Which researcher's scientific approach to the origin of humans, by searching for fossils to test his hypothesis rather than using comparative animal anatomy, create the discipline of paleoanthropology?

a. dubois
b. darwin
c. haeckel
d. huxley

Which environmental change allowed people to travel by land between asia and north america a.human apaption to arctic environments b.the introduction to horses to north america c.the formation of ice sheets on land d.a rise in ocean temperatures