Exam 25: Phylogenies and the History of Life

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?

Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran fauna?

Whatever its ultimate cause(s), the Cambrian explosion is a prime example of ________.

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves ________.

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia?

Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator-prey relationships? The fossil record reveals an increased incidence of ________.

The common ancestors of birds and mammals were very early (stem) amniotes, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as ________.

Which of the following showed their greatest diversity during the Mesozoic era but were a small, less diverse group during the Paleozoic era?

Which of the following statements best describes the rationale for applying the principle of parsimony in constructing phylogenetic trees?

Refer to the following information to answer the question below. -Which of the following statements is correct?

The question(s) below refer to the following table, which compares the % sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (for example, Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A. -Based on the tabular data, and assuming that time advances vertically, which phylogenetic tree is the most likely depiction of the evolutionary relationships among these five species?

Ichthyosaurs, now extinct, were aquatic reptiles with dorsal fins and tails, similar to those of fish. Their most recent ancestors were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are ________.

In the accompanying phylogenetic trees, numbers represent species and the same species are shown in both trees. Which two species are represented as sister species in Tree 2 but are not shown as sister species in Tree 1?

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). If the molecular data best reflect the evolutionary history of these two groups, then the morphological similarities of these two species is most likely due to ________.

Which of the following organisms would be most likely to fossilize?

To apply parsimony to constructing a phylogenetic tree, ________.

On the basis of their morphologies, how might Linnaeus have classified the Hawaiian silverswords? Linnaeus would have ________.

Given that phylogenies are based on shared derived characteristics, which of the following traits is useful in generating a phylogeny of species W, X, Y, and Z?

-According to the theory of sea-floor spreading, oceanic islands, such as the Hawaiian Islands depicted in the accompanying figure, form as oceanic crustal plates move over a stationary "hot spot" in the mantle. Currently, the big island of Hawaii is thought to be over a hot spot, which is why it is the only one of the seven large islands that has active volcanoes. What should be TRUE of the island of Hawaii? 1) Scientists in search of ongoing speciation events are more likely to find them here than on the other six large islands. 2) Its species should be more closely related to those of nearer islands than to those of farther islands. 3) It should have a rich fossil record of terrestrial organisms. 4) It should have species that are not found anywhere else on Earth. 5) On average, it should have fewer species per unit surface area than the other six islands.

The best classification system is that which most closely ________.