Exam #2

Question 1

proposed the Law of Succession: evolution explains the similarity between fossils of a location
-“on the law which has regulated the introduction of new species”

Answer 1

Alfred Russell Wallace

Question 2

continental drift: noticed geological features on separated continents match when continents imagined together
-faced great opposition: could not explain how the continents moved apart

Answer 2

Alfred Wegener’s

Question 3

plate tectonics, 1930s

Answer 3

Arthur Holmes

Question 4

process by which the geographical range of a taxon is split into discontinuous parts by the formation of a physical barrier to gene flow

Answer 4

vicariance

Question 5

“Population genetics is the most important, most fundamental body of theory in evolutionary biology”

Answer 5

Mark Ridley

Question 6

genetic variation is the foundation of evolutionary change if it follows:

Answer 6

1. mutations
2. recombinant sex and horizontal gene transfer
3. gene flow

Question 7

example is spiral direction

Answer 7

discrete trait

Question 8

example is skin color

Answer 8

continuous trait

Question 9

variation comes in many forms:

Answer 9

1. morphological
2. cellular
3. biochemical
4. molecular

Question 10

genetic effects
-inheritance, mutations

Answer 10

heritable

Question 11

material effects
-composition of yolk, alcohol consumption

Answer 11

non heritable

Question 12

changes that occur in individuals as a result of the environmental

Answer 12

environmental effects

Question 13

not forward looking

Answer 13

not progressive

Question 14

acts on existing traits
-occurs when there is a change in allele frequencies through time

Answer 14

nonrandom

Question 15

assumptions underlying Hardy Weinberg equilibrium:

Answer 15

1. organisms are diploid
2. only sexual reproduction occurs
3. generation are overlapping
4. allele frequencies are equal in the sexes

Question 16

-causes allele frequencies to change, often rapidly
-can lead to the loss of alleles except favored one

Answer 16

selection

Question 17

-introduces new alleles into a population
-recurrent maintains alleles in the population, even if they are deleterious

Answer 17

mutation

Question 18

-introduces new alleles into a population
-allele frequencies will become more homogeneous in the populations

Answer 18

migration

Question 19

leads to random change in allele frequencies=genetic drift

Answer 19

small population size

Question 20

-inbreeding increases homozygosity for all genes
-mate selection and directional selection can lead to the loss of alleles except favored one

Answer 20

non random mating

Question 21

hardy weinberg equilibrium tells us what would happen without assortative mating, natural selection, migration, and mutation

Answer 21

null hypothesis

Question 22

hardy weinberg equilibrium gives a mathematical demonstration that Medelian genetics preserves genetic variation

Answer 22

historical and conceptual importance

Question 23

hardy weinberg equilibrium greatly simplifies our previously complex model for population genetics

Answer 23

theoretical importance

Question 24

determines if the difference between the observed results and the excepted results in due to random chance alone
-does not prove/disprove if random chance is the only cause observed differences

Answer 24

chi squared test

Question 25

assumptions of Hardy Weinberg equilibrium:

Answer 25

1. no selection 2. no mutation 3. no migration 4. large populations 5. random mating

Question 26

most important variable in the theory of evolution and it can be measured relative to selection -it determines which genotype we can expect to see in the world today

Answer 26

fitness of genotypes

Question 27

differential survival and reproduction of particular heritable genotypes over other -can produce change rapidly in time even if it is a weak force

Answer 27

natural selection

Question 28

chance of survival of a genotype

Answer 28

fitness (W)

Question 29

measure of the relative fitness of a phenotype

Answer 29

selection coefficient (s)

Question 30

selectively neutral compared to the dominant phenotype

Answer 30

s=0

Question 31

complete lethality compared to the dominant phenotype

Answer 31

s=1

Question 32

the fitness of a genotype increases as the genotype frequency in the population increases -purifying selection -gives an advantage to common alleles --example: wing color in Heliconius butterflies

Answer 32

positive frequency dependent selection

Question 33

the fitness of a genotype decreases as the genotype frequency in the population increases -diversifying selection -gives an advantage to rare alleles --example: human influenza virus and plant self incompatibility alleles

Answer 33

negative frequency dependent selection

Question 34

measure of genetic diversity -high: increased diversity -low: decreased diversity --small populations are at a greater risk for this loss

Answer 34

heterozygosity

Question 35

some evolutionary changes are predictable constancy from generation to generation -example is natural selection

Answer 35

non random process

Question 36

some evolutionary changes are not predictable constancy from generation to generation -example if drift

Answer 36

random process

Question 37

-fluctuations in the frequencies of alleles due to random chance alone -most important in small populations

Answer 37

genetic drift

Question 38

governed by or involving equal chances for each of the actual or hypothetical members of a population

Answer 38

random

Question 39

not capable of being foretold; unknown in advance; irregular, not occurring at expected times

Answer 39

unpredictable

Question 40

all the gene copies in the population can be traced back to a single ancestor

Answer 40

coalescence theory

Question 41

merge or unite things; to merge or cause things to merge into a single body or group

Answer 41

coalesce

Question 42

population undergoes a drastic reduction in size as a result of chance events -lead to founder populations; have an affect on heterozygosity

Answer 42

bottleneck effect

Question 43

small group of individuals (with a reduced genetic identity) creates a new generation

Answer 43

founder effect

Question 44

true count

Answer 44

census

Question 45

successful count

Answer 45

effective

Question 46

effective size may be smaller than census size for many reasons:

Answer 46

1. variations in population size (population bottleneck) 2. variance in reproductive success (not all members are successfully mating) 3. dioeciousness (selfing) 4. skewed sex rations 5. overlapping generations and age structured populations

Question 47

matrilineal most recent common ancestor -longest stretch of nonrecombining human mtDNA data -most recent common woman from whom all living humans descend in an unbroken line of mothers

Answer 47

mitochondrial (MRCA)

Question 48

patrilineal most recent common ancestor -longest stretch of nonrecombining DNA in the human genome -not as good at telling the story as the MRCA

Answer 48

y chromosome (PRCA)

Question 49

bottleneck in human evolution -one of the Earth's largest eruption -entire plant and worlds human population reduced -evidence: human genetic studies, pollen studies from Bay of Bengal, stratified Toba ash

Answer 49

Toba Supereruption (YTT)