Exam 1 cont.

Question 1

autopomorphy

Answer 1

singleton

Question 2

symplesiomorphy

Answer 2

conserved sites

Question 3

synapomorphy

Answer 3

parsimony informative site

Question 4

name the four types of evolutionary forces

Answer 4

gene flow: bee carrying pollen between flower populations, mutation: sickle cell anemia, genetic drift: a natural disaster kills off all of the individuals with one allele increasing the frequency of individuals with another allele, natural selection: bird beaks of finches adapting to their surroundings

Question 5

A virus is rampaging through the country affecting both high and low population densities. People in the high-density population contact more people. In which population density will high virulence be more favored? If low density communities still have people going out while sick, and the opposite is true of high-density communities, which population will favor higher virulence?

Answer 5

At first, virulence will be highest in the high population densities. In the second scenario, we would see the low population density favor higher virulence. Higher virulence is favored when there are more transmission events.

Question 6

What is the difference between convergent and parallel evolution?

Answer 6

Parallel evolution produces similar traits through independent, but the same pathways. Convergent = Bats vs Birds; Parallel = Different Crabs

Question 7

Name the three kinds of homoplasies

Answer 7

parallel, convergent, reversal

Question 8

How do you determine if a trait is ancestral or derived?

Answer 8

By the outgroup.

Question 9

Why do autapomorphies not help determine relatedness among taxa?

Answer 9

It only tells if a taxon is unique overall, not how similar they are to some versus other taxa.

Question 10

Why use a synapomorphy instead of a symplesiomorphy for tree building? Give two reasons

Answer 10

1. We use synapomorphies because they show us where the derived points, or transitions, have occurred. 2. Change is rarer than stasis.

Question 11

How do Maximum Parsimony differ from Maximum Likelihood?

Answer 11

MP attempts to determine the tree by using as few character state changes as possible while ML uses information about the probability of character state changes to determine the best tree.

Question 12

original: orthologs and paralogs

Answer 12

orthologs are X1, X2, X3, et cetera, paralogs: all Ys and Zs

Question 13

Select all that is true [about incomplete lineage]

Answer 13

Complete lineage sorting follows species divergences; incomplete lineage sorting can give accurate estimates

Question 14

[what is horizontal gene transfer defined by?]

Answer 14

Horizontal gene transfer is defined by the lack of sex

Question 15

Do introgressions give accurate, under, or overestimates of divergence times? Why?

Answer 15

Introgressions give underestimates of divergences because introgression occurs through interbreeding of two existing species

Question 16

Select all that apply: molecular clocks

Answer 16

Need to be calibrated by ancestors of similar taxa; rates differ by taxa life strategy (I.e., fast vs slow reproducing species)

Question 17

Select all that is true: phylogeography

Answer 17

Phylogeography takes into account continental histories; phylogeography uses taxa distributions and puts them geographic context; vicariance does not need to exactly match phylogeny of taxa to be congruent

Question 18

Give two fundamentally different fictional examples of dispersal

Answer 18

Range expansion and jump dispersal.

Question 19

Give a real or fictional example of coevolution and cospeciation

Answer 19

Coevolution= predator-prey interactions in toads; cospeciation = host-parasite Interactions in bird lice

Question 20

Select the true statements: [phylogenies]

Answer 20

Phylogenies between a host and its obligate parasites are often congruent; two phylogenies can be congruent in topology, but not in timing