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Figure 20.1   If Figure 20.1 is an accurate depiction of relatedness, then which of the following should be correct?   1. The entire tree is based on maximum parsimony. 2. If all species depicted here make up a taxon, this taxon is monophyletic. 3. The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E. 4. Species A is the direct ancestor of both species B and species C. 5. The species present at position 3 is ancestral to C, D, and E.

On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island’s lowlands and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species’ nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago.   The observation that island D. yakuba are more closely related to mainland D. yakuba than island D. yakuba are to D. santomea is best explained by proposing that D. santomea

A patient is diagnosed with a continuous headache syndrome. What treatment should the nurse expect to be prescribed for this patient?

DDT was once considered a “silver bullet” that would permanently eradicate insect pests. Instead, today DDT is largely useless against many insects. Which of the following should have occurred for this pest eradication effort to be successful in the long run?

Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales’ closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged (see Figure 20.5)   Figure 20.5   One morphological feature of modern cetaceans is a vestigial pelvic girdle. If it is determined that cetacean lineage diverged from the artiodactyls’ lineage after the divergence of pigs and other artiodactyla, then what should be true of the vestigial pelvic girdle of cetaceans?

A patient recovering from a hysterectomy does not want to take the prescribed estrogen replacement therapy because of the fear of developing breast cancer. Which response by the nurse is the most appropriate?

When attempting to provide health-care services to the homeless, which would be a realistic concern for a nurse?

“Conventional wisdom holds that the development of separate species happens quickly, most often when populations become separated by a geographical barrier.” This is called ________ speciation. “Even if these groups meet again and manage to mate before diverging too far from one another, their offspring will be unfit and die out.” This is described as hybrid ________.

The nurse is providing care to several patients in the emergency department. Which patient is the priority when using the three-tiered triage system?

The following question(s) refer to the evolutionary tree in Figure 22.4, whose horizontal axis represents time (present time is on the far right) and whose vertical axis represents morphological change.