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bio 220 > week 3 vocab > Flashcards

week 3 vocab Flashcards

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Biology 101 flashcards
1
Q

example of organisms with sex roles reversed

A

jacanas or seahorse

male incubates egg (more energetically invested), female compete and are more aggressive

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2
Q

sexual selection occurs when:

A

there’s a heritable variation of a trait that influences mating success or fertilization success

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3
Q

which sex often experiences stronger sexual selection?

A

the competing sex,

logic: non-competing can get with whoever they want, but competing one is limited. there’s more selective pressure on the limited one

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4
Q

elaborate traits usually occur in the ___ sex

A

competing

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5
Q

sexual selection can occur:

A

before or during/after sex

intrasexually or intersexually

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6
Q

example of intrasexual selection before mating

A

mooses

male-male or female-female competition for access

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7
Q

example of intersexual selection before sex

A

peacocks

display by competing sex for mating choice by non-competing sex

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8
Q

example of intrasexual selection d/a sex

A

frogs

compete to have their sperm fertilize egg

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9
Q

example of intersexual selection d/a sex

A

“cryptic mate choice”

female chicken can choose which sperm fertilizes their egg

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10
Q

intrasexual selection

A

individuals within a sex compete DIRECTLY for access to mates and their gametes

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11
Q

examples of evolution of traits for intrasexual selection

A

weaponry, fast sperm, sexual size dimorphism (competing sex is larger)

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12
Q

sexual size dimorphism

A

competing sex is larger

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13
Q

intersexual selection

A

indirect competition for access to mates and their gametes

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14
Q

what traits can help intersexually selecting organisms win access to mates?

A

mating displays and signals, courtship behavior, or genitalia

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15
Q

sexual selection is the result of:

A

direct or indirect competition for mates

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16
Q

benefits of sexual reproduction must ___ ___ ___

A

overcome non-trivial costs

pros of only passing on 1/2 of genetic material must be better than cons of potentially risking survival (colors of guppies finding balance between mating visibility and predation avoidance)

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17
Q

sexual selection often results in traits that ___ natural selection

A

oppose

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18
Q

where does natural variation come from?

A

mutations!

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19
Q

process of including mutation in population

A

created, generates alleles, natural selection hopefully favors it, adaptive trait selected

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20
Q

selection ___ ___ ___

A

edits existing variation

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21
Q

genes are:

A

composed of DNA and specify how to build proteins

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22
Q

what are mutations caused by?

A

DNA copying errors, chemicals, or ionizing radiation

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23
Q

what is important about ionizing radiation?

A

it can’t affect gametes!

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24
Q

frequencies of mutations can change due to:

A

meiosis/recombination, natural selection, genetic drift, or gene flow

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25
Q

mechanisms that DECREASE variation

A

stabilizing selection, inbreeding, and genetic drift

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26
Q

“silent” or “synonymous” mutations

A

don’t change the amino acid

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27
Q

“nonsynonymous” mutations

A

change the amino acids and potentially the function of the following protein, can then be acted upon by NS

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28
Q

what are the structural mutations that can occur?

A

deletion, duplication, inversion, fission, or fusion

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29
Q

mutation rates are very low! so…

A

mutations likely won’t change allele frequencies in one generation

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30
Q

recombination during meiosis can…

A

exchange maternal and paternal chromosomes to produce new combinations more rapidly

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31
Q

what is the molecular clock?

A

Kimura’s theory that most mutations are neutral

we accumulate mutations constantly and we can use that to date how long ago different populations diverged

a lot of DNA isn’t used much (has since been disproven) and mutations of third codon don’t always have an impact

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32
Q

phenotypic plasticity

A

a change in an individual’s PHENOTYPE in response to their environment

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33
Q

natural selection example:

A

soapberry bugs

introduction of new host plants with different fruit sizes, bugs shifted hosts

NS resulted in beak adaptation to reach seed

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34
Q

what are the types of selection?

A

directional, disruptive, and stabilizing

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35
Q

directional selection

A

individuals with one extreme heritable trait are favored over others

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36
Q

example of directional stabilization

A

Darwin’s finches in the drought

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37
Q

stabilizing selection

A

individuals with intermediate trait are favored

38
Q

example of stabilizing selection

A

gall-making flies

larvae produce galls on goldenrod plants, but large and small galls were targeted by predation, so intermediate size was favored

39
Q

disruptive selection

A

individuals at either extreme of a phenotype are favored

40
Q

example of disruptive selection

A

african seedcrackers (birds)

small beaks can eat soft seeds, large can eat hard, but medium aren’t optimal for either

41
Q

what does stabilizing selection do?

A

maintain mean and reduce variance

42
Q

what does disruptive selection do?

A

maintain mean and increase trait variance

43
Q

what does directional selection do?

A

change mean and potentially reduce trait variation

44
Q

sexual selection

A

selection due to within-population competition for access to mates and their gametes

45
Q

sexual selection is responsible for:

A

more diverse and extravagant traits in nature, rapid evolution, and increased speciation

46
Q

anthropomorphism

A

attributing human traits or intentions to non-human entities

innate tendency that we should avoid with this content

47
Q

sexual selection occurs as a result of ___

A

variation in mating success

not everyone gets to mate or the same amount of mates

48
Q

what causes variations in mating success?

A

competition

49
Q

gametes are the ____

A

main difference between males in female

50
Q

egg

A

large and sessile gametes

51
Q

sperm

A

small and mobile gamete

52
Q

sexual possibilities:

A

none (no gametes), two separate sexes (lions), hermaphroditism, sequential hermaphroditism

53
Q

hemaphroditism

A

male and female gametes are produced in the same individual

common in plants

54
Q

sequential hermaphroditism

A

individuals start life as one sex and later transition into the other

55
Q

sex roles

A

dependent on differences in parental investment between the sexes

56
Q

higher parental investment ->

A

limiting sex, has mating preferences

57
Q

lower parental investment

A

limited sex, has mating competition

58
Q

anisogamy

A

differences in gamete size

59
Q

our ancestral state is ___

A

isogamy

60
Q

isogamy

A

single mating type, everyone can mate with everyone else

all gametes same size

universal compatibility

61
Q

gamete trade-offs

A

large but slow/non-moving gamete with lots of resources vs. small but faster gamete with little resources

62
Q

anisogamy is ___ distributed

A

disruptively

63
Q

Bateman’s principle

A

in most species, females invest more in reproduction than males, making them the limiting sex

64
Q

male lifetime fitness is limited by…

A

how many mates they can obtain

65
Q

female lifetime fitness is limited by…

A

how much resources they have available to allocate reproduction

66
Q

result of Bateman’s principle?

A

females can be the more choosy sex and males have to compete for them

roles can be reversed!

67
Q

can phenotypic plasticity evolve?

A

yes, it can be an adaptation

ability to get fit more efficiently is heritable, but looking fit is not a heritable trait

68
Q

reaction norm

A

range of phenotypic expressions of genotype across range of environments

69
Q

example of phenotypic plasticity

A

male horned beetles

use horns and body size to fight for females

morphology determined by amount of food in larval period (small horns and body or large horns and body)

why spend resources on large horns with small body if you’ll lose anyways?

70
Q

common garden experiment

A

individuals with different phenotypes are grown under same conditions

71
Q

genetically controlled in CGE if…

A

individuals maintain their wild traits

72
Q

phenotypic plasticity in CGE if…

A

individuals shift to similar traits

73
Q

what is the purpose of common garden experiment?

A

distinguishing genetic variation from phenotypic plasticity

74
Q

what are mechanisms that maintain genetic variation?

A

meiosis/recombination, natural selection, gene flow, disruptive selection, negative frequency-dependent selection

75
Q

mechanisms that decrease genetic variation

A

stabilizing selection, inbreeding, genetic drift, positive frequency-dependent selection

76
Q

frequency dependent selection

A

fitness of individual is dependent on its relative frequency amongst the population

77
Q

positive frequency-dependent selection

A

majority phenotype wins, reduces genetic variation in population

78
Q

example of positive frequency-dependent selection

A

poisonous butterflies favoring locally common butterflies of other poisonous ones

79
Q

mullerian mimicry

A

two poisonous species mimic each other

whatever looks like this won’t get eaten

80
Q

negative frequency-dependent selection

A

minority phenotype wins, promotes genotypic and phenotypic variation in population

81
Q

example of negative frequency-dependent selection

A

purple/yellow morph flowers

naive pollinators will switch between then as they find new reward (nectar/pollen)

82
Q

sampling effects

A

changes in allele frequency over time that are random with respect to their function or selection

83
Q

founder effect

A

loss of genetic diversity bc of migration even in which smaller group “founds” their own population

84
Q

example of founder effect

A

less genetic diversity as humans spread out from Africa

85
Q

bottleneck effects

A

loss of genetic variation from dramatic reduction in population size and then recovery from it, new population descends from small number

86
Q

example of bottleneck effect

A

northern elephant seals

hunting reduced population to 20-40 individuals, today have extremely low genetic variation

87
Q

genetic drift

A

changes in allele frequencies in population due to chance events

88
Q

random effects can lead to…

A

differences in numbers, sex ratio, or survival of offspring

89
Q

genetic drift leads to…

A

evolution at random

90
Q

example of genetic drift

A

beetles being crushed by shoe images

91
Q

4 conclusions about genetic drift

A

its unbiased, affects smaller populations more, decreases genetic diversity over time, and generates divergence among populations

imagine plots of multi-colored lines

bio 220 (10 decks)

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