Unit 4 lectures

Question 1

sources of phenotypic variation

Answer 1

environmental and genetic

Question 2

quantitative phenotypic variation

Answer 2

continuous traits that can be measured, ex. tail length

Question 3

qualitative phenotypic variation

Answer 3

discrete character states or categories, ex. tail color

Question 4

genetic variation

Answer 4

diffs in alleles within a popl

Question 5

sources of genetic variation

Answer 5

rearrangement of existing alleles, mutations producing new alleles

Question 6

microevolution

Answer 6

changes in allele frequency within popl over time

Question 7

population genetics

Answer 7

study of properties of genes in popl

Question 8

how do we measure genetic variation

Answer 8

single-nucleotide polymorphisms

Question 9

what does the hardy-weinberg principle predict

Answer 9

genotype frequencies

Question 10

criteria of HW-equilibrium

Answer 10

1. no mutation
2. no gene flow or genetic drift
3. random mating
4. large popl size
5. no natural selection

Question 11

what is the concl if all 5 assumptions for HW eq. are true

Answer 11

allele and genotype frequencies don’t exchange from one gen to next

Question 12

agents of evolutionary change

Answer 12

mutation, gene flow, nonrandom mating (assortative and disassortative)

Question 13

assortative mating

Answer 13

phenotypically similar individuals mate, increases prop of homozygous individ

Question 14

disassortative mating

Answer 14

phenotypically diff individ mate, produces excess of heterozygotes

Question 15

founder effect

Answer 15

one/few individ disperse and become founders of new, isolated popl

Question 16

bottleneck effect

Answer 16

drastic reduction in popl size due to natural disasters, loss of genetic variability

Question 17

what is the diff between natural selection and evolution

Answer 17

natural selection is a process; evolution is historical record of change thru time

Question 18

selection to match climatic conditions

Answer 18

enzymes can function differently at diff temps

Question 19

what is the most fit phenotype

Answer 19

the one that produces greatest number of offspring

Question 20

intrasexual selection

Answer 20

competitive interactions between members of one sex

Question 21

intersexual selection

Answer 21

mate choice

Question 22

secondary sexual characteristics

Answer 22

antlers and horns used to combat other males; long tail feathers and bright plumage to persuade members of opp sex

Question 23

sexual dimorphism

Answer 23

diffs between sexes (males larger than females)

Question 24

sperm competition

Answer 24

selects for features that increase probability that male’s sperm will fertilize eggs

Question 25

handicap hypothesis

Answer 25

only genetically superior mates survive w handicap (long tail w hinderance in flying)

Question 26

sensory exploitation

Answer 26

evolution i males of signal that exploits preexisting biases

Question 27

frequency-dependent selection

Answer 27

fitness of phenotype depends on frequency within popl

Question 28

negative frequency-dependent selection

Answer 28

rare phenotypes favored by selection

Question 29

positive frequency-dependent selection

Answer 29

favors common phenotype, eliminates variation

Question 30

oscillating selection

Answer 30

selection favors one phenotype at one time and another phenotype at another time, maintain genetic variation in popl

Question 31

heterozygote advantage

Answer 31

heterozygotes favored over homozygotes, maintain both alleles in popl

Question 32

how does heterozygote advantage affect sickle cell anemia

Answer 32

homozygotes for sickle cell allele usually die before reproducing; heterozygotes don't suffer anemia and are much less susceptible to malaria

Question 33

disruptive selection

Answer 33

eliminate intermediate types

Question 34

directional selection

Answer 34

eliminate one extreme, occurs when enviro changes

Question 35

stabilizing selection

Answer 35

acts to eliminate both extremes, makes intermediate more common ex. infant human w intermediate weight at birth have highest survival rate

Question 36

gene flow can be ___ or ____

Answer 36

constructive; constraining

Question 37

population

Answer 37

groups of individ in one place and time

Question 38

major characteristics of popl

Answer 38

geographic range, habitat, density, size, age structure, sex ratio, generation time

Question 39

most species have ____ geographic range

Answer 39

limited

Question 40

random spacing

Answer 40

individ don't interact strongly w one another, not common

Question 41

uniform spacing

Answer 41

individ more widely separated from each other, resource comp, behavioral interactions

Question 42

clumped spacing

Answer 42

uneven distribution of resources, common in nature

Question 43

metapopulations

Answer 43

occur in areas which suitable habitat is patchily distributed and separated by stretches of unsuitable habitat

Question 44

source-sink metapopls

Answer 44

popl in better areas boost popl in poorer areas

Question 45

number of births directly related to ______

Answer 45

number of females

Question 46

generation times

Answer 46

avg interval between birth of individ and birth of offspring

Question 47

2 factors affect life history

Answer 47

how long an individ lives, how many young it produces each year

Question 48

age at first reproduction correlates with ___

Answer 48

life span

Question 49

long-lived species ___ reproduction

Answer 49

delay

Question 50

short-lived species reproduce ____

Answer 50

early

Question 51

biotic potential

Answer 51

no limits on popl growth

Question 52

carrying capacity, K

Answer 52

max number of individ enviro can support

Question 53

if popl size equals carrying capacity, ___

Answer 53

growth rate = 0

Question 54

Allee effect

Answer 54

positive feedback, growth rates increase w popl size

Question 55

when resources are limited, cost of reproduction is ____

Answer 55

high

Question 56

K-selected popls

Answer 56

adapted to thrive when popl is near carrying capacity

Question 57

r-selected popl

Answer 57

selection favors individ w highest reproductive rates

Question 58

for human popl: birth rate ____; death rate _____

Answer 58

unchanged; fallen dramatically

Question 59

why are r-selected species adapted to function well in changing enviros

Answer 59

short generation times, produce numerous offspring in single reproductive event

Question 60

K-selected species thrive in more stable enviros bc

Answer 60

long generation times, produce offspring repeatedly during lifetimes

Question 61

Type I or II survivorship

Answer 61

offspring receive substantial parental care

Question 62

Type III survivorship

Answer 62

offspring receive little to no parental care

Question 63

what is a community characterized by

Answer 63

species richness, primary productivity

Question 64

ecotones

Answer 64

places where enviro changes abruptly

Question 65

niche

Answer 65

total of all ways an org uses resources of its enviro ex. space, food, temp range, mating conditions

Question 66

interspecific competition

Answer 66

when 2 species attempt to use same resource when not enough resource to satisfy both

Question 67

interference competition

Answer 67

physical interactions over access to resources

Question 68

exploitative competition

Answer 68

consuming same resources

Question 69

competitive exclusion

Answer 69

2 species competing for limited resource, species that uses the resource more efficiently will eliminate the other species

Question 70

how do plants adapt to predation

Answer 70

evolve mechanisms to defend themselves ex. chemical defenses: secondary compounds

Question 71

batesian mimicry

Answer 71

mimics look like distasteful species

Question 72

mullerian mimicry

Answer 72

resemble poisonous species

Question 73

predation _____ competition

Answer 73

reduces

Question 74

keystone species

Answer 74

species that manipulate enviro to create new habitats for other species ex. beavers and dams