A group of giraffes feed on leaves from the treetops. Right now, the giraffes are not eating; the sun has gone down, leaving the grassland in darkness. What is happening
to the carbon in the trees and in the giraffes? Is carbon moving into the living things,
moving out of the living things, or both?
a) Carbon is moving into and out of the living things at the same time.
b) Carbon is only moving into the living things; it is not moving out of them.
c) Carbon is only moving out of the living things; it is not moving into them.
d) none of the above

Humans are believed to have evolved in coastal regions in east africa. the region had an abundant supply of fish for early humanoids to eat. when scientists analyze the fads gene they see an interesting pattern. people whose families have lived in this area of east africa for generation show a high level of diversity in alleles for the fads gene. conversely, people whose families had migrated inland a moderate distance from sources of fish showed a much lower diversity for fads gene alleles. additionally, the fads alleles found in people whose family has lived inland for generation are almost all gene alleles which produce fads proteins with a high level of function and activity. how do anthropologists explain this?