Chapter 19

A lamprey, a shark, a lizard, and a rabbit share all the following characteristics except a. pharyngeal slits in the embryo or adult. b. vertebrae, c. hinged jaws. d. a dorsal, hollow nerve cord.

Why were the Tiktaalik fossils an exciting discovery for scientists studying tetrapod evolution? a. They are the earliest frog-like animal discovered to date. b. They show that tetrapods successfully colonized land much earlier than previously thought. c. They have a roughly equal combination of fishlike and tetrapod-like characteristics. d. They demonstrate conclusively that limbs evolved as lobe-fins dragged themselves from pond to pond during droughts.

Fossils suggest that the first major trait distinguishing hominins from other primates was a. a larger brain. b. erect posture. c. forward-facing eyes with depth perception. d. tool making.

Which of these is not a member of the anthropoids? a. chimpanzee b. tarsier c. human d. New World monkey

Studies of DNA support which of the following? a. Members of the group called australopiths were the first to migrate from Africa. b. Homo sapiens originated in Africa. c. Sahelanthropus was the earliest hominin. d. Chimpanzees are more similar to gorillas and orangutans than to humans.

The earliest members of the genus Homo a. had a larger brain compared to other hominins. b. probably hunted dinosaurs. c. lived about 4 million years ago. d. were the first hominins to be bipedal.

Birds and mammals are both endothermic, and both have four-chambered hearts. Most reptiles are ectothermic and have three-chambered hearts. Why don't biologists group birds with mammals? Why do most biologists now consider birds to be reptiles?

What adaptations inherited from our primate ancestors enable humans to make and use tools?

Summarize the hypotheses that explain variation in human skin color as adaptations to variation in UV radiation.

Explain some of the reasons why the human species has been able to expand in number and distribution to a greater extent than most other animals.