KA 2 Flashcards

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

What is evolution?

A

It is the change over time in the proportion of individuals in a population differing in one or more inherited traits

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

During evolution, changes in allele frequency occur through what 3 processes?

A

The non-random processes of natural selection and sexual selection, and the random process of genetic drift

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

Natural selection acts on?

A

Genetic variation in populations Variation in traits arises as a result of mutation.

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

Mutation is the original source of new?

A

Alleles

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

New sequences can be what kind of alleles?

A

Novel alleles.

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

Most mutations are? But in some cases they may be?

A

Harmful or neutral, but in rare cases they may be beneficial to the fitness of an individual.

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

Populations produce …. Offspring than the environment can support

A

More

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

Individuals with variations that are better suited to their environment tend to?

A

Survive longer and produce more offspring, breeding to pass on those alleles that conferred an advantage to the next generation.

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

Selection results in the?

A

Non-random increase in the frequency of advantageous alleles and the non-random decrease in the frequency of deleterious alleles.

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

Sexual selection is the?

A

Non-random process involving the selection of alleles that increase the individual’s chances of mating and producing offspring

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

Sexual selection may lead to?

A

Sexual dimorphism

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

Sexual selection can be due to?

A

Male-male rivalry and female choice

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

What is male-male rivalry?

A

Where large size or weaponry increases access to females through conflict.

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

Female choice involves?

A

Females assessing the fitness of males.

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

Genetic drift occurs when?

A

Chance events cause unpredictable fluctuations in allele frequencies from one generation to the next

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

Genetic drift is more important for what kind of population?

A

Small populations, as alleles are more likely to be lost from the gene pool

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

Population bottlenecks occur when a?

A

Population size is reduced for at least one generation.

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

Population size is reduced for at least one generation.

A

Population size is reduced for at least one generation.

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

Founder effects occur through the?

A

Isolation of a few members of a population from a larger population.

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

The gene pool of the new population is not …… of that in the original gene pool.

A

Representative

21
Q

A gene pool is altered by? Why is this?

A

Genetic drift because certain alleles may be underrepresented or over-represented and allele frequencies change

22
Q

Where selection pressures are strong, what can be rapid?

A

The rate of evolution

23
Q

Selection pressures are the?

A

Environmental factors that influence which individuals in a population pass on their alleles.

24
Q

What are some biotic factors?

A

Competition, predation, disease, parasitism; or abiotic: changes in temperature, light, humidity, pH, salinity.

25
Q

The Hardy-Weinberg (HW) principle states that?

A

In the absence of evolutionary influences, allele and genotype frequencies in a population will remain constant over the generations

26
Q

The conditions for maintaining the HW equilibrium are?

A

No natural selection, random mating, no mutation, large population size and no gene flow (through migration, in or out).

27
Q

The HW principle can be used to determine?

A

Whether a change in allele frequency is occurring in a population over time

28
Q

Changes suggest what is occurring?

A

Evolution

29
Q

Use the HW principle to calculate?

A

Allele, genotype and phenotype frequencies in populations.

30
Q

What is the HW principle equation and what do the letters represent?

A

P2+ 2pq + q2 =1
p = frequency of dominant allele
q = frequency of recessive allele
p2 = frequency of homozygous dominant genotype
2pq = frequency of heterozygous genotype
q2 = frequency of homozygous recessive genotype

31
Q

Fitness is an indication of?

A

An individual’s ability to be successful at surviving and reproducing

32
Q

Fitness is a measure of the?

A

Tendency of some organisms to produce more surviving offspring than competing members of the same species.

33
Q

Fitness refers to the?

A

Contribution made to the gene pool of the next generation by individual genotypes

34
Q

Fitness can be defined in what 2 terms?

A

Absolute or relative terms

35
Q

Absolute fitness is the?

A

Ratio between the frequency of individuals of a particular genotype after selection, to those before selection frequency of a particular genotype after selection frequency of a particular genotype before selection.

36
Q

If the absolute fitness is 1, then what is stable?

A

The frequency of that genotype

37
Q

A value greater than 1 conveys an increase in the?

A

Genotype and a value less than 1 conveys a decrease.

38
Q

Relative fitness is the ratio of the?

A

Number of surviving offspring per individual of a particular genotype to the number of surviving offspring per individual of the most successful genotype number of surviving offspring per individual of a particular genotype number of surviving offspring per individual of the most successful genotype

39
Q

Co-evolution is the process by which?

A

Two or more species evolve in response to selection pressures imposed by each other

40
Q

A change in the traits of one species acts as a?

A

Selection pressure on the other species

41
Q

Co-evolution is frequently seen in?

A

Pairs of species that have symbiotic interactions

42
Q

What is symbiosis?

A

Co-evolved intimate relationships between members of two different species.

43
Q

The impacts of these relationships can be? For whom?

A

Positive (+), negative (-) or neutral (0) for the individuals involved

44
Q

Mutualism, commensalism, and parasitism are types of?

A

Symbiotic interactions

45
Q

What is mutualism?

A

Where both organisms in the interaction are interdependent on each other for resources or other services. As both organisms gain from the relationship, the interaction is (+/+).

46
Q

What is commensalism?

A

Only one of the organisms benefits (+/0).

47
Q

What is parasitism?

A

Where the parasite benefits in terms of energy or nutrients and the host is harmed as the result of the loss of these resources

48
Q

The Red Queen hypothesis states that?

A

In a co-evolutionary relationship, change in the traits of one species can act as a selection pressure on the other species this means that species in these relationships must adapt to avoid extinction