Human physical activities differ significantly from other species. How, when and why did these capabilities evolve? What adaptations underlie them? And how did the evolution of human physical activity affect other key human characteristics that have advanced our species? Yana Kamberov explores how sweating evolved and what it means for Homo sapiens. Humans use sweating as the primary mechanism to dump body heat. Humans' ability to effectively harness sweating as a thermoregulatory mechanism is a product of the evolution of a massively increased sweat gland density and a drastic reduction in the size of body hair. Advances have been made in identifying the genetic basis for how these unique and essential adaptations of human physiology evolved. (#36949)