Bio 123: PP4 Material

Question 1

Define microevolution

Answer 1

The change in allele frequencies in a population throughout time.

Question 2

Explain the Hardy-Weinberg Equilibrium Model

Answer 2

It is used as a baseline to compare an evolving population to one that remains constant without evolutionary forces acting upon it. There are positive controls and negative controls. There is a part missing, ask classmate for his notes that he wrote

Question 3

What are the four processes that drive populations out of genetic equilibrium?

Answer 3

1) Mutations
2) Genetic Drift
3) Gene Flow
4) Selection

Question 4

What are mutations?

Answer 4

Raw material for evolutionary change. They are changes in alleles. They also occur at relatively low rates and can appear more often due to exposure to hazardous material such at radioactive material.

Question 5

What are the conditions under the Hardy-Weinberg equilibrium?

Answer 5

Evolution is not occurring if:
1) No mutations occur
2) There is no genetic flow (meaning that the population is fully isolated)
3) The alleles present have no effect on the survival or reproduction ability of that population
4) Random mating (there is no active mate choice)

Question 6

What is the purpose of having a genetic equilibrium model (the Hardy-Weinberg Model)?

Answer 6

It serves to positively identify the mechanisms that drive changes in allele frequency.

Question 7

Polygenic

Answer 7

Multiple alleles that control a trait

Question 8

Incomplete Dominance

Answer 8

Bb

Question 9

Complete Dominance

Answer 9

ignore

Question 10

Deleterious mutation

Answer 10

Mutations that have a negative affect and decreases an organisms fitness.

Question 11

Lethal Mutations

Answer 11

Mutations that lead to the death of an organism. The organism is not even born.

Question 12

Neutral Mutations

Answer 12

Mutations that have 0 affect on an organisms fitness.

Question 13

Beneficial Mutations

Answer 13

Mutations that have a positive affect on an organisms fitness and is therefore favored by natural selection.

Question 14

Genetic Drift

Answer 14

In small populations, some alleles can randomly become fixed (one allele can be at 100% and the other ends up at 0%) which causes a loss of some alleles and an overall loss of genetic diversity.

It usually results in a decline of an organism fitness.

Question 15

What is Homozygous Dominant?

Answer 15

AA

Question 16

What is Heterozygous?

Answer 16

Bb

Question 17

Where do we typically see genetic drift occur and why?

Answer 17

In small populations because there is already a much smaller genetic diversity within small populations. It causes allele frequencies to change at random and leads to a loss of genetic variation within a population. It can also cause harmful alleles to become fixed in a population (due to increased inbreeding and mortality).

Question 18

Explain the Bottleneck Event

Answer 18

In a bottleneck event, some catastrophe (such as a natural disaster or a disease outbreak) occurs and the surviving population only has a fraction of the alleles that were present in the population before the catastrophe.

Question 19

Explain the Founder Effect

Answer 19

When a few individuals from a population start a new population with a different allele frequency than the original population.

Question 20

What is the Greater Prairie chicken example?

Answer 20

They only live in undisturbed grassland and because humans have turned grasslands into farming lands, the greater prairie chicken went from having a 5.2 alleles per locus to a 3.7 which reduced their survivorship to less than 50 percent.

Question 21

What are anthropologically caused events?

Answer 21

Events caused by the human race or through human action.

Question 22

Define habitat fragmentation

Answer 22

When parts of a habitat are destroyed, leaving behind smaller, unconnected areas.

Question 23

Define Migration

Answer 23

Movement of alleles between populations.

Question 24

Define Gene Flow

Answer 24

The transfer of alleles from the gene pool of one population to the gene pool of another population. It causes allele frequencies to shift.

Question 25

Explain what conservation applications are

Answer 25

Efforts that aim at increasing Gene flow within small populations, promoting genetic diversity across subpopulations such as the use of wildlife corridors.

Question 26

What were wildlife corridors?

Answer 26

Pieces of land/area that connects populations of the same species that are in different areas in order to promote them to reproduce and increase genetic diversity.

Question 27

Define Directional Selection

Answer 27

In directional selection, allele frequencies give rise to a range in variation in phenotype that tend to shift in 1 consistent direction. One extreme end of the trait is going to be favored. It can also lead to extreme behaviors such as extreme mating dances.

Question 28

What happens during Stabilizing Selection?

Answer 28

Neither extreme end is favored. Meaning that the intermediate forms of a trait in a population are favored.

Question 29

What is an example of Stabilizing Selection?

Answer 29

The Sociable Weaver. Cannot be too small or else they will not be selected by female to mate with and cannot be too big because then they will be slower is escaping predators such as snakes.

Question 30

What happens during Disruptive Selection?

Answer 30

Forms on both ends of the range of variation are favored and intermediate forms are selected against.

Question 31

What is any example of Disruptive Selection?

Answer 31

African Finch populations in Cameroon. Small and sharp beaks as well as thicker beaks are favored for depending on the type of food that is available for them.