Exam 19: Population Genetics and Human Evolution

Genetic drift is a random process that can change the genetic structure of a population.

Comparative genome studies show that humans and chimpanzees shared a common ancestor approximately ____________ million years ago.

The measure of differential survival and reproductive success is termed ____________________.

To be effective as a force changing genetic diversity, drift requires

How can genetics be used as a tool to reconstruct the history of the human species?

The ultimate source of new alleles and genetic variability is ____________________.

Random mating is more effective in changing allele frequencies of a population than is mutation.

Mutation as a force in genetic diversity serves to

In a large population on a Pacific island, a few individuals had a mutation that caused them to have different colored eyes. After a hurricane, the population was reduced to only a few individuals, but some of those individuals had the rare eye color mutation. Now, after many generations, almost half of the population on this island has different colored eyes. This is an example of _____________.

Heterozygotes for the Tay-Sachs disease allele appear to have greater than normal resistance to ____________________.

The sickle cell allele is spread through the population in West Africa and maintained at a high frequency due to ____________________ advantage.

Genetically, humans and chimpanzees are _________ percent the same.

For codominant alleles, the frequency of the different phenotypes cannot be used to determine the allele frequencies.

To measure gene flow between populations, one must use genes for which the populations' frequencies are significantly different.

If a population is in genetic equilibrium, it is in equilibrium for alleles of all genes.

One would think that deleterious genes would be eliminated by natural selection, yet we have two human genetic disorders with a high carrier frequency, sickle-cell anemia and cystic fibrosis. Why has this high frequency for these conditions remained in the population?

Why is it that mutation, acting alone, has little effect on evolution? What other factors will magnify the effect?

A predictable effect of genetic drift in a small population is an increase in

Why is it easy to measure allele frequencies in a codominant allele system?

In a hypothetical population of 1,000 people, there is a hypothetical trait called pink toe. People who are homozygous dominant have red toes; those who are homozygous recessive have white toes; those who are heterozygous have pink toes. If 400 people have red toes, the number of people with pink toes is ______________.