Exam 1 cont. 2

Question 1

What is biological evolution?

Answer 1

A change in allele frequencies in a population not due to natural selection, but chance; a change in phenotypically heritable traits of a population over time

Question 2

List the four forces of evolution and give examples of each

Answer 2

Answer: Mutation: A new allele arises in a population, Gene flow: one population of caribou migrates and interbreeds with another herd, Genetic Drift: A allele type in a population dies out due to chance, and Natural Selection: One allele is favored in a population over another

Question 3

When comparing distantly related taxonomic groups versus closely related taxonomic groups we expect?

Answer 3

Closely related groups have more synapomorphies than distantly related groups

Question 4

Select all the true statements about homoplasy

Answer 4

Convergent evolution is when a pair of groups share a derived trait not due to a common ancestry; homoplasy reversals indicate a reversion back to the ancestral state

Question 5

Homoplasy is indicative of what type of taxonomic groups?

Answer 5

Polyphyletic grouping

Question 6

What are the advantages of molecular data to morphological data?

Answer 6

Molecular data has more characters; molecular data has many characters not under selection

Question 7

What is the difference between maximum likelihood and maximum parsimony?

Answer 7

Maximum parsimony chooses the best model as the one with the fewest character state changes; maximum likelihood chooses the best model through probability

Question 8

When we analyze genetic data to infer phylogenetic relationships, what is true?

Answer 8

We get a gene tree; we can get overestimates of the true divergence times; we can get underestimates of the true divergence times

Question 9

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

Answer 9

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