Featured Research

from universities, journals, and other organizations

Key To Evolutionary Fitness: Cut The Calories

Date:
July 2, 2009
Source:
Society for Experimental Biology
Summary:
Charles Darwin postulated that animals eat as much as possible while food is plentiful, and produce as many offspring as this would allow. However, new research shows that, even when food is abundant, intake reaches a limit. One theory for this is that animals actively limit their energy turnover to maintain a higher level of reproductive success over their lifetime.

Charles Darwin and his contemporaries postulated that food consumption in birds and mammals was limited by resource levels, that is, animals would eat as much as they could while food was plentiful and produce as many offspring as this would allow them to.

However, recent research has shown that, even when food is abundant, energy intake reaches a limit, even in animals with high nutrient demands, such as lactating females. Scientists at the Research Institute of Wildlife Ecology in Vienna suggest that this is due to active control of maternal investment in offspring in order to maintain long-term reproductive fitness.

The research, to be presented by Dr Teresa Valencak at the Society for Experimental Biology Annual Meeting in Glasgow has shown that, when their energy reserves are low or when their offspring are kept in cooler temperatures, Brown hares are able to increase their energy turnover and rate of milk production above that normally observed. This indicates that, ordinarily, the hares are operating at below their maximum capacity and shows that this is not due to any kind of physiological constraint, such as length of digestive tract or maximum capacity of mammary glands. Also, as the hares were provided with plentiful food, there could be no limitation of energy turnover due to food availability.

The way that females regulated their energy expenditure according to pup demand and their own fat reserves but did not exceed certain levels fitted with the group's theory that using energy at close to the maximum rate has costs for animals which may compromise their ability to successfully reproduce in the future. If a hare puts most of its energy into a litter of pups then it will have little left over for growth and body repairs for example, which may shorten its life or make it less able to produce or care for young in the future. By actively limiting the rate of energy turnover, a mother can prevent this and maintain a higher level of reproductive success over her lifetime.


Story Source:

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


Cite This Page:

Society for Experimental Biology. "Key To Evolutionary Fitness: Cut The Calories." ScienceDaily. ScienceDaily, 2 July 2009. <www.sciencedaily.com/releases/2009/07/090701082712.htm>.
Society for Experimental Biology. (2009, July 2). Key To Evolutionary Fitness: Cut The Calories. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2009/07/090701082712.htm
Society for Experimental Biology. "Key To Evolutionary Fitness: Cut The Calories." ScienceDaily. www.sciencedaily.com/releases/2009/07/090701082712.htm (accessed July 22, 2014).

Share This




More Plants & Animals News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com
A Centuries' Old British Tradition Is Far from a Swan Song

A Centuries' Old British Tradition Is Far from a Swan Song

AFP (July 19, 2014) As if it weren't enough that the Queen is the Sovereign of the UK and 15 other Commonwealth realms, she is also the owner of all Britain's unmarked swans. Duration: 02:18 Video provided by AFP
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:
from the past week

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