e360 digest


24 Jul 2012: Evolution of Polar Bear
Followed Changes in Climate, Study Says

An analysis of sequenced polar bear genomes provides new insights into how climate change and interbreeding with brown bears led to the evolution of the modern-day polar bear. In an analysis of the

Arctic Roamers: The Move of
Southern Species into Far North

Arctic Roamers: The Move of Southern Species into Far North
Grizzly bears mating with polar bears. Red foxes out-competing Arctic foxes. These, Ed Struzik writes, are just some of the worrisome phenomena now occurring as Arctic temperatures soar and the Arctic Ocean melts.
READ THE e360 REPORT
nuclear genomes of 28 brown, black, and polar bears, an international team of researchers found evidence that polar bear populations fluctuated with climate shifts over the last million years, with populations increasing during cooler periods and declining during periods of warmer temperatures. Their findings also suggest that during periods of glacial retreat, polar bears came into greater contact with brown bears as their ranges overlapped. “Maybe we’re seeing a hint that in really warm times, polar bears changed their life style and came into contact, and indeed interbred, with brown bears,” said Stephan Schuster, a scientist at Pennsylvania State University and co-lead author of the study, published in the Proceedings of the National Academy of Sciences. While earlier research indicated that polar bears have only existed for about 600,000 years, the new research suggests that the polar bear may have evolved into a distinct species 4 to 5 million years ago.


Yale
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
.

SEARCH e360



Donate to Yale Environment 360
Yale Environment 360 Newsletter

CONNECT


ABOUT

About e360
Contact
Submission Guidelines
Reprints

E360 en Español

Universia partnership
Yale Environment 360 articles are now available in Spanish and Portuguese on Universia, the online educational network.
Visit the site.


DEPARTMENTS

Opinion
Reports
Analysis
Interviews
Forums
e360 Digest
Podcasts
Video Reports

TOPICS

Biodiversity
Business & Innovation
Climate
Energy
Forests
Oceans
Policy & Politics
Pollution & Health
Science & Technology
Sustainability
Urbanization
Water

REGIONS

Antarctica and the Arctic
Africa
Asia
Australia
Central & South America
Europe
Middle East
North America

e360 SPECIAL REPORT

“Tainted
A three-part series Tainted Harvest looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup.
Read the series.

e360 MOBILE

Mobile
The latest
from Yale
Environment 360
is now available for mobile devices at e360.yale.edu/mobile.

e360 VIDEO

Warriors of Qiugang
The Warriors of Qiugang, a Yale Environment 360 video, chronicles a Chinese village’s fight against a polluting chemical plant. It was nominated for a 2011 Academy Award for Best Documentary Short.
Watch the video.


header image
Top Image: aerial view of Iceland. © Google & TerraMetrics.

e360 VIDEO

Badru's Story
Badru’s Story, winner of the Yale Environment 360 Video Contest, documents the work of African researchers monitoring wildlife in Uganda's remote Bwindi Impenetrable National Park.
Watch the video.

OF INTEREST



Yale