of the Western Arctic, Northwest Territories, Canada (excellent
resource!). Photo: Canada Parks & Tourism. are found inside
animal cells. They produce ATP -- a chemical that powers
countless body processes -- and heat. Is this heat just a
byproduct, or can it be a subject of evolution? How did people
get accustomed to living near the poles? Just take it from a
tropical person who's moved to Wisconsin: Making body heat is a
big problem. For most of human history, staying warm was not
just a matter of comfort, but of survival. Understanding the
when, where and how of this adaptation is a critical issue for
studying human migration, and now comes an answer, courtesy of
work reported this week in Science by Douglas Wallace, a
population geneticist at the University of California at Irvine.
With his colleagues, Wallace has surveyed the genetics of a
structure called the mitochondrion, which is found in all
mammalian For decades, scientists have known that this bitty
organelle creates energy, in the form of adenosi