Exam 26: Phylogeny and the Tree of Life

To apply parsimony to constructing a phylogenetic tree,

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, the condition of having four limbs is

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 ________.

The following question refers to this phylogenetic tree, depicting the origins of life and the three domains. Horizontal lines indicate instances of gene or genome transfer. A possible phylogenetic tree for the three domains of life. If the early history of life on Earth is accurately depicted by the figure, then which statement is most in agreement with the hypothesis proposed by this tree?

Which of the following would be most useful in creating a phylogenetic tree of a taxon?

Use the following information to answer the question. Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis)that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics. In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species. (T. Monis, et al. 1999. Molecular systematics of the parasitic protozoan Giardia intestinalis. Mol. Biol. Evol. 16[9]:1135-44.) According to the phylogenetic tree in the figure above, G. intestinalis constitutes a ________ group.

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 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?

Carolus Linnaeus believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with ________.

Use the figure to answer the following question. The phylogenetic tree shown ________.

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

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

Imagine that you discovered the following information: Feature Bacteria Archaea Eukaryotes RNA polymerase small, simple complex complex Introns absent present present Antibiotic sensitivity sensitive insensitive insensitive Membrane Lipids C chains unbranched C chains branched C chains branched These data would support which of the following conclusions?

Molecular clocks are more reliable when ________.

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

The legless condition that is observed in several groups of extant reptiles is the result of ________.

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\% C 98\% 99\% 89\% 96\% D 99\% 99\% 92\% 97\% E 98\% 99\% 80\% 94\% 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?

Use the following information to answer the question. Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis)that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics. In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species. (T. Monis, et al. 1999. Molecular systematics of the parasitic protozoan Giardia intestinalis. Mol. Biol. Evol. 16[9]:1135-44.) By examining the phylogenetic tree diagrammed in the figure above, what conclusion can you draw about the species G. microti?

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