Polar bears have evolved several adaptations for surviving in the Arctic environment. Their fur became thicker and white to camouflage in snow. Their paws enlarged to help swim and walk on ice. Their teeth sharpened for tearing seals. When ice levels decline, polar bears must range further for food and may scavenge more. Mother polar bears' rich milk provides cubs the energy for Arctic life.

1. Polar Bears Kerrie, Krystal, and Kyle

11. http://www.helium.com/items/374037-evolution-of-the-polar-bear http://www.sheeptoshawl.com/news/data/upimages/cute_polar_bear.jpg http://stateoftheart.popphoto.com/blog/images/2007/09/14/picture_3.png http://www.cksinfo.com/clipart/animals/bears/polarbears/Polar-Bear-cubs.png http://merrimerri.files.wordpress.com/2008/01/carseat.jpg http://www.solarnavigator.net/animal_kingdom/animal_images/Polar_Bear_snow_2004.jpg Picture Websites

12. Stirling, Ian. &quot;The First Polar Bears.&quot; Poalr Bears. 21-22. 16 Jan. 2009 <http://books.google.com> Science Online. Facts On File News Services. 16 Jan. 2009 <http://www.2facts.com/> &quot;Polar Bear Evolution.&quot; Polar Bears International. 2009. 16 Jan. 2009 <http://www.polarbearsinternational.org/bear-facts/polar-bear-evolution/> &quot;Determinants of Home Range Size for Polar Bears.&quot; Wiley InterScience. 1999-2009. John Wiley &Sons Inc. 16 Jan. 2009 <http://www3.interscience.wiley.com/journal/119087492/ abstract?CRETRY=1&SRETRY=0> Works Cited