Chapter 18 Quiz

. Observations of the biogeographic distributions of organisms provided both Darwin and Wallace with evidence for the occurrence of evolution. Which of the following was not part of the evidence used by Darwin to support his theory of descent with modification?

Organisms inhabiting similar climates are not necessarily related.

Physical barriers to dispersal often separate regions with very different groups of animals.

Animals from different habitats on the same continent are more closely related to each other than they are to animals from similar habitats on different continents.

Inhabitants of islands are clearly related to species on the nearest mainland, suggesting a continental origin followed by dispersal to the island.

Species distributions are closely aligned with the movement of continents.

. Wallace's line is a deep-water boundary that separates islands that differ greatly in their fauna, despite their close proximity and similar climate. Accordingly, these islands are assigned to two different biogeographic realms, each of which has a large number of species that are restricted to that location and found nowhere else in the world. These species are considered

ancestral.

indigenous.

native.

endemic.

cosmopolitan.

. Which of these is an example of an organism with a disjunct distribution?

Giant anteaters are found only within the Neotropical realm.

Pigeons, family Columbidae, are found worldwide.

Florida scrub jays are found only in a specific type of habitat in Florida.

European starlings are found in Europe and North America.

Homo floresiensis survived in an isolated population on the island of Flores for much longer than any other hominin (besides H. sapiens).

. If a population of kangaroos (known as a dominant mammal in Australia) was discovered living on island northwest of Wallace's line, which of these would be the most likely explanation?

The population was recently founded by kangaroos that dispersed there from Australia.

This population is a relict from the time when marsupial mammals had a worldwide distribution.

The population was isolated by a recent vicariant event.

Kangaroos are superior competitors to the mammals from the Oriental biogeographic realm.

Wallace's line is an inaccurate representation for the faunal break in this particular region.

. The two main hypotheses for a taxon's distribution are dispersal and vicariance. Which of the following would be the poorest source of data for testing these hypotheses?

Geological patterns, like mountain formation or continental drift

Paleontological data, including the presence or absence of fossils in a region

Phylogenetic data, in which geographic distributions are treated analogously to character states

"Unbalanced" biota—that is, an area lacks taxa it would be expected to have if it were joined to other areas

The current geographic distribution of the organism

. The Isthmus of Panama formed about 3 million years ago, isolating the Caribbean Sea from the Pacific Ocean. Which observation would provide evidence that sister species of angelfish found on either side are the result of a vicariance event cause by the formation of the landmass, rather than the dispersal of a founder population across the Isthmus?

The molecular clock dates the divergence time between the species to be 3 million years or greater.

The molecular clock dates the species' divergence time to be less than 3 million years.

The molecular clock shows that one species is much younger than the other.

A phylogeny shows that the Pacific angelfish are monophyletic and nested within the Caribbean angelfish clade.

The Caribbean angelfish have only a fraction of the parasites and diseases of the Pacific angelfish.

. You examine four forested Caribbean islands. Each has four species of Anolis lizard that use four ecological niches (for a total of 16 species). On each island, one species exclusively occupies either the ground, tree trucks, limbs and branches, or the smallest twigs and leaves. Phylogenetic analysis shows that the species on each island form their own monophyletic groups. Which is the best explanation for this pattern?

Four lizard species colonized each island, and they maintained the ecological niche that they had in their ancestral home.

The lizards diversified into four species on one island, then subsequently, some of those dispersed and diversified on the other islands.

Each island was founded by a colonizer, perhaps from a mainland, and divided up ecological niche space as they diversified into the four species present.

One lizard species evolved a broad fundamental niche on each island, then dispersed to the other islands, where they were restricted to narrowed realized niches.

All 16 species were historically present on all islands, but resource competition only allows four to survive on each island.

. The phylogeographic analysis in the figure shows that the grasshopper Chorthippus parallelus expanded its range through northern and central Europe from the Balkans after the last glacial period, but it could not cross mountain ranges in southern Europe. In contrast, a similar analysis found that hedgehogs colonized northern Europe from all three areas.

How might the pattern of mitochondrial DNA haplotypes across European hedgehog populations differ from grasshoppers?

Northern and central European populations would likely contain haplotypes from all three refugial regions.

Haplotypes would likely be different among all European populations.

Populations from northern and central Europe would be expected to have haplotypes similar to Balkan regions.

Populations from northern and central Europe would be expected to have haplotypes similar to Iberia and Italy.

Populations from all three refugial areas would be expected to be similar but different from northern and central Europe.

. Which observation does not provide evidence that modern humans dispersed from Africa to the rest of the world (according to the "out of Africa" theory)?

Fossils that represent modern humans' immediate ancestors are found only in Africa.

Human mitochondrial haplotype diversity is greatest in Africa and declines as distance from Africa increases.

Humans in specific regions have distinct adaptations to the environment in those regions.

Human populations in regions outside of Africa usually show evidence of descent from a relatively small group of founders.

All of the above provide evidence for the "out of Africa" theory.

. After the breakup of Gondwana, new species evolved in South America, Africa, and Australia. Which speciation model best fits this vicariance event?

Allopatric speciation

Sympatric speciation

Parapatric speciation

Peripatric speciation

Hybrid speciation

. Refer to the figure showing a phylogeny of the cypresses.

The phylogeny in the figure suggests that the distribution of cypress species is best explained as

vicariance only.

dispersal only.

a vicariant event, followed by several dispersal events to Africa.

dispersal to Africa, followed by several vicariance events.

cycles of dispersal, followed by vicariance, then dispersal again.

. You discover patterns of genetic divergence that are very similar among multiple unrelated species that share a region. This suggests that

the organisms have an ecological relationship and are tracking one another.

the organisms are probably more closely related to one another than was previously thought.

the species experienced a similar history of subdivision, owing to geological and climatic processes.

by random chance the organisms have colonized new areas following the same dispersal routes.

the genes of these organisms are under strong selection, and thus these species are not useful for biogeographic analysis.

. Many temperate plant taxa have not adapted to tropical environments, and many animal species shifted their ranges during the Pleistocene rather than adapting to climate change. These observations are consistent with

physiological tolerance.

phylogenetic niche conservatism.

community convergence.

local adaptation.

phylogenetic signal.

. Which statement offers the best explanation for why the only native land mammal to Hawaii is the Hawaiian hoary bat?

Because of phylogenetic niche conservatism, other mammals could not adapt to use any of the open niche space in Hawaii.

Most mammals were unable to successfully disperse long distances over oceans and colonize Hawaii.

Other mammals were competitively excluded by the birds and reptiles that are native to Hawaii.

Volcanic activity drove the other mammals to extinction on Hawaii.

Hawaii formed and was isolated before the evolution of mammals in the Mesozoic era.

. Different models for species accumulation have been proposed to account for the difference in species richness between tropical and temperate regions. Which model best describes the greater diversity of treefrogs (Hylidae) in the tropics compared to the temperate zone?

Diversification rate hypothesis

Ecological hypotheses based on carrying capacity

Replacement hypothesis

Time and area hypothesis

Vicariance hypothesis

Chapter 18 Quiz

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