Exam 26: Phylogeny and the Tree of Life

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 would, if it had acted upon a gene, prevent this gene from acting as a reliable molecular clock?

Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium?

The best classification system is that which most closely ________.

If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?

In a comparison of birds and mammals, having four limbs is ________.

To apply the principle of maximum parsimony to construction of a phylogenetic tree, ________.

The question refers to the following table, which compares the percent 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. % Sequence Homology Species Intron I Exon I Intron VI Exon V A 100\% 100\% 100\% 100\% B 98\% 99\% 82\% 96\% 98\% 99\% 89\% 96\% 99\% 99\% 92\% 97\% 98\% 99\% 80\% 94\% Which of these four gene parts should allow the construction of the most accurate phylogenetic tree, assuming that this is the only part of the gene that has acted as a reliable molecular clock?

A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?

If organisms A, B, and C belong to the same class but to different orders and if organisms C, D, and E belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

The kingdom Monera was dismantled because of which of the following reasons?

In the 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?

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that ________.

- If the figure above is an accurate depiction of relatedness, then which of the following should be an accurate statement?

The various taxonomic levels (for example, phyla, genera, classes) of the hierarchical classification system differ from each other on the basis of ________.

In the above figure, which similarly inclusive taxon is represented as descending from the same common ancestor as Canidae?

Some beetles and flies have antler-like structures on their heads, much like male deer. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of ________.

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

Which of the following pairs are the best examples of homologous structures?

To apply parsimony to constructing a phylogenetic tree,