Unit 1 terms Flashcards

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1
Q

natural selection

A

a mechanism of evolution that favors heritable traits that increase an organism’s chance of survival and reproduction

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2
Q

fitness

A

the ability of an individual to successfully reproduce

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3
Q

evolution

A

change in the genetic composition of a population over time

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4
Q

adaptation

A

an increase in fitness due to evolution

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5
Q

genotypes

A

the specific genes of a trait

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6
Q

phenotypes

A

how the trait is actually presented

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7
Q

Natural Theology

A

Earth is young; everything is according to the Scala Naturae; species don’t change

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8
Q

catastrophism

A

change occurs randomly
* fossil records

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9
Q

uniformitarianism

A

change is uniform

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10
Q

Lamarck

A

spontaneous generation produces species that evolve over time due to 1. drive towards complexity 2. adaptive force (giraffe neck example)

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11
Q

Malthus

A

populations increase over time; food production can’t keep up; not everyone can survive

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12
Q

On the origin of species

A

famous publication by Darwin in 1859

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13
Q

hypothesis

A

testable prediction

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14
Q

theory

A

strongly supported explanation, often deemed fact

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15
Q

law

A

specific prediction derived from a broader theory

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16
Q

evolution occurs on a level of ___

A

population

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17
Q

3 conditions for evolution by natural selection

A
  1. variability among species
  2. traits are heritable
  3. difference in survivability
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18
Q

comparative study

A

compare populations from naturally-differing environments

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19
Q

experimental study

A

actively manipulate the population or environment to create differences

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20
Q

common-garden experiment

A

bring samples of populations into the same lab to grow under the same conditions

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21
Q

know the bacterial resistance example

A

some bacteria had a mutation that made them resistant to an antibiotic – these bacteria could survive and reproduce more

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22
Q

transitional species

A

transitional forms of species will be found in past or current populations (ex. whales)

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23
Q

biogeography

A

species in closer geographic proximity should be more closely related when species cannot easily disperse

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24
Q

taxonomic relationships

A

species that diverged more recently share more features than those that diverged longer ago

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25
Q

homologous and vestigial traits

A

complex structures and functions cannot appear from nothing, but must evolve from existing structures (ex. limb bones in terrestrial vertebrates)

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26
Q

adaptation vs. acclimation

A

adaptation: long-term evolutionary change in response to a changed environment
acclimation: short-term adjustment to a changed environment

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27
Q

evolution is not ________

A

PROGRESSIVE; species may become more/less complex or gain/lose traits (use derived)
ex. flightless birds from flighted birds

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28
Q

what is wrong with acting “for the good of the species”

A

there is no objective “good” for a species; there is no target for how evolved a species needs to be

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29
Q

vestigial traits

A

traits that have lost their function in a particular species

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30
Q

Hardy-Weinberg principle

A

allele and genotype frequencies will remain constant from one generation to the next without evolutionary conditions (use allele frequencies to predict genotype frequencies)

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31
Q

Hardy-Weinberg conditions

A
  1. no natural selection
  2. no genetic drift
  3. no gene flow
  4. no new mutations
  5. random mating
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32
Q

assortative mating

A

mates are chosen for their similarity (+) or dissimilarity (-) to self

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33
Q

positive assortative mating ex.

A

mating for height (two tall people mate)

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34
Q

negative assortative mating ex.

A

mating for MHC (women preferred men who smelled different to them)

35
Q

inbreeding

A

increases the number of homozygous recessive deleterious alleles – reduces fitness

36
Q

sexual selection

A

when individuals differ in their ability to obtain
mates based on phenotype

37
Q

INTERsexual selection (female choice)

A

females choose their mate based on visual indicators of fitness or resources (ex. a male spider that offers more food)

38
Q

INTRAsexual selection (male-male competition)

A

male traits that help them compete with other males are favored; males compete for access to females (ex. elephant seals fighting for beach territory)

39
Q

sexual dimorphism

A

when there are drastic differences in phenotypes of different sexes; females must be selective with their eggs

40
Q

Mendelian inheritance

A

biological inheritance pattern

41
Q

allele

A

different versions of a gene

42
Q

locus

A

a specific place on a chromosome

43
Q

gene pool

A

the combination of all the genes (including alleles) present in a reproducing population or species

44
Q

genetic drift

A

changing of allele frequency within a population due to chance
* affects small populations greatly
* is more effective over longer periods

45
Q

bottleneck effect

A

populations that drop greatly in size are likely to experience drift

46
Q

founder effect

A

reduction in genetic variability when a small group gets separated from their original population

47
Q

fixation

A

complete loss of an allele

48
Q

gene flow

A

transmission of alleles across populations

49
Q

source/sink populations

A

source population to the sink population

50
Q

directional disruption

A

favors one end

51
Q

stabilizing disruption

A

favors intermediate

52
Q

disruptive selection

A

favors both ends

53
Q

balancing selection

A

favors less common form

54
Q

heterozygote advantage

A

when someone with the heterozygote gene has a fitness advantage over someone with a homozygous gene (sickle cell and malaria)

55
Q

fundamental asymmetry of sex

A

females invest a lot more resources into their offspring than males do

56
Q

morphological species

A

how similar they look (allows us to use fossils)

57
Q

biological species

A

whether or not they can produce offspring

58
Q

phylogenetic species

A

share a common ancestor and have derived traits

59
Q

allopatric speciation

A

speciation through physical separation

60
Q

colonization

A

when a species inhabits a new area

61
Q

vicariance

A

geological event that separates a species

62
Q

sympatric speciation

A

speciation of a species that occupies the same geographic area due to disruptive selection or polyploid mutants

63
Q

fusion

A

when separated species remix after limited independent evolution has occurred

64
Q

stable hybrid zone

A

when hybrids only survive well within their specific region

65
Q

reinforcement

A

when hybridization produces offspring that are less fit

66
Q

mutation

A

mostly detrimental, sometimes beneficial
* least likely to occur over other evolutionary factors
* completely random

67
Q

tips

A

end of a branch; represents a species

68
Q

branches

A

a line representing a species through time

69
Q

nodes

A

fork; a point in a tree where a branch splits into two or more branches; represents the most recent common ancestor

70
Q

synapomorphy

A

a trait found in two or more taxa that is present in their MRCA but missing in distant ancestors

71
Q

homoplasy

A

when the same trait evolves independently in different species

72
Q

homology

A

shared traits due to common ancestry

73
Q

convergent evolution

A

independent evolution of similar traits in unrelated organisms due to adaptation to similar environments

74
Q

radiometric dating

A

using the half-lifes of radiometric elements to determine the age of a fossil

75
Q

molecular clock

A

measures the number of genetic changes in a species over time (works well with organisms that don’t fossilize well)

76
Q

Precambrian era

A

4600-540 mya
* formation of Earth
* first prokaryotic life
* oxygenated atmosphere

77
Q

Paleozoic era

A

540-250 mya
* first animals
* first plants
* first arthropods

78
Q

Mesozoic era

A

250-65 mya
* dinosaurs
* mammals
* birds
* flowering plants

79
Q

Cenozoic era

A

65-0 mya
* primates
* apes
* humans

80
Q

Cambrian explosion

A

rapid diversification of animals

81
Q

adaptive radiation

A

rapid diversification of an evolutionary group
* can be due to 1) ecological opportunity or 2) development of a key trait

82
Q

key adaptation

A

a new feature that greatly improves the evolutionary potential of a group

83
Q

Cretaceous-tertiary extinction (KT)

A
  • end of Mesozoic
  • loss of dinosaurs, many reptiles
84
Q

Permian-Triassic

A
  • between Paleozoic and Mesozoic
  • mother of mass extinctions