Exam 1 Flashcards
The same phylogenetic pattern will occur in multiple lineages when
vicariance accounts for the pattern
Which of the following often results in polytomies?
Rapid radiation of lineages.
When trying to resolve the phylogenetic relationships among groups that diverged very recently (for example, divergence of closely related species):
None of the following is true: homologies may have resulted in saturation of some molecules; rapidly evolving molecules are likely to have reached saturation; slowly evolving molecules are likely to be most useful
A molecular clock:
Usually uses a dated fossil to calibrate the rate of molecular change; is based on the idea that some molecules evolve at a fairly constant rate; can be used to estimate divergence times between taxa that do not have good fossil records; all of the above
Incomplete lineage sorting often leads to
over-estimates of divergence times; incorrect conclusions about taxonomic relationships
Coding regions of DNA tend to accumulate mutations more slowly than non-coding regions because:
In coding regions, nonsynonymous mutations are usually selected against, resulting in their elimination
Saturation of the molecular signal occurs because:
Even though molecules continue to accumulate more mutations over time, this does not result in increasing numbers of molecular differences in the different lineages (taxa)
When trying to determine if a taxonomic group is monophyletic, polyphyletic or paraphyletic it is necessary to consider
If a CA and all descendant taxa are included; if the taxa are joined based on ancestral vs derived traits
Assuming that the parasitoid lifestyle is ancestral in the Aculeate hymenoptera, the group containing all tiphioid-pompiloid wasps is (Johnson et al)
paraphyletic
Assuming that being eusocial is a derived trait, if all the eusocial taxa are grouped based on social structure, this grouping is (Johnson et al)
polyphyletic
Some wasps (Vespidae) and all ants (Formicidae) are eusocial. When considering the eusocial wasps and the ants, eusociality is a (Johnson et al)
synapomorphy; homoplasy
When doing a phylogenetic analysis of the Aculeate hymenoptera, which of the following is likely to be the most suitable outgroup (Johnson et al)
butterflies
original: two end taxa are more closely related relative to
the distance of the CA to the end taxa
original: a tree with changes is parsimonious
if it displays the least amount of change
original: do nested phylogenies suggest HIV infection?
yes
