microevolution and speciation

Question 1

How is genetic variation stored in the gene pool?

Answer 1

A gene pool is made up of all the possible alleles in a population

Question 2

How do allele frequencies change in a population?

Answer 2

With evolution, allele frequency in a population changes overtime

Question 3

What are sources of variation within a population?

Answer 3

Sexual reproduction, mutations, gene flow

Question 4

Know how to calculate allele frequencies

Answer 4

of homozygous alleles times 2 + # of heterozygous individuals/ population # times 2

Question 5

Know the relationship between allele frequency and gene pool

Answer 5

The # of times an allele occurs in a gene pool compared to the total number of alleles

Question 6

Directional selection

Answer 6

favors phenotypes at one extreme (mean is shifted left or right)

Question 7

stabilizing selection

Answer 7

stabilizing selection: favors the intermediate phenotype (mean is in the middle)

Question 8

disruptive selection

Answer 8

disruptive selection: favors both extreme phenotypes, peak is at 2 areas

Question 9

What is microevolution?

Answer 9

Change in genes of evolution

Question 10

How can allele frequencies be used to determine if a population is undergoing microevolution?

Answer 10

Microevolution is change in genes of evolution, so changes in allele frequencies overtime shows changes for the gene of the alleles

Question 11

How can that data be used to determine if natural selection has occurred.

Answer 11

Data can show changes in frequency of traits, natural selection will favor a certain trait while genetic drift is by chance

Question 12

Describe mechanisms for evolution of populations other than natural selection?

Answer 12

genetic drift, bottleneck effect. founder effect, gene flow, sexual selection

Question 13

genetic drift

Answer 13

random changes in allele frequencies and affects small populations and causes loss of genetic diversity

Question 14

bottleneck

Answer 14

change In allele frequency following a dramatic reduction in the size of a population, reduces a SMALL population’s genetic variation by a lot

Question 15

founder effect

Answer 15

genetic drift that occurs after start of a new population, founding of a small population can lead to genetic drift, occurs when a few individuals start a new population

Question 16

gene flow

Answer 16

movement of genes (migration) which introduces new alleles into a population or alters allele frequencies

Question 17

sexual selection

Answer 17

when certain traits increase mating success

Question 18

Describe two ways populations can become small enough to experience genetic drift.

Answer 18

Bottleneck or founder effect

Question 19

What is speciation?

Answer 19

The rise of 2 or more populations from 1 existing species

Question 20

How does speciation occur?

Answer 20

Reproductive barriers must be present

Question 21

What types of isolation can result in speciation?

Answer 21

behavioral, geography, temporal, anatomical

Question 22

Behavioral isolation

Answer 22

Different behaviors for attracting mating can prevent interbreeding between 2 species.

Question 23

Geography

Answer 23

Species cannot reproduce if they cannot live in the same environments as another species

Question 24

temporal

Answer 24

If groups mate at different times, they are most likely not going to interbreed

Question 25

anatomical

Answer 25

- Reproduction requires the right kind of anatomy between species

Question 26

convergent

Answer 26

Convergent- when unrelated organisms evolve similar characteristics/looks due to similar environmental conditions, no common ancestor

Question 27

divergent

Answer 27

Divergent- when organisms, initally sharing a common ancestor, evolve into increasingly distinct species or populations due to different selective pressures or enviornmental conditions