Evolution

Question 1

What factors alter hardy Weinberg equilibrium

Answer 1

natural selection (principal force), mutation, migration, non random mating

anything that changes allele frequency in gene pool

Question 2

What are the types of selection

Answer 2

Directional selection - conferring one phenotypic extreme is selected stabilizing selection - intermediate types are favored, disruptive selection - both extremes selected for

Question 3

What is fitness

Answer 3

An individual’s genetic contribution to future generations

relates to whether or not offspring is produced. If an individual dies before producing offspring, w=0. High selection against a phenotype will decrease the fitness of that phenotype.

Question 4

How does speciation happen

Answer 4

occurs when a gene pool divides into two or more separate pools

Question 5

what is genetic drift -

Answer 5

it is when the number of reproducing individuals in a population is too small to ensure all alleles in gene pool will be passed on to the next generation. One allele can disappear and one can be fixed

Question 6

How does inbreeding affect the population

Answer 6

increases homozygotes in population and decreases fitness (inbreeding depression) since a harmful homozygous allele can be spread

Question 7

How is a species defined

Answer 7

a group of interbreeding or potentially interbreeding populations that is reproductively isolated in nature from all other such groups

Question 8

How do species become reproductively isolated

Answer 8

pre zygotic and post zygotic mechanisms

Question 9

What is microevolution vs macroevolution

Answer 9

Microevolution - evolutionary change within population

macroevolution - evolutionary change leading to emergence of new species of other taxonomic groups

Question 10

What is true about a population

Answer 10

They live in the same geographic area

Question 11

What is true about the gene pool of populations

Answer 11

Most populations contain a high degree of heterozygosity

Question 12

What is true about natural selection

Answer 12

It is the principal force that shifts allele frequencies within large populations

Question 13

What is true about nonlethal recessive allelee

Answer 13

They have different degrees of selection based on intensity against the recessive allele

Question 14

What are additional consequences of the hardy Weinberg law

Answer 14

dominant traits don’t necessarily increase from one generation to the next, genetic variability can be maintained

Question 15

What does the hardy Weinberg model assume

Answer 15

Equal rate of survival and reproduction

No new alleles arise or created by mutation

No migration into or out of population

Infinitely large population

Random Mating

Question 16

How are frequencies for multiple alleles calculated

Answer 16

p + q+ r = 1

(p+q+r)^2 = p^2 +q^2 +r^2 +2pq +2pr +2qr = 1

Question 17

What is true about frequency of x linked traits

Answer 17

frequency of x linked allele in gene pool equals frequency of males expressing x linked trait

Question 18

What do mutations do

Answer 18

They create new alleles in the gene pool

Question 19

What are the forms of nonrandom mating

Answer 19

Positive assortive mating-similar genotypes are more likely to mate than dissimilar ones

Negative assortive mating - dissimilar genotypes are more likely to mate than similar ones

Inbreeding - mating individuals are related

Question 20

What are species and speciation

Answer 20

Species are a group of actually or potentially interbreeding organisms that is reproductively isolated in nature

Speciation is associated with changes in genetic structure of populations

Question 21

What does macroevolution lead to

Answer 21

Reproductive isolation between or among population

Question 22

What are monophyletic groups

Answer 22

Consist of an ancestral species and all its descendants

Question 23

How are molecular clocks measured

Answer 23

in terms of amino acid or nucleotide sequences