Exam 20: Phylogeny

The next questions refer to Table 20.1, 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 (e.g., 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 the DNA of another member of species A. Table 20.1 -Based on the tabular data, and assuming that time advances vertically, which cladogram (a type of phylogenetic tree) is the most likely depiction of the evolutionary relationships among these five species?

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

When using a cladistic approach to systematics, which of the following is considered most important for classification?

When it acts upon a gene, which of the following processes consequently makes that gene an accurate molecular clock?

Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes up

Figure 20.4 Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about 18 million years ago. Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time. -Assuming chimps and gorillas are humans' closest relatives, removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes

There is some evidence that reptiles called cynodonts may have had whisker-like hairs around their mouths. If true, then what can be properly said of hair?

Linnaeus was a "fixist" who believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with

Cladograms (a type of phylogenetic tree) constructed from evidence from molecular systematics are based on similarities in

The following questions refer to the phylogenetic tree in Figure 20.3, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer. Figure 20.3 A possible phylogenetic tree for the three domains of life. -If the early history of life on Earth is accurately depicted by Figure 20.3, then which statement is least in agreement with the hypothesis proposed by this tree?

Which eukaryotic kingdom is polyphyletic, and therefore unacceptable, based on cladistics?

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of

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

The best classification system is that which most closely

If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be

If cetaceans are determined to have diverged from the lineage leading to the artiodactyls before the divergence of lineages leading to the modern artiodactyls (including hippos), then the cetaceans can be considered 1. a sister order to the order Artiodactyla. 2) an ingroup of the order Artiodactyla. 3) the common ancestor of the order Artiodactyla.

Which kingdom has been replaced with two domains?

Use Figure 20.1 to answer the following questions. Figure 20.1 -If Figure 20.1 is an accurate depiction of relatedness, then which of the following should be correct? 1. The entire tree is based on maximum parsimony. 2) If all species depicted here make up a taxon, this taxon is monophyletic. 3) The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E. 4) Species A is the direct ancestor of both species B and species C. 5) The species present at position 3 is ancestral to C, D, and E.

If it turns out that the whale lineage diverged from the lineage leading to hippos after the divergence of the lineage leading to the pigs and other artiodactyls, and if the whales continue to be classified in the order Cetacea, then what becomes true of the order Artiodactyla?

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?