Exam 21: Reconstructing and Using Phylogenies

Suppose that mice and humans differ by 20 substitutions in their globin genes, and rats and mice differ by 5 substitutions.On the basis of other evidence, we know that the ancestor to humans and mice lived 80 million years ago.Assuming the molecular clock is operating, rats and mice split from each other _______ million years ago.

When constructing phylogenetic trees, biologists often rely on the principle of _______, which states that the preferred phylogeny is the one that requires the fewest homoplasies.

Binomial nomenclature means that species are referred to

Maximum likelihood methods are most likely to be an improvement over parsimony methods when

Which of the following cannot be a homologous trait?

Assume DNA from samples of a virus in 2018 diverged, on average, 9 percent from a virus found in a person from 1988.If the total amount of divergence among contemporary samples were 27 percent, then the virus most likely would have entered the human population in the year _______, assuming a molecular clock.

Biologists have described well over a million species of eukaryotes.Most species that have been described are known primarily by their

Some species of Drosophila have elaborate "picture wings," whereas most others do not.Which type of evidence would most likely suggest that the elaborate picture wings evolved via convergent evolution?

What would you find at the root of a phylogenetic tree?

A taxon of flies can be removed from a phylogenetic tree by a single cut.Thus, this taxon is

A skeptic argues that because phylogenetic methods can be flawed, the results from such methods are questionable.What result or analysis provides the best validation of the accuracy of the methods used to reconstruct phylogenetic relationships?

Gibbons are more distantly related to humans, chimpanzees, and gorillas than these three are related to one another.Thus, gibbons are considered to be a(n) _______ in relation to the other three.

Species A and B are sister species.Species C and D are also sister species.The lineage leading to species A and B diverged from the lineage leading to species C and D at node 1.Prior to node 1, the lineage leading to species E diverged from the lineage leading to species A, B, C, and D at node 2.Suppose a newly discovered species (species F) was determined to be the sister species of species E.Which would then be monophyletic groups?

Which sequence represents a correct size ranking of taxonomic categories, from smallest to largest?

Whales and pigs diverged about 80 million years ago.If a DNA sequence has had 24 changes between whales and pigs, the rate of change for this sequence would be _______ changes per million years.

The ancestral archosaur had an opsin that was shifted to _______, suggesting that the animal was most likely active _______.

Two clades of beetles split off from a node more recently than these clades diverged from other clades.Thus, these clades are _______ clades.

Which concept adds a dimension of time to a phylogenetic analysis?

Two species of damselflies that are not sister species independently evolve a new mating behavior.This pattern is an example of _______, which is a(n)______.

Refer to the figure. The figure shows the phylogeny of seven species of beetles (A through G).The figure also shows whether the beetles have (marked with check) or do not have (marked with an x) one of three stripes.It also states the color of the beetle (R for red and G for green). The loss of stripe 3 in species _______ is an example of a homoplasy.