Exam 21: Reconstructing and Using Phylogenies

Unrelated lineages of rodents that moved to islands have increased in size relative to close relatives that are on the mainland.This increase in size is an example of _______ which is a type of _______.

Whales and pigs diverged about 80 million years ago.Suppose a DNA sequence has had 48 changes between whales and pigs.The same DNA sequence has had 6 changes between two different species of whales.Assuming a molecular clock is operating, the whale species diverged _______ million years ago.

Refer to the table. The table shows the divergence times (time since last common ancestor) between different species of butterflies and the numbers of changes that have occurred at two different genes.If two species of these butterflies had 200 differences in the gene for alcohol dehydrogenase, approximately how long ago did they diverge from a common ancestor, assuming that they were evolving in accordance with the molecular clock?

Suppose researchers know that two species of fish began diverging from a common ancestor when they were separated by the formation of the Isthmus of Panama 6 million years ago.The genetic divergence between these two species at the hypothetical HYR gene is 3 percent.[Note: The species have a total of 12 million years of evolutionary divergence, 6 million in each lineage.] The rate of evolutionary change at this gene in these species is _______ percent per million years.

Refer to the figure showing a single viral plaque that was split every 400 generations and grown in the presence of a mutagen. How many generations of evolution have occurred between the A lineage and the E lineage? Remember that evolution is occurring in both lineages.

Why are frog calls generally more useful in phylogenetic analysis than bird songs?