Which of the following aided the expansion of human populations throughout North America?
A. the invention of the wheel
B. abundant big-game animals
C. the domestication of primitive horses
D. widespread slash-and-burn horticulture
E. raised-field cultivation
Question 2
Although there is now evidence that several human groups colonized the Americas, possibly using different routes, those that crossed over through Beringia to reach the Americas did so
A. because they were fleeing from warlike Cro-Magnon groups.
B. in order to take advantage of large flint deposits in South America.
C. following herds of big-game animals (woolly mammoths, especially).
D. because they were gradually forced into new territories by the expansion of more advanced agricultural groups in Asia.
E. in their search for colder climates, because these Neandertals were adapted to cold weather.
Photograph of the flea that transmits Yersinia pestis to cause bubonic plague, called the oriental r
Lateral View of the human brain in cross section
human skin and pressure points
West facade, Cha1134–1220; south spire, ca. 1160; north spire 1507–13.
Human karyotype
Human beta-globin–complex locus control region