Featured Research

from universities, journals, and other organizations

Mice Living In Sandy Hills Quickly Evolved Lighter Coloration

Date:
September 2, 2009
Source:
Harvard University
Summary:
In a vivid illustration of natural selection at work, scientists have found that deer mice living in Nebraska's Sand Hills quickly evolved lighter coloration after glaciers deposited sand dunes atop what had been much darker soil.

As the result of natural selection for crypsis, deer mice (Peromyscus maniculatus) living on the pale soils of the Nebraska Sand Hills are lighter (top) than deer mice from darker, surrounding areas (bottom). Mice are shown on contrasting soil backgrounds (bottom: Sand Hills soil; top: soil from outside the Sand Hills).
Credit: Photos by Emily Kay

In a vivid illustration of natural selection at work, scientists at Harvard University have found that deer mice living in Nebraska's Sand Hills quickly evolved lighter coloration after glaciers deposited sand dunes atop what had been much darker soil. The work is described this week in the journal Science.

Related Articles


Co-authors Catherine R. Linnen and Hopi E. Hoekstra show that the different variants of a single gene determines whether a deer mouse is dark or pale -- a small difference with huge survival implications for a species widely hunted by owls, hawks and other visual predators.

"Our work shows that rapid adaptive change, such as the evolution of lighter coloration among Sand Hills mice, need not always rely on pre-existing genetic variation," says Linnen, a postdoctoral researcher in Harvard's Department of Organismic and Evolutionary Biology. "We show that a single genetic change creates lighter coloration in these mice, and that this variant clearly arose recently, sometime after the formation of the Sand Hills."

The species Linnen and Hoekstra studied, Peromyscus maniculatus, is the most widespread mammal in North America. By analyzing the strength of natural selection in favor of lighter Sand Hills mice, the scientists determined that predation would drive virtually all individuals in the area toward pale coloration within 8,000 years -- just slightly less than the age of the Sand Hills.

This and other evidence, including much greater genetic uniformity among pale mutants than their dark wildtype cousins, suggests this mutation is a relatively recent development, likely arising shortly after the formation of the Sand Hills in north-central Nebraska.

Linnen and Hoekstra found that light coloration arises from increased activity in a single gene, called Agouti. This increased expression, in turn, is associated with the deletion of a single amino acid, a process that appears to be under natural selection. This Agouti mutation generates wider pale bands on dorsal hairs, making the entire animal appear golden rather than brown.

"This work sheds new light on the forces affecting diversity in nature," says Hoekstra, John L. Loeb Associate Professor of the Natural Sciences in Harvard's Faculty of Arts and Sciences. "It's an exciting time in biology, with the integration of field studies, genetic analysis, and developmental and molecular biology enabling us to connect genes and molecular mechanisms with species' traits in the wild. In the bicentennial of Charles Darwin's birth and on the 150th anniversary of his publication of On the Origin of Species, this study vividly illustrates the power of natural selection."

The Sand Hills, rolling dunes occupying more than a quarter of Nebraska's area, were created by glacial deposition of sand sometime in the last 10,000 years. Since the soils of these hills are composed mostly of light-colored quartz grains, pale mice are better camouflaged against owls and other raptors. Surrounding areas, with much darker soils, tend to be occupied by dark brown mice.

By mating light Sand Hills mice and dark mice found outside the Sand Hills, Linnen and Hoekstra determined that the light coloration seen in Agouti mutants is genetically dominant to the darker coats seen among wildtype mice.

Linnen and Hoekstra's co-authors are Evan P. Kingsley of Harvard's Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology and Jeffrey D. Jensen of the University of California, Berkeley. Their work was funded by the National Institutes of Health, National Science Foundation, and Harvard's Museum of Comparative Zoology.


Story Source:

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


Cite This Page:

Harvard University. "Mice Living In Sandy Hills Quickly Evolved Lighter Coloration." ScienceDaily. ScienceDaily, 2 September 2009. <www.sciencedaily.com/releases/2009/08/090827141342.htm>.
Harvard University. (2009, September 2). Mice Living In Sandy Hills Quickly Evolved Lighter Coloration. ScienceDaily. Retrieved January 29, 2015 from www.sciencedaily.com/releases/2009/08/090827141342.htm
Harvard University. "Mice Living In Sandy Hills Quickly Evolved Lighter Coloration." ScienceDaily. www.sciencedaily.com/releases/2009/08/090827141342.htm (accessed January 29, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Brawling Pandas Are Violently Adorable

Brawling Pandas Are Violently Adorable

Buzz60 (Jan. 29, 2015) Video of pandas play fighting at the Chengdu Research Base in China will make your day. Mara Montalbano (@maramontalbano) shows us. Video provided by Buzz60
Powered by NewsLook.com
Why Researchers Say We Should Cut Back On Biofuels

Why Researchers Say We Should Cut Back On Biofuels

Newsy (Jan. 29, 2015) Biofuels aren&apos;t the best alternative to fossil fuels, according to a new report. In fact, they&apos;re quite a bad one. Video provided by Newsy
Powered by NewsLook.com
3-D Printed Wheelchair Helps Two-Legged Dog Learn to Run

3-D Printed Wheelchair Helps Two-Legged Dog Learn to Run

Buzz60 (Jan. 29, 2015) 3-D printing helps another two-legged dog run around with his four-legged friends. Jen Markham (@jenmarkham) has the adorable video. Video provided by Buzz60
Powered by NewsLook.com
Dogs Bring on So Many Different Emotions in Their Human Best Friends

Dogs Bring on So Many Different Emotions in Their Human Best Friends

RightThisMinute (Jan. 28, 2015) From new-puppy happy tears to helpful-grocery-carrying-dog laughter, our four-legged best friends can make us feel the entire spectrum of emotions. Video provided by RightThisMinute
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