Exam 21: Reconstructing and Using Phylogenies

Refer to the figure showing a phylogenetic tree. Should the common ancestor of lizard and salamander be considered an amniote? Explain.

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.Graph the relationship between the divergence time and the number of changes in the gene for alcohol dehydrogenase.Explain why we can say that the gene is evolving as expected under the principle of the molecular clock?

Genes that code for enzymes used in central metabolism generally evolve very slowly.Thus, these genes would most likely be used to study

Species A and B have long wings, whereas species C has short wings.Which piece of evidence would best support the hypothesis that long wings are a synapomorphy?

Not counting the root, how many nodes are in a phylogenetic tree with five species?

Which taxonomic category is next smallest than a phylum?

The mitochondrial genes in plants evolve more slowly than the mitochondrial genes in animals.Thus, phylogenetic analyses using mtDNA

From a survey of Martian life, three hypothetical species have been found and nicknamed krons, furs, and pars.If krons and furs are sister species, the resulting phylogenetic tree will have 28 homoplasies.If krons and pars are sister species, the tree will have 22 homoplasies.Krons and pars have red body patches, whereas krons and furs have striped bodies.Based on the principles of parsimony, krons and _______ are sister species, _______ a synapomorphy.

Support for use of the sensory exploitation hypothesis to explain the evolution of female swordtails' preference for swords comes from phylogenetic analysis showing that the swords _______ the female preference evolved.

In a phylogenetic reconstruction experiment by Hillis et al., researchers used a viral culture, adding mutagens over the course of the experiment.This method _______ the accuracy of the reconstruction, because the mutagen _______ the amount of change and the degree of homoplasy that is typical of organisms measured in average phylogenetic analyses.

Refer to the figure showing a single viral plaque that was split every 400 generations and grown in the presence of a mutagen. Based on this tree, which lineage should share the most synapomorphies with the H lineage?

Which statement about HIV is true?

The trait that would be least useful in a phylogenetic analysis would be one that

Sciurus is the type genus of the squirrel family, which has the scientific name

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.The ZTG1 gene evolves twice as fast as the HYR gene.Assuming a molecular clock, you would expect a _______ percent genetic divergence at ZTG1 between two species of fish that diverged a million years ago.

Epigenetic changes (such as changes in methylation state) be useful in phylogenetic analyses if they

According to the evidence, the common ancestor of humans and chimpanzees lived about 6 million years ago.Based on a molecular clock, if a rapidly evolving gene shows 10 percent divergence between humans and chimpanzees and 0.6 percent divergence between humans and Neanderthals, then humans and Neanderthals diverged from each other _______ years ago.

Which kind of data would likely be the most useful for distinguishing ancestral traits from derived ones?

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 of a phylogenetic tree.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.Which grouping is not monophyletic?

Refer to the figure showing a phylogenetic tree. Should the common ancestor of crocodiles and pigeons be considered an amniote? Explain.