Evolution and Population Genetics: Key Concepts and Simulations

What is the purpose of replacing the two beads after each draw in the simulation?

To ensure each individual has the same chance of contributing alleles to the next offspring, simulating random mating.

What causes the deviation from the original allele frequencies in the first generation?

Random chance (genetic drift) when drawing alleles, especially in a relatively small population.

How does increasing the number of individuals drawn per generation affect deviation from original frequencies?

The deviation would become smaller in a large population, as random sampling has less of an effect.

Which Hardy-Weinberg assumptions are met in this simulation?

Random mating, no mutation, no natural selection, no migration/gene flow.

Which Hardy-Weinberg assumption is not met in this simulation?

Large population size.

Why do zoologists encourage sharing threatened animals among different zoos?

It increases genetic diversity and gene flow, reducing the effects of genetic drift in smaller populations.

What can be inferred about human dispersal and evolution based on blood type frequencies?

Humans dispersed into different geographic regions, leading to different allele frequencies due to unique evolutionary histories.

Why do blood types vary between locations and cultures?

Due to different amounts of genetic drift, founder effects, migration/gene flow, and natural selection experienced by populations.

What is the probability of producing a homozygous recessive individual from generation 1?

0.0064 or 0.64%.

What is the probability of producing a homozygous recessive individual from generation 5?

0.1024 or 10.27%.

What will F(a) be after 10 generations?

Very close to 0.

What will F(a) be after 20 generations?

Even closer to 0.

How does the rate of change of F(A) compare to F(a) if A is a lethal allele?

F(A) would decrease faster than F(a) because a dominant lethal allele is expressed in both AA and Aa individuals.

How can lethal alleles persist in a large population for many generations?

A recessive lethal allele can hide in heterozygous carriers, allowing them to survive and reproduce without expressing the lethal phenotype.

What is the condition that causes severe liver disease in infancy in the Chicoutimi area of Quebec?

Tyrosinemia

What is the frequency of tyrosinemia in the Chicoutimi area?

1 in every 685 children

What is the value of q required to produce the proportion of afflicted newborns with tyrosinemia?

0.0382

What is the expected proportion of the population that would be heterozygous for tyrosinemia?

7.35%

What does it mean for an allele to become 'fixed' in a population?

It is the only allele left in the population.

What can happen to a fixed allele if natural selection favors it?

The population will thrive and grow.

What happens if natural selection does not favor a fixed allele?

The species may go extinct due to lack of variation.

Why did different classmates have different colors of surviving invertebrates in the crashing logs simulation?

The logs could only capture one organism at a time, allowing for color adjustments.

How does phenotype influence the survival and reproduction of invertebrates?

Phenotypes that blend into the environment have better survival rates.

What was the effect of a small population size on mussel color morph in simulations?

It quickly caused extinction compared to a larger, more stable population.

What conditions make it less likely for a color morph to randomly go extinct?

A larger population size increases allele frequency stability.

What is the predicted effect of oystercatchers developing a search image on invertebrate colors?

They will likely prey on the phenotype that has survived the longest.

Is evolution totally random, totally predictable, or somewhere in between?

Evolution is somewhere in between; some traits show predictable survival rates while randomness can affect allele frequencies.

What type of selection could occur for clams if larvae are carried to a beach with white sand?

Directional selection

How does the environment affect an organism's potential for fitness?

Fitness is dependent on the environment; traits successful in one environment may not thrive in another.