Featured Research

from universities, journals, and other organizations

Genetic Differences Influence Aging Rates In The Wild

Date:
December 16, 2007
Source:
Cell Press
Summary:
Long-lived, wild animals harbor genetic differences that influence how quickly they begin to show their age, according to the results of a long-term study. Evidence for the existence of such genetic variation for aging rates -- a central tenet in the evolutionary theory that explains why animals would show physiological declines as they grow older -- had largely been lacking in natural populations until now, the researchers said.

Long-lived, wild animals harbor genetic differences that influence how quickly they begin to show their age, according to the results of a long-term study. Evidence for the existence of such genetic variation for aging rates--a central tenet in the evolutionary theory that explains why animals would show physiological declines as they grow older--had largely been lacking in natural populations until now, the researchers said.

Related Articles


"We've found that individuals differ in their rates of aging, or senescence, and that these differences are (at least in part) caused by genetic effects so they will be inherited," said Alastair Wilson of the University of Edinburgh. "While the genetic effects we found are completely consistent with existing theory, scientists hadn't previously managed to test this theory properly except in controlled laboratory experiments.

"We've also done this work on long-lived mammals," he added. "For someone interested in the evolution of aging and senescence in humans, these are going to be more relevant organisms than Drosophila [fruit flies]."

Scientists normally expect genetic mutations having bad effects to be removed by natural selection, Wilson explained. Conversely, selection will lead to an increase in the frequency of mutations that are beneficial. "On this basis, any genes with bad effects on survival or reproduction should be removed by selection," he said. "But if that were true then there is no reason for individuals to deteriorate as they get old."

Aging therefore raises a critical question: How has natural selection failed to remove genetic effects responsible for such reduced fitness among older individuals" Current evolutionary theory explains this phenomenon by showing that, as a result of the risk of death from environmental causes that individuals experience over the course of their lives, the force of selection inevitably weakens with age, he continued. This, in turn, means that genetic mutations having detrimental effects that are only felt late in life may persist in a population. Although widely accepted, this theory rests on the assumption that there is genetic variation for aging in natural systems.

To look for such genetic variation in the new study, the researchers examined wild Soay sheep and red deer living on two Scottish islands. Those populations were ideal for the study because they provide unparalleled levels of data, including individual survival and reproductive success, for large numbers of long-lived animals, Wilson said. In both study systems, individually marked animals are followed throughout their lives from birth until death, and their relationships to one another are known.

In both the red deer and sheep populations, they found evidence for age-specific genetic effects on "fitness"--a measure combining the animals' probability of survival and reproduction. "The present study provides, to our knowledge, the first evidence for additive genetic variance in aging rates from a wild, non-model study organism," the researchers concluded. "Furthermore, the age-specific patterns of additive genetic (co)variation evident in the two populations examined here were entirely consistent with the hypothesis that declines in fitness with age are driven by a weakening of natural selection."

This research is reported online on December 13th in Current Biology.

The researchers include Alastair J. Wilson, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK; Daniel H. Nussey, Department of Zoology, University of Cambridge, Cambridge, UK; Josephine M. Pemberton, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK; Jill G. Pilkington, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK; Alison Morris, Department of Zoology, University of Cambridge, Cambridge, UK; Fanie Pelletier, Division of Biology and the National Environment, Research Council Centre for Population Biology, Imperial College, London, UK; Timothy H. Clutton-Brock, Department of Zoology, University of Cambridge, Cambridge, UK; and Loeske E.B. Kruuk, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Cite This Page:

Cell Press. "Genetic Differences Influence Aging Rates In The Wild." ScienceDaily. ScienceDaily, 16 December 2007. <www.sciencedaily.com/releases/2007/12/071212201351.htm>.
Cell Press. (2007, December 16). Genetic Differences Influence Aging Rates In The Wild. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2007/12/071212201351.htm
Cell Press. "Genetic Differences Influence Aging Rates In The Wild." ScienceDaily. www.sciencedaily.com/releases/2007/12/071212201351.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins