section_path: Anatomical changes/Other changes
section_name: Other changes
paragraph_text: Other changes
  
  A number of other changes have also characterized the evolution of humans, among them an increased reliance on vision rather than smell (highly reduced olfactory bulb); a longer juvenile developmental period and higher infant dependency; a smaller gut and small, misaligned teeth; faster basal metabolism; loss of body hair; an increase in eccrine sweat gland density that is ten times higher than any other catarrhinian primates, yet humans use 30% to 50% less water per day compared to chimps and gorillas; more REM sleep but less sleep in total; a change in the shape of the dental arcade from u-shaped to parabolic; development of a chin (found in Homo sapiens alone); styloid processes; and a descended larynx. As the human hand and arms adapted to the making of tools and were used less for climbing, the shoulder blades changed too. As a side effect, it allowed human ancestors to throw objects with greater force, speed and accuracy.