Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOL 214 > Multilocus Evolution > Flashcards

Multilocus Evolution Flashcards

(74 cards)

Start Studying
1
Q

What does multilocus evolution explore?

A

The interactions between multiple genes that influence evolutionary processes

It acknowledges that organisms are complex systems where genes interact with each other and the environment.

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

What is the difference between single-locus and multilocus models?

A

Single-locus models study one gene, while multilocus models consider interactions among multiple genes

Multilocus evolution provides a more realistic understanding of genetic interactions.

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

Define epistasis.

A

When the product of one gene interacts with the product of another gene or with DNA itself.

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

What are polygenic traits?

A

Traits influenced by multiple genes.

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

What is pleiotropy?

A

One gene influences multiple phenotypic traits.

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

What is a haplotype?

A

The multilocus genotype of a chromosome or gamete; also known as the gametic phase.

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

Define linkage disequilibrium (LD).

A

The non-random association of alleles at two or more loci.

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

What does linkage refer to in genetics?

A

The association of two or more loci on a chromosome with limited recombination between them.

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

What is recombination?

A

The process by which genetic material is broken and joined to another DNA molecule.

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

What is homologous recombination?

A

Exchange of nucleotide sequences between two similar or identical strands of DNA.

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

What is the recombination rate?

A

The proportion of gametes that are recombinant, ranging from 0 to 0.5.

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

What indicates the presence of linkage disequilibrium?

A

The frequency of an allele at one locus is dependent on the genotype at another locus.

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

Define linkage equilibrium.

A

Given an allele frequency of p at locus A, that allele will have a frequency of p for any given allele at locus B.

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

How can haplotype frequency be calculated in linkage equilibrium?

A

By multiplying the frequencies of the constituent alleles.

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

What is the formula for the coefficient of linkage disequilibrium (D)?

A

D = f_{AB}f_{ab} - f_{Ab}f_{aB}.

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

What does a D value of 0 indicate?

A

Linkage equilibrium.

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

What is the maximum value of D?

A

0.25 when AB and ab are the only chromosomes present and at equal frequency.

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

What are some causes of linkage disequilibrium?

A
  • Selection
  • Mutation
  • Population admixture (gene flow)
  • Genetic drift
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What factors do not cause linkage disequilibrium?

A
  • Physical linkage
  • Inbreeding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the effect of recombination on linkage disequilibrium?

A

Recombination reshuffles genetic variation among loci, breaking down LD.

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

What is Hardy-Weinberg equilibrium?

A

Genotype frequencies are restored to equilibrium values after one generation of random mating.

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

How does selection affect allele frequencies in linkage disequilibrium?

A

Selection favoring allele A can cause a decline in the frequency of allele B, even if B is not under selection.

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

What is heritability?

A

The fraction of the total phenotypic variation in a trait that is due to variation in genes.

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

What is the formula for broad-sense heritability (H^2)?

A

H^2 = V_G / V_P.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is narrow-sense heritability (h^2)?
h^2 = V_A / V_P.
26
What does the breeder's equation (R = h^2S) predict?
The response to selection (R) is the difference between the mean phenotypic value of offspring and the parental generation before selection.
27
What are the types of selection?
* Directional Selection * Stabilizing Selection * Disruptive Selection
28
What is Hamilton’s Rule?
An allele for altruistic behavior will spread if Br - C > 0.
29
What is adaptation in evolutionary biology?
A trait that increases the fitness of its possessor, relative to those without the trait.
30
What methods are used to test for adaptation?
* Demonstrate the function of the trait * Demonstrate that the trait is linked to fitness
31
What is phenotypic plasticity?
When the same genotype produces different phenotypes, depending on environmental circumstances.
32
Define life history evolution.
The study of the timing of events during the life span of organisms and the associated fitness trade-offs.
33
What is the significance of energy allocation in life history evolution?
It drives differences in how energy is allocated to reproduction, metabolism, and growth.
34
What is the primary focus of life history questions?
The age at which sexual maturity is reached, reproduction frequency, lifespan differences, optimal offspring production rate, and egg size variation. ## Footnote Life history questions investigate the trade-offs in reproduction and survival strategies among different species.
35
How do species differ in the age at which sexual maturity is reached?
Species exhibit variations in the timing of sexual maturity based on their evolutionary strategies and environmental factors.
36
Why do some species only reproduce once?
Certain species may have evolved to invest all resources in a single reproductive event to maximize offspring survival.
37
What is Lack's Hypothesis?
Selection favors the 'clutch size' that produces the highest offspring survival, with survival probability decreasing as clutch size increases.
38
What is the trade-off in optimal offspring size?
An individual can produce many small offspring (few resources per offspring) or a few large offspring (many resources per offspring).
39
What is sexual selection?
A form of natural selection arising from differential reproductive success due to variation in mating success.
40
What does Bateman's experiment demonstrate?
Male reproductive success increases linearly with the number of mates, while female reproductive success plateaus after one or two mates.
41
What is the Bateman Gradient?
A selection gradient for mating success, indicating the relationship between the number of mates and fitness.
42
What does a high variance in mating success indicate?
It signals the presence of sexual selection.
43
What is anisogamy?
The difference in size or form between male and female gametes (eggs and sperm).
44
What is parental investment according to Robert Trivers?
The sex that invests more in offspring production and rearing will likely experience weaker sexual selection.
45
What is the difference in fitness limitation between the sexes?
The sex with a steeper Bateman gradient is limited by the number of mates, while the other is limited by the quality of mates.
46
What are the two mechanisms of obtaining mates?
* Intrasexual selection * Intersexual selection
47
What is sexual dimorphism?
Differences between the sexes that do not directly participate in reproduction, such as body size or coloration.
48
What is multilocus evolution?
The study of how interactions between multiple genes influence evolutionary processes.
49
What is epistasis?
When the product of one gene interacts with the product of another gene.
50
What does a coefficient of linkage disequilibrium (D) measure?
The degree of association between alleles at two loci.
51
What causes linkage disequilibrium?
* Selection * Mutation * Population admixture * Genetic drift
52
What breaks down linkage disequilibrium?
Recombination reshuffles genetic variation among loci.
53
What is speciation?
The evolutionary process by which new biological species arise.
54
Define sympatric speciation.
The evolution of two or more new species from a single ancestral species while inhabiting the same geographic region.
55
What is cladogenesis?
The origin of a new evolutionary lineage; the 'splitting of lineages.'
56
What is hybridization?
Mating between individuals from genetically distinct but closely related populations or species.
57
What is reinforcement in the context of speciation?
Natural selection that strengthens prezygotic isolation to prevent hybridization.
58
What is introgression?
The transfer of alleles from one species to another through hybridization.
59
What are the challenges of documenting allopatric speciation in the fossil record?
It is difficult due to the need for separate populations to be studied over the same temporal sequence.
60
What is the sister taxa debate?
The discussion on whether the sister taxon to humans is the chimpanzee or the gorilla.
61
What is the Sister Taxa Debate?
The debate over whether the sister taxon to humans is the chimpanzee or the gorilla. ## Footnote DNA sequence analyses using some markers suggest chimpanzees, while others suggest gorillas.
62
What is a Gene Tree?
A phylogenetic tree that traces the evolutionary history of a single gene. ## Footnote Gene trees can differ from species trees due to various evolutionary factors.
63
What is a Species Tree?
A phylogenetic tree that represents the evolutionary history of a group of species. ## Footnote Understanding species trees is crucial for interpreting evolutionary relationships.
64
What is Discordance in evolutionary trees?
The difference between gene trees and species trees due to factors like incomplete lineage sorting, gene duplication, and horizontal gene transfer. ## Footnote These factors can lead to varying interpretations of evolutionary relationships.
65
Define Synteny.
Similar gene order among humans, chimps, and gorillas. ## Footnote Synteny indicates evolutionary relationships among species.
66
How much does mitochondrial DNA differ between humans and chimpanzees?
Approximately 10%. ## Footnote This difference highlights the genetic divergence between the two species.
67
How much does nuclear DNA differ between humans and chimpanzees?
Approximately 1-2%. ## Footnote This close genetic similarity indicates a recent common ancestor.
68
What are the taxonomic implications regarding hominids?
Debate on whether hominids should be placed in the same genus as chimps and gorillas. ## Footnote This discussion is influenced by genetic similarities and evolutionary history.
69
What is the significance of extinct hominids?
All hominid lineages except Homo have gone extinct. ## Footnote This highlights the uniqueness of the human lineage.
70
What does coexistence refer to in the context of hominids?
Some hominid lineages coexisted at the same time and in the same place, based on fossil records. ## Footnote This suggests complex interactions among different hominid species.
71
What is the 'Out of Africa' model?
The hypothesis that Homo sapiens originated in Africa and displaced other hominids in Europe and Asia. ## Footnote This model has significant implications for understanding human migration.
72
What are the three hypotheses regarding the origin of Homo sapiens?
* Originated in Africa and displaced other hominids * Originated in Africa with some introgression with other lineages * All lineages originated in Africa with constant gene flow among them ## Footnote These hypotheses reflect different scenarios of human evolution and migration.
73
Describe the genetic similarity among humans.
Humans are genetically very similar due to constant gene flow. ## Footnote This genetic similarity is a result of historical interbreeding among populations.
74
What are geographic signatures in humans?
Subtle genetic differences that reflect geographic origins. ## Footnote Despite overall genetic similarity, these signatures indicate some degree of population structure.

BIOL 214 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions