BIOL 1209 Chapter : Writing Assignment 2
Document Summary
In recent years the polar bear population has been slowly decreasing due to rising temperatures, melting the ice caps. Polar bears (ursus maritimus) are only found in the arctic and are generally distributed in a circumpolar region. Today out of the 19 sub-populations of polar bears inhabiting this area, 7 are in decline. Due to raising temperatures, the sea ice that provide the bears with living space, hunting grounds, and dens are disappearing (richter n. p). The decline of sea ice directly affects reproductive rates of polar bears because the male polar bears use the ice caps to follow the scent of female tracts. In september 2011 sea ice levels were the second lowest in history since 1978 (richtner n. p). This decline in ice has dramatically lowered the polar bear population. Sudden reduction in the polar bear population may lead to fixation in one or more traits through genetic drift.
