Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIO1M03 > Evolution - Ch 23 - Evolutionary Processes > Flashcards

Evolution - Ch 23 - Evolutionary Processes Flashcards

1
Q

How do we know whether evolution or biased mating is occurring?

A

Hardy-Weinberg Principle

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

What are the 4 modes of natural selection?

A

directional selection, balancing selection, stabilizing selection, disruptive selection

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

Which sex is more affected by sexual selection, and why?

A

sexual selection acts more strongly on males than females since any allele that increases a male’s attractiveness or success in intrasexual competition should quickly pop up in a population

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

What is the Hardy-Weinberg equilibrium equation (for two traits, p and q)

A

p^2 + 2pq + q^2 = 1

[p + q = 1]

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

What is purifying selection, and what mode of selection does it fall under?

A

disadvantageous alleles tend to decrease in frequency, and fall to 0 frequency (while favoured alleles become fixed)

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

What is a gene pool?

A

all the alleles of all the genes of a certain population

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

What is genetic variation?

A

the number and relative frequency of alleles present in a population

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

What does stabilizing selection do? How does it affect genetic variation?

A

selects against both extremes

-decrease in genetic variation

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

What does disruptive selection do? How does it affect genetic variation?
What can it lead to?

A

(opposite of stabilizing) the middle is selected against

  • increases genetic diversity
  • can lead to speciation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does balancing selection do? How does it affect genetic variation?

A

no alleles have a distinguishable advantage, at all times

-genetic variation stays the same

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

What can cause balancing selection?

A
  • heterozygote advantage

- frequency-dependent selection

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

What is frequency-dependent selection?

A

when specific alleles are favoured when rare, but disadvantageous when common

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

What is genetic drift? What populations are most affected by it?

A

the change in allele frequency in a population, by chance

-is significant in smaller populations

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

What is genetic drift? What populations are most affected by it?

A

the change in allele frequency in a population, by chance

-is more significant in smaller populations

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

What is genetic drift? What populations are most affected by it?

A

the change in allele frequency in a population, by chance
-is more significant in smaller populations
-

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

What is genetic drift? What populations are most affected by it?

A

the change in allele frequency in a population, by chance

-is more significant in smaller populations (more prone to fixation/loss of alleles)

17
Q

How is the genetic variation of a population affected by natural selection, genetic drift, genetic flow, and mutations?

A
  • natural selection: depends on mode
  • genetic drift: neutral
  • genetic flow: increase or decrease
  • mutations: increase
18
Q

How is the genetic variation of a population affected by natural selection, genetic drift, genetic flow, and mutations?

A
  • natural selection: depends on mode
  • genetic drift: neutral
  • genetic flow: increase or decrease
  • mutations: increase
19
Q

What is a founder event, and what is the founder effect?

A
  • founder event: when a group of individuals immigrate to a new geographical area to start a new population
  • founder effect: when a founder event occurs that causes a change in allele frequencies (compared to the original population) due to sampling error of small population
20
Q

What is a population bottleneck, and what is a genetic bottleneck?

A
  • population bottleneck: when a large population suddenly loses a high number of individuals
  • genetic bottleneck: when a great amount of alleles decrease in number, which by chance likely changes the allele frequency of the population and decreases genetic variation
21
Q

What is gene flow?

A

the movement of alleles between populations when an individual migrates between them

22
Q

What is the ultimate source of genetic variation?

A

mutations

23
Q

What is a chromosome-level mutation?

A

the change in number of composition of chromosomes, which can duplicate genes, leading to loss of function or new alleles

24
Q

What is a lateral gene transfer?

A

the movement of genes from one species to another

25
Q

How quickly does mutations cause evolution

A

very slowly, by itself it is not a significant factor of evolution

26
Q

What are some types of biased mating?

A

inbreeding and assortative mating

27
Q

Does inbreeding or assortative mating cause evolution?

A

NO because they only change genotype frequencies, not allele frequencies

28
Q

What is inbreeding depression?

A

the decrease in average fitness when homozygosity increases and heterozygosity decreases (caused by close relatives mating with each other)
-occurs because many recessive alleles represent loss of function mutations

29
Q

What is assortative mating? What is positive assortment, and what is negative assortment?

A

when mates are chosen based on certain traits

  • positive: when individuals tend to mate with those with a shared phenotypic trait as them
  • negative: when individuals tend to mate with those with a different specific phenotypic trait
30
Q

What is sexual selection? Can it cause evolution? What are the two types?

A

The favouring of individuals with traits that increase their ability to attract mates or choose good mates. Yes, it causes evolution.
-intersexual choice and intrasexual selection

31
Q

What is intersexual choice?

A

when an individual of one sex (females usually0 chooses a specific indivudual of the other sex for mating

32
Q

What is intrasexual selection?

A

selection driven by competition among members of one sex (males usually) for an opportunity to mate

33
Q

What is the pattern and process of the animal theory of The Fundamental Asymmetry of Sex?

A
  • pattern: traits that attract the opposite sex are much more gaudy/elaborate in males
  • process: eggs are more expensive energy-wise than sperm are
34
Q

What is sexual dimorphism?

A

any trait that differs between males and females

BIO1M03 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions