Thalidomide, now banned for use as a sedative during pregnancy, was used in the early 1960s by many women in their first trimester of pregnancy. Some of these women gave birth to children with limb and organ deformities, suggesting that the drug most likely influenced ________.

#Question id: 4975

#Unit 11. Evolution and Behavior

The observation that tusks were limited to males in several species, and were apparently not used in food-gathering, is evidence that the tusks probably

#Question id: 4976

#Unit 11. Evolution and Behavior

Which of these is the most likely explanation for the existence of dicynodont fossils on modern-day Antarctica?

#Question id: 4977

#Unit 11. Evolution and Behavior

There are at least a dozen known species in the extinct genus Lystrosaurus. If each species was suited to a quite different environment, then this relatively large number of species is likely due to

#Question id: 5011

#Unit 11. Evolution and Behavior

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of

#Question id: 5010

#Unit 11. Evolution and Behavior

Which of the following steps has not yet been accomplished by scientists studying the origin of life? 

#Question id: 5009

#Unit 11. Evolution and Behavior

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped to make possible the evolution of the tetrapod limb. This type of change is illustrative of