Simbio: Finches and evolution

Why are the birds discussed in this lab called Darwin’s finches?

a. Charles Darwin named the Geospiza Leodarwini, in honor of his son Leonard

b. They come from the Darwin Archipelago off the coast of Ecuador

c. Charles Darwin collected the first scientific specimen

d. John Gould placed them in the genus Darwinospiza

c

A medium ground finches ability to survive often depends on its beak size primarily because:

a. Birds with bigger beaks are socially dominant, and therefore get the best nest sites

b. Big size determines which seeds a finch can eat and how efficiently it can eat them

c. longer beaks make better weapons, which the birds used to defend themselves against predators

d. Larger beaked finches experience higher mating success

b

Which statement best describes the pattern of natural selection on beak size?

a. deep beaks are favored and dry years, while shallow beaks are favored in wet years

b. selection favors birds with bigger beaks

c. selection favors birds with smaller beaks

d. shallow beaks our favorite in large populations, while deep beaks are favored in small populations.

a

What can happen to a virtual finch population if the environment changes from what conditions to dry conditions (or vice versa) two rapidly?

a. The mutation rate may fall to zero

b. The distribution of beak sizes may cease to be bimodal

c. The finch population may go extinct

d. Beak size may cease to affect survival

c

The correlated traits exercise showed that:

a. When two characters are correlated, selection always favors larger values for both or smaller values for both

b. when two characters are correlated, one of them can evolve towards higher values, even if smaller values are better for survival

c. when two characters are correlated, selection is always strong on both or weak on both

d. When two characters are correlated, the optimal values and selection strengths rise and fall together

b

What happened to beak depths in the virtual finch population when selection on beak depth was eliminated (selection strength = 0) and mutation rate for alleles determining beak depth was greater than zero?

a. Average beak depth consistently increased

b. Average beak depth consistently decreased

c. The range in beak depths became larger

d. The range in beak depths became smaller

c

In the mountains and valleys excessive, which on the following parameters had the largest influence on whether the finch population evolved a bimodal distribution?

a. The speed at which the model ran

b. The difference in carrying capacity between the wet versus dry side

c. The number of chicks each pair of parents produced each year

d. How far the birds flew when looking for a mate

d

The final exercise, large and small seeds, showed that:

a. In the absence of geographical barriers, a population cannot evolve distinctive subpopulations

b. Bimetal distributions are likely to evolve when geographic barriers are absent

c. Mortal distributions only evolve when the populations food supply is divided into two types

d. Bio distributions can evolve when geographic barriers are absent

d

Under which of the following conditions is a population most likely to evolve a bimodal distribution?

a. Selection favors multiple distinct trait values, and similar individuals tend to mate with each other

b. Traits are strongly correlated, and a low carrying capacity keeps the population size small

c. Environmental conditions change rapidly, and a low mutation rate limits the establishment of new variance

d. Selection is weak, and individuals produce large numbers of offspring each generation

a

In the lab, which of the following factors made it more likely that similar individuals would mate with each other? (Check all that apply)

a. Selectivity in choosing mates

b. Availability of smaller seeds

c. Geographic barriers separating subpopulations

d. Longterm weather patterns

a, c