring will make a bigger contribution to the gene pool. Conversely, if bad times turn to good times and the population is on the verge of a boom, reproducing sooner rather than later will help their genes thrive.

"If the population is decreasing, future kids make a bigger splash in the gene pool than current kids," explains Will Ratcliff, a College of Biological Sciences graduate student who came up with the idea for the study. "So, if there are tradeoffs between current and future reproduction, delaying reproduction can be a good idea, even if it reduces the number of kids you have during your lifetime."

Fluctuations in testosterone levels provide an example of how the environment and organisms interact to guide reproduction, explains R. Ford Denison, adjunct professor in the College of Biological Sciences and Ratcliff's adviser. suppresses the immune system. So when trigger high levels, reproduction is high but longevity drops.

also control the age of menarche. In African countries with chronic food shortages, girls experience menarche much later than in the U.S., where rich diets trigger early menarche. Food scarcity is a signal that population is likely to decline, so reproduction is delayed, while an abundance of rich food signals an increase, causing reproductive age to drop.

"Our hypothesis may explain hormesis, the mysterious health benefits of low doses of toxins - including those that plants like broccoli make to defend themselves from insects," says Denison. " When their usual foods are scarce, organisms turn to plants containing chemicals that can suppress and consequently increase longevity "These toxins may be abundant in 'famine foods' that are eaten only when meat and fruit are not available" Denison adds.

Source: University of Minnesota (news : web)

Explore further: Poachers threaten new slaughter of South African elephants

add to favorites email to friend print save as pdf

Related Stories

Old flies can become young moms

Nov 24, 2008

Female flies can turn back the biological clock and extend their lifespan at the same time, University of Southern California biologists report.

Simplest known animals engage in sex

Oct 10, 2005

A Yale University study suggests even the most simple of animals engage in sex. Ana Signorovitch and colleagues have demonstrated placozoans, the simplest known free-living animals, undergo a sexual phase in their life cycle.

Researchers at Illinois explore queen bee longevity

May 08, 2007

The queen honey bee is genetically identical to the workers in her hive, but she lives 10 times longer and – unlike her sterile sisters – remains reproductively viable throughout life. A study from the ...

Recommended for you

Japan wraps up Pacific whale hunt

15 hours ago

Japan announced Tuesday that it had wrapped up a whale hunt in the Pacific, the second campaign since the UN's top court ordered Tokyo to halt a separate slaughter in the Antarctic.

Algae under threat from invasive fish

16 hours ago

Tropical fish invading temperate waters warmed as a result of climate change are overgrazing algae, posing a threat to biodiversity and some marine-based industries.

User comments : 0