Exam 22: The Origin of Species

If you build a canal linking a predator-rich pond to a predator-poor pond,then what type of selection should subsequently be most expected among the mosquitofish in the original predator-rich pond,and what type should be most expected among the mosquitofish in the formerly predator-poor pond?

Using only the information provided in the paragraph,which of the following is the best initial hypothesis for how D.santomea descended from D.yakuba?

Which of these phrases describes a stable hybrid zone?

In a hypothetical situation,the National Park Service,which administers Grand Canyon National Park in Arizona,builds a footbridge over the Colorado River at the bottom of the canyon.The footbridge permits migration to occur between populations of two closely related antelope squirrels.Previously,one type of squirrel had been restricted to the terrain south of the river,and the other type had been restricted to terrain on the north side of the river.Immediately before and 10 years after the bridge's completion,researchers collected 10 antelope squirrels from both sides of the river,took blood samples,and collected frequencies of alleles unique to the two types of antelope squirrels (see the graphs in Figures 22.2 and 22.3). Figure 22.2 Figure 22.3 The data in these graphs indicate that

Dogs (Canis lupus familiaris)and gray wolves (Canis lupus)can interbreed to produce viable,fertile offspring.These species shared a common ancestor recently (in geologic time)and have a high degree of genetic similarity,although their anatomies vary widely.Judging from this evidence,which two species concepts are most likely to place dogs and wolves together into a single species?

The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is

Macroevolution occurs

Which of the following statements about speciation is correct?

There are currently two large,permanent bridges that span the Panama Canal.The bridges are about 8 miles apart.If snapping shrimp avoid swimming at night and avoid swimming under shadows,then what do these bridges represent for the snapping shrimp?

The largest unit within which gene flow can readily occur is a

A hybrid zone is properly defined as

Imagine a very large volcanic eruption occurs,and a 20 km-wide lava flow moves into a valley and separates it into two halves.How might this affect resident species with regard to allopatric speciation?

Figure 22.5 Which of the following is evidence for allopatric speciation by the formation of the Isthmus of Panama?

If the low number of hybrid flies in the hybrid zone,relative to the number of D.santomea flies there,is due to the fact that hybrids are poorly adapted to conditions in the hybrid zone,and if fewer hybrid flies are produced with the passage of time,these conditions will most likely lead to

Imagine two species of snakes that live in a tropical rain forest of Malaysia do not typically interbreed.In nature,one species is ground-dwelling and feeds mainly on insects and small amphibians near water,whereas the other snake feeds in the lower to mid-canopy of trees and vines rising from the forest floor.However,at a zoo in Singapore where they were kept in the same gallery exhibit,the two species were observed interbreeding and produced viable offspring.Which of the following reproductive barriers is most likely preventing these species from interbreeding in the forest?

Which of these evolutionary trees represents the situation described in the paragraph? (Note: D.yakuba (I)represents the island population,and D.yakuba (M)represents the mainland population. )

The following questions 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. Figure 22.4 -Which species is most closely related to species W?

Which of the following factors would not contribute to allopatric speciation?

You are an undergraduate student working with a graduate student in an entomology lab,and she presents you with a box of preserved grasshoppers of various species that are new to science and have not been described.Your assignment is to help her separate them into species.There is no accompanying information as to where or when they were collected.Which species concept will you have to use?

Evolution of a new species can occur