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midterm 1 Flashcards

1
Q

what are the 4 horsemen

A

selection, migration, mutation, drift

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2
Q

what are Darwins 4 postulates

A
  • there is variation
  • variation is heritable
  • more offspring are there than can survive/reproduce
  • survival and reproduction isn’t random and is effected by what traits an individual has
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3
Q

what are the classes of selection

A

fecundity: differences in reproduction success
viability: differences in survival success

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4
Q

what is the term for when the fitness of a phenotype becomes less common as genotype becomes more common

A

negative frequency dependent selection

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5
Q

what are the 2 types of mating

A

assortative: more likely to mate with similar looking individual
dissassortative: more likely to mate with someone less similar

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6
Q

does natural selection act directly on traits

A

no

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7
Q

what is genetic drift

A

change in allele frequency due to chance

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8
Q

what are the causes of drift

A

continuous drift
population bottleneck
founder effect

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9
Q

what is a population bottleneck

A

sudden decrease in population size

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10
Q

are the effects of drift bigger in bigger/smaller populations

A

smaller

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11
Q

what is fixation

A

change in gene pool to multiple alleles to just one

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12
Q

where is fixation fastest

A

smaller populations

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13
Q

what is heterozygosity

A

possession of 2 different alleles

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14
Q

where is heterozygosity maximized

A

when allele frequencies are similar

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15
Q

what is Ne

A

effective population size

the population of individuals that contribute alleles to next generation

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16
Q

what is ne effected by

A

number of adults, sex ratio, fluctuations over time

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17
Q

what do things that suppress Ne make the population be

A

genetically smaller than it looks

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18
Q

what are the types of variation

A 
genetic variations (vg)
environmental variation (ve)
genotype by environment variation (vge)
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19
Q

how many mutations come from male germ line mutations

A

2/3

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20
Q

what are the types of mutation

A

point mutation, insertion, deletion, inversion, chromosome fusion, aneuploidy, polyploidy

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21
Q

what is a nonsense mutation

A

mutation that introduces a premature stop codon

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22
Q

what is a non-synonymous substitution

A

mutation that changes amino acid coded for

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23
Q

what is a synonymous substitution

A

mutation that keeps amino acid coded for the same

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24
Q

how many is the average germ-line mutation rate

A

1.0x10^-8

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25
what is a indictable defence
response activated only when needed
26
what is an intron/ exon
intron is area before coding region (exon)
27
what is cnv
where sections are repeated and number of repeats varies between individuals
28
are more mutations a result of cnv or point mutations
cnv
29
what is dn/ds > 1
advantageous
30
what is dn/ds < 1
deleterious
31
what is dn/ds=1
neutral
32
how to neutral mutations fluctuate
via drift
33
what is a substitution
replacement of one allele for another as predominant allele
34
what does neutral theory state
neutral mutations that rise due to fixation by drift outnumber benefical mutations that get selected for and substitute so drift if predominant evolutionary mechanism so rate of evolution = neutral rate
35
what is issue with neutral theory
neutral mutation rate should vary among species and go off generation time not clock time
36
what is nearly neutral theory
species with large populations tend to have small populations and vice versa - so as generation time goes up, population and therefore 2NeS goes down - this makes it so they balance out as in large populations mutations are selected against - and in small populations more mutations are subjected to drift
37
what is neutral theory a null hypothesis for
if natural selection caused the evolution
38
what is neutral mutation rate = neutral substitution rate captured by
synonymous mutation rate
39
what is codon bias biased towards
for codons associated with abundant species of tRNA making it more efficient
40
what is a monophyletic group
a clade | node and all its descendants
41
what is a polytomy
node on phylogeny with more than 2 descendant lineages
42
what is a paraphyletic group
contains node but not all descendants
43
what is a polyphyletic group
when 2 lineages convergently evolve similar traits
44
what is an apomorphy
trait unique to a species/group
45
what is a pleisiomorphy
ancestral trait
46
what is analogy
similarities due to convergent evolution
47
what is homology
similarities due to common ancestor
48
what is Homoplasy
similarities due to convergent evolution
49
what are synapomorphies
similarities from common ancestor, but only in a subset of the species
50
what are symplesiomorphies
plesiomorphies shared by two or more taxa
51
is an out group or any species on the tree ancestral?
nope
52
what are the different ways alleles affect phenotypes
dominance, epistsasis, pleiotropy, and plasticity
53
what is epistasis
effect of mutation dependent on on the presence/absence of another mutation
54
what is pleiotropy
when one gene influences multiple seemingly unrelated traits
55
what is codominance
when both alleles in genotypes are in phenotype
56
what is incomplete dominance
both parents genotypes blend into a new phenotype
57
what is mosaic evolution
evolution of different parts of organism at different rates
58
what is mutation selection balance
new copies of allele keeps mutating allowing it to persist at low frequencies
59
what is the speed of fixation/increase in frequency for new dominant alleles
increase in frequency fast | fixate slowly
60
what is the speed of fixation/increase in frequency for new recessive alleles
increase in frequency slow | once common fixate fast
61
what are the hardy Weinberg equilibrium assumptions about a population
``` allele frequencies in a population are constant when there's: no mutation no migration random mating large population no selection ```
62
what is migration
movement of alleles between populations
63
what is the effect of migration
immediate change in allele frequency of recipient population
64
what happens with migration in absence of selection
migration homogenizes allele frequencies across populations

Evolution (8 decks)

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