Evolution 131 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

T/F: Theories of evolution are generally a very old science

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Explain original theory by Plato and Aristotle

A

“Cyclical stasis” - everything moved around in a cycle that repeated itself but in a “progressive way”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is one of the major ideals that prevent the forward movement of the science of evolution

A

The book of genesis/religion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Around what time did evolution start getting accepted?

A

1700s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When was Darwin’s model presented and when was it integrated?

A

1860s

1930s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What was Lamark’s evo therory? Give an example

A

Scala Naturae: organisms start at the bottom of a “escalator” and continuously take steps towards a more perfect form. There were multiple episodes of special creation
-Example- fish all become mammals and start at the same place but not all fish were related and created independently

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What was Cuvier’s evo theory?

A

Natural Theology ->Static Perfected Machines: organisms were built as adapted machines to their environment. Only way to get something new is to wipe out the existing and something new will be created in its place.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What was the ideal of Natural Theology?

A

the world was a “perfectly tuned machine” with everything in harmony with each other, no competition, no evolution
“A place for everything and everything in it’s place”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What was Darwin’s evo theory?

A

“natural selection” - world was in harsh competitive equilibrium. race of adaptation leads to both extinction and speciation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What was wrong with Darwin’s model at the time

A

It was not proveable at the time and went against the major church teaching which was powerful at the time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

______ is the central organizing concept in bio.

A

Evolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Evolution is based on the principles of what? and What does it operate on?

A

Genealogical continuity, variation, sorting by natural process
-all this operates on spatial and temporal scales to produce diversity and pattern.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Generally how would evolution be static under Darwin’s theory?

A

if a beneficial variation gets lost in the next generations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Pre-mendelian genetics assumed that features of parents were ____ in offspring leading to ____ of certain traits

A
  • blended

- dilution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Mendel showed that genes _________ across generations

A

retained their IDS across generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

novel phenotypes arise through what?

A
  • recombination (meisos-gametosis- alleles)

- mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

T/F: DNA is an unstable molecule subject to many factors

A

FALSE - it is relatively stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do mutations come about (in respect to DNA and nucelotide base-pairs)

A

errors in “coding’ aren’t caught and translated into genetic material (base subs, base insertions/deletions, inversions, duplications)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do mutations do in respect to chromosomes/loci?

A

moves gene segments or single/multiple loci within the chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does it mean that mutations aren’t truly random?

A

some loci have more of chance to have mutations but still has no significant impact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Mutations are random with respect to _____

A

adaptation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T/F: Most mutations are neutral/deleterious and rarely result with benefit

A

True!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How does the chance of a beneficial mutation occurring increase?

A

build up of neutral/nearly-neutral mutations acted on by GSE over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is gametogensis?

A

Process of meiosis where diplod cells divide to produce haploid gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What mixes up existing genetic variation/the existing gene pool of variation?

A

recombination (sex)

  • independent assortment
  • crossing over
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In reproduction, what is driving recombination forces produce the immense variation of gentotypes among gametes?

A
  • crossovers

- independent assortment of maternal/paternal chromatids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Fusion of gemetes of different individuals further increases ______

A

genetic diversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Where does recombination get its genetic info?

A

the pool of existing alleles (including conserved mutations)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What accounts for most of the genetic diversity of a population at a given time?

A

Recombination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the source of genetic variation?

A

MUTATIONS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How were mutations experimentally used?

A

to define gene actions and where they reside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the “classical” and “balanced” school of population genetic theory?

A

check handout

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

According to experiments that support the “balanced” school what percent of loci from studied organisms had 2 or more allelic forms? They were heterozygous from what percent of their loci?

A

20-85%

5-20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does the HW equilibrium tell us?

A

What the predicted frequencies of genes will be in the next generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does HW prove in respect to recombination?

A

sexual reproduction does not constantly drive evolution (alter genotype frequencies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

T/F: HW shows that no real evolution is going on

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the requirements for HW rule?

A
  • Pop size is infinite
  • equal sex ratios w/ random mating (no sexual selection)
  • no gene flow (immigration/emmigration of genotypes
  • no natural selection
  • no mutation or its canceled out
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

HW rules states that genotype freq will reach equilibrium state in _________

A

a single generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Why is HW still useful even though it never really happens?

A
  • “close enough” only a small sample is taken so there is a large buffer for error that covers up the effects of the violations
  • helps realized the violating factors are the mechanisms for evolution
40
Q

T/F: Most of the time loci DO NOT adhere to HW.

A

FALSE: most go along with HW predictions, only large events are detected

41
Q

What does it mean when HW has “no memory”

A

It only includes the genes in the pool that are present at the moment
-if genes are added/removed it will reach a new equilibrium in the next generation, disregarding any genes that existed before

42
Q

What are the random factors that drive evolution? (disturb H-W)

A

GSE
(founder effect, bottlenecking, drift)
Mutation (minor)

43
Q

What are the directional factors that drive evo?

A
Gene flow (not really
sexual selection
natural selection
44
Q

GSE is ____ related to population size

A

inversly

45
Q

What is GSE?

A

random effects that reduce the pool of existing genetic variation

46
Q

When does GSE usually occur?

A

When the population size is small that only a small set of genes can be expressed

47
Q

What are the subcategories of GSE?

A

Genetic drift is the title but is also broken down

  • Founder effect
  • Bottlenecking
48
Q

T/F: GSE strongly effects specific types of populations in specific situations?

A

FALSE: most natural pops are strongly effected (on a spatial and temporal scale)

49
Q

What is founders effect?

A

When a pop is established by a small number of colonists, those reproduce with only a small subset of genes and technically have lost variation present in the larger population and end up developing a different genetic code

50
Q

What is bottleneck effect?

A

Pop is reduced dramatically due to some effect and lots of genes and variation are lost and freq altered dramatically

51
Q

How can genes be re-introduced/restored?

A

Gene Flow - immigration of genes back into the population

52
Q

What aspect of evolution is an important counterbalance in microevolutionary dynamics? Why?

A

gene flow

  • it can restore genes lost for any reason and it “promotes” genetic homogeneity of populations
  • it can dull the effects of natural selection
53
Q

When is gene flow usually negated?

A

Geographic isolation

54
Q

What is gene flow?

A

the immigration and emmigration of individuals carrying/bringing in/out genes with them

55
Q

Speciation is tied to the negation of _____

A

gene flow

56
Q

What is the problem of gene flow on large population scales?

A

Its not able to counteract the genetic drive/structuring of populations created by natural selection and genetic drift

57
Q

HW is disrupted by what 4 factors?

A

mutation
genetic sampling error
gene flow
selection

58
Q

What out of the 4 HW violations alter allele freq at random?

A

GSE, mutation, GF

59
Q

Selection is oriented with respect to ______ and serves to counteract the influences of ____,___, and __.

A

adaptation

GSE mutation GF

60
Q

What is the prime driver in evolutionary change? why?

A

Selection

it diversifies organisms through promoting adaptation to divergent modes of life

61
Q

Selection is meaningless when it does not involved _____

A

genetic variation

62
Q

T/F: in variation, the variants are rarely ever equal in adaptive value

A

True!

63
Q

What is the expression for the relative difference in variation of individuals

A

fitness

64
Q

What is selection equal?

A

1- fitness (w)

65
Q

What are the three key aspects of the relation between fitness and selection

A

1) fitness is expressed in terms of reproductive success (with a allele or genotype)
2) selection OCCURS to INDIVIDUALS
3) selection happens anytime before the complete creation of the next individual (aka sperm/seeds affected as well)

66
Q

Why is fitness only expressed in terms of reproduction?

A

Non-survival matters only in its implications for reproduction (one who makes more with adequate genes is more fit than one with “better”genes and does without descendants)

67
Q

Does selection act or occur? To alleles or individuals?

A

OCCURS to INDIVIDUALS (mainly)

alleles = long term

68
Q

What are fitness components?

A

attributes that affect reproductive success in organisms

69
Q

Each fitness component is given a _____ which reflects

A

value that reflects relative reproductive success of any variant states

70
Q

The fitness of an individual is equal to _______ in a set of fitness components

A

the lowest value (in the set)

71
Q

T/F: Overall fitness can be measured directly

A

FALSE : its a prediction of the future using the measured appropriate fitness components of the present

72
Q

______ may stabilize, direct, or disrupt the existing pattern of genetic variation in a pop through time

A

selection

73
Q

Rate of evo change is dependent on (2 general things)

A
  • intensity of selection

- contributions of random influences (GSE, mutation, GF)

74
Q

Population size plays a critical role in defining the effects of _____, below a certain size ______ becomes too weak to direct evolutionary change

A

GSE

selection

75
Q

What is “stabilizing selection?”

A

fitness value and genotype freq distributions overlap

-the dominant mode where the general pop. reaches a moderate lv of adaptation to the environment.

76
Q

What is “directional selection”?

A

fitness values and genotype freq distributions are offset

-over time the offset will fall back into stability (normal things happening)

77
Q

What is “disruptive selection?”

A

directional selection where are multiple peaks in the distribution of fitness values; genotypes diverge and create “separate morphs”

78
Q

_____ is the consequence of indv differences in fitness

A

natural selection

79
Q

Fitness is a relative measure of ________ which depends on both ______ and the ______ at the given time.

A

individual (genotypical) reproductive success

  • genetic composition of the pop
  • state of environment
80
Q

T/F: if population or environment changes, fitness still remains the same

A

FALSE: it changes and can change multiple times in a lifetime

81
Q

Define adapataion

A

a feature (BPM) that improves ability to come with a physical/biotic environmental condition

82
Q

T/F: an adaptation is always the result of selection

A

True! they cannot be deleterious

83
Q

Adaptations are defined in reference to ____ and _____

A

the environment and others in the population

84
Q

What is the difference between fitness and adaptation? (refer to lect. 6 tables)

A

It is an absolute term, multiple individuals can have the same values for adaptation or many adaptations

85
Q

T/F: two individuals may have the same fitness values

A

FALSE: in terms of value one has to be at least slightly better in a certain fitness component

86
Q

T/F: only genotypes (alleles in long term) can have fitness

A

True!

87
Q

Adaptation of a pop or species is simply what?

A

the sum of the results of selection occurring at an individual level

88
Q

T/F: fitness and adaptation refer to the same things

A

FALSE

89
Q

Explain how a high fitness genotype can have low adaptation.

A

Birds with flamboyant colors to attract females also attract predators

90
Q

What is the mice example of high fitness but low adaptation? (double check with notes later)

A

Mice with Tt genes with “t” giving sperm that is better at fertilizing eggs but those born homozygous “tt” are fertile or die

91
Q

What is the “runaway” process?

A

when female sexual selection causes male attributes to be so extreme it reduces adaptation greatly to the environment

92
Q

Adaptive strategies of organisms depend on? (2 things)

A
  • how the organism perceives the environment

- predictability/stability of limiting resources

93
Q

What are fine and coarse grained species?

A
fine = uniform environment perceived
coarse = patchy environment perceived
94
Q

Fine grain species are generalist or specialists? Coarse grain?

A

generalist

specialist

95
Q

What conditions promote r-strategists? K-strategists?

A

unpredictable/unstable = r

opposite for K

96
Q

What strategy does predictable,unstable conditions promote

A

z-strategist

97
Q

What is z-strategist?

A

ones that have slowly diminishing populations that wait for better conditions to come back (double check this)