Combining macro and micro evolution

Question 1

What is microevolution?

Answer 1

The change in allele frequencies that occurs over time within a population. It is due to 5 different processes: mutation, selection, gene flow, gene migration and genetic drift.

Question 2

What is the idea of the Hardy-Weinberg equilibrium?

Answer 2

That if no evolution is occuring, genotypic frequencies will remain constant.

Question 3

What is macroevolution?

Answer 3

Major evolutionary change, especially with regard to the evolution of whole taxonomic groups over long periods of time.

Question 4

How the diversity seen in nature be explained?

Answer 4

By looking and microevolution and macroevolution and combining the effects together.

Question 5

How can microevolution explain macroevolution?

Answer 5

Speciation may only involve a small number of genetic changes, speciation and diversification can occur very rapidly, the Earth is old and there has been enoigh time to accumulate the number of species today and small genetic changes can have large effects on phenotype.

Question 6

Define mutation.

Answer 6

The introduction of alleles via changes in the nucleotide sequence of DNA.

Question 7

Define migration.

Answer 7

The movement of alleles or genotypes in and out of a population.

Question 8

Define genetic drift.

Answer 8

Changes in allele frequencies due to random sampling effects between generations.

Question 9

Which factor drives speciation and which factor opposes speciation: Drift or migration?

Answer 9

Drift drives speciation and migration opposes speciation.

Question 10

What is the idea of bean bag genetics?

Answer 10

That a high sampling error occurs with small samples.

Question 11

What is the Founder effect?

Answer 11

The idea that in small populations there is an increased chance of rare alleles due to inbreeding.

Question 12

What is the strength of genetic drift in terms of N?

Answer 12

1/2N, the inverse of the 2N numbers of breeding adults in a population.

Question 13

How does average genetic variance among populations change with random genetic drift?

Answer 13

Variance increases - contributes to speciation.

Question 14

How does average genetic variance within populations change with random genetic drift?

Answer 14

Variance decreases - this limits Natural Selection.

Question 15

What is intermittent drift?

Answer 15

Large fluctuations in population size from one generation to the next.

Question 16

What are bottleneck effects?

Answer 16

When populations are reduced to near extinction but then expand to large numbers.

Question 17

What is an example of a population bottleneck?

Answer 17

The Florida Panther.

Question 18

What are some of the reproductive problems of inbreeding in the Florida Panther?

Answer 18

80% of males have low sperm counts, 93% have abnormal sperm, there is a high frequency of kinked tail and there is a congenital heart defect - hole in the heart.

Question 19

How can you counteract random genetic drift?

Answer 19

Artificial migration or gene flow. You can bring in genetically different panthers from a Texas subspecies and outbreed. This means the hybrid individuals will be heterozygous and the reproductive problems will be absent.

Question 20

What is the problem with the mating system in the Northern Elephant Seal?

Answer 20

It is a harem polygynous mating mating system - males compete for the females by fighting to impress them. This results in there being a lot more females present in the population.

Question 21

What is the consequence of the mating system in the seals?

Answer 21

There is extreme variation in male reproductive fitness which results in very high levels of random genetic drift. The females are all breeding but only a few males can breed, so genetic drift increases.

Question 22

How can you calculate the strength of random genetic drift?

Answer 22

Using the harmonic mean.

Question 23

What dictates the strength of random genetic drift?

Answer 23

The type of mating system.

Question 24

What is an example of a population that has experienced the founder effect?

Answer 24

Amish - religious isolate population.

Question 25

What is inbreeding?

Answer 25

Matings between gentically related individuals. It increases homozygosity and leads to a high incidence of recessive, genetic diseases.

Question 26

What are some of the recessive genetic diseases seen in the amish population?

Answer 26

Ellis-van Creveld syndrome (dwarfism, heart problems), Pyruvate kinase deficiency (blood disorder) and hemophilia (sex-linked bleeding disorder).