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Evolutionary Biology > Module 2 (Evolution of Populations) > Flashcards

Module 2 (Evolution of Populations) Flashcards

1
Q

__________ is a change in ALLELE FREQUENCIES in a population over generations

A

Microevolution

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2
Q

T or F;

Organisms evolve during their lifetimes.

A

False

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3
Q

What do you call the change of genetic composition of a population over time?

A

Evolution

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4
Q

What two things would natural selection lead to?

A

1.Population changing over generations.

  1. Evolutionary Adaptation.
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5
Q

What is the only mechanism that consistently causes adaptive evolution?

A

Natural selection

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6
Q

T or F;

Natural selection, genetic drift, and gene flow can alter allele frequencies in a population

A

True

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7
Q

What is the use of the Hardy-Weinberg equation?

A

It is used to test whether a population is evolving or not

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8
Q

T or F;

Genetic variation makes evolution possible

A

True

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9
Q

Sources for Genetic Variation;

A

Mutation

Rapid Reproduction

Altering of gene number or position

Sexual Reproduction and Recombination

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10
Q

Modified T or F;

Sensual Reproduction and Allele frequency produce the variation in gene pools that contribute to differences among individuals

A

False;
Sexual Reproduction and Recombination

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11
Q

Give two types of variable traits in a population.

A
  1. Polygenic traits
  2. Single gene traits
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12
Q

This trait results from the combined effects of several genes or determined by a single gene. Also, tend to produce phenotypes that vary more or less continuously.

A

Polygenic Traits

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13
Q

This type of variable trait tends to produce only a few distinct phenotypes.

A

Single Gene Trait

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14
Q

Modified T or F;

Variation in individual PHENOTYPE leads to variation in individual GENOTYPE

A

False;
Genotype leads to Phenotype variation

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15
Q

T or F;

Not all phenotypic variation is heritable

A

True

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16
Q

T or F;

Natural selection can only act on variation with a PHENOTYPIC component

A

False; genetic

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17
Q

Describe discrete Characters.

A

determined by a single gene that produces a distinct phenotype

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18
Q

Describe Quantitative Characters

A

Typically have a wide range and variation of phenotypes and are controlled by multiple genes

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19
Q

It is a group of organisms, all of the same species, which interbreed and live in the same place and time.

A

Population

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20
Q

T or F;

A population shares a common gene pool.

A

True

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21
Q

How do population geneticists measure polymorphisms in a population?

A

By determining the amount of heterozygosity at the gene and molecular levels.

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22
Q

What does average heterozygosity measure?

A

Average percent of loci that are heterozygous in a population.

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23
Q

How is Nucleotide variability measured?

A

It is measured by comparing DNA sequences of pairs between individuals.

24
Q

In terms of variation between populations, most species exhibit what type of variation?

A

Geographic Variation

25
Q

Modified T or F;

Genetic variation exists (or happens) within INDIVIDUALS.

A

False; populations

26
Q

What do you call a graded change in a trait along a geographic axis?

27
Q

This word describe changes in the NUCLEOTIDE SEQUENCES of DNA.

28
Q

T or F: Explain why if False.

Mutations in ALL TYPES of cells can be passed to offspring

A

False;

Only cells that produce gametes can pass mutations to offsprings.

29
Q

Define point mutation.

A

A change of ONE BASE in a gene. It can either be harmful or helpful in increasing fitness between organism and environment.

30
Q

Modified T or F;

Chromosomal mutations that delete, disrupt, or rearrange SINGLE loci are typically BENEFICIAL.

A

False:

Many (or multiple); Harmful

31
Q

T or False; Explain if False

Mutation rates are LOW in animals and plants. Mutations rates are often LOWER in prokaryotes and higher in viruses

32
Q

This is a word that describes all the alleles for all loci in a population.

33
Q

Modified T or F;

Locus is FLEXIBLE if all individuals in a population are homozygous for the same allele

A

False; fixed

34
Q

Modified T or F;

Allele frequencies in a population will remain CONSTANT unless one or more factors cause those frequencies to CHANGE.

35
Q

What are the five conditions for Hardy-Weinberg equilibrium?

A
  1. No Mutation (No genetic change)
  2. No Gene Flow (no migration of species)
  3. No Sexual selection
  4. No Genetic Drift (large population size)
  5. No Selection (Equal fitness)
36
Q

This type of genetic drift occurs when a few individuals become isolated from a larger population

A

Founder Effect

37
Q

This type of genetic drift is a sudden reduction in population size due to a change in the environment.

A

Bottleneck Effect

38
Q

Modified True or False;

Allele frequencies in the small founder population can be COMPLETELY SIMILAR from those in the larger parent population

A

False;

different

39
Q

Modified True or False;

The resulting gene pool may NO LONGER BE REFLECTIVE of the original population’s gene pool

40
Q

This factor of evolution is a change in the allele frequency due to transfer of alleles into or out of the gene pool

41
Q

This factor of evolution is the only mechanism that consistently causes adaptive evolution

A

Natural Selection

42
Q

Modified T or F;

Natural Selection brings about adaptive evolution by acting on an organism’s GENOTYPE.

A

False; Phenotype

43
Q

This word refers to the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals

A

Relative Fitness

44
Q

What are the three modes of Natural Selection? Explain each in your own words.

A
  1. Directional Selection (favors individuals at one end of the phenotypic range)

2.Disruptive selection (favors individuals at both extremes of the phenotypic range)

3.Stabilizing selection (favors intermediate individuals of the phenotypic range)

45
Q

What is the Key Role of Natural Selection in Adaptive Evolution?

A

Natural selection INCREASES the frequencies of alleles that enhance survival and reproduction

46
Q

This concept of evolution occurs as the match between an organism and its environment increases

A

Adaptive evolution

47
Q

This factor of Evolution refers to natural selection in terms of MATING success.

A

Sexual Selection

48
Q

This word refers to MARKED DIFFERENCES between the sexes in their secondary sexual characteristics.

A

Sexual Dimorphism

49
Q

A type of Sexual selection where competition among individuals of ONE SEX (often males) for mates of the opposite sex

A

Intrasexual selection

50
Q

A type of Sexual selection, often called mate choice, occurs when individuals of one sex (usually females) are choosy in selecting their mates

A

Intersexual selection

51
Q

Modified True or False;

Male showiness due to mate choice can DECREASE a male’s chances of attracting a female, while INCREASING his chances of survival

A

False; Increase then decrease

52
Q

What is this mechanism that maintains genetic variation in the form of hidden recessive alleles

53
Q

This is a concept that occurs when heterozygotes have a higher fitness than do both homozygotes

A

Heterozygote Advantage

54
Q

This concept of selection can favor whichever phenotype is less common in a population. The fitness of a phenotype declines if it becomes too common in the population

A

Frequency-Dependent Selection

55
Q

It is a type of genetic variation that appears to confer no selective advantage or disadvantage.

A

Neutral variation

56
Q

Why can’t natural selection fashion perfect organisms?

A
  1. Selection can act only on existing variations, favors the fittest
  2. Evolution is limited by historical constraints [does not “occur” out of the blue]
  3. Adaptations are often compromised
  4. The interaction of Chance, natural selection, and the environment.
56
Q

Why can’t natural selection fashion perfect organisms?

A
  1. Selection can act only on existing variations, favors the fittest
  2. Evolution is limited by historical constraints [does not “occur” out of the blue]
  3. Adaptations are often compromised
  4. The interaction of Chance, natural selection, and the environment.

Evolutionary Biology (5 decks)

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