Week 2

Question 1

Changes in allele frequencies

Answer 1

A shift in how common different alleles are in a population over generations

Question 2

Non-random mating

Answer 2

When individuals choose mates based on specific traits rather than randomly

Question 3

Genetic Drift

Answer 3

Random changes in allele frequencies due to chance events

Question 4

Founder Effect

Answer 4

• Type of genetic drift
• when a small group starts a new population with limited genetic diversity

Question 5

When is the founder effect the most common?

Answer 5

• When its undergoing a major shift in its distribution
• When humans move species
• During range shifting due to climate change

Question 6

Population Bottlenecks

Answer 6

• A sharp reduction in population size, leading to lost genetic diversity
• Population might regrow

Question 7

What is between-generation sampling error?

Answer 7

Errors that occur between generations when populations are constant in size

Question 8

Gene flow

Answer 8

The movement of alleles between populations through migration or breeding

Question 9

What is the relationship between genetic variation and population size?

Answer 9

Larger populations tend to have more genetic variation

Question 10

Directional Selection

Answer 10

Natural selection that favours one extreme phenotype, shifting traits in a population

Question 11

Stabilizing Selection

Answer 11

Selection that favours average traits and reduces extremes

Question 12

Disruptive Selection

Answer 12

Selection that favours extreme traits over the average

Question 13

Heterozygote advantage

Answer 13

Heterozygotes have higher fitness than homozygotes, often due to disease resistance

Question 14

Underdominance

Answer 14

• Opposite of heterozygote advantage
• heterozygotes have lower fitness than either homozygote, leading to the disadvantage of mixed alleles

Question 15

Sexual Selection

Answer 15

When traits that increase an individual’s chances of attracting a mate are favoured

Question 16

Sexual Dimorphism

Answer 16

Differences in appearance between males and females of the same species

Question 17

What is the good gene hypothesis?

Answer 17

The idea that females prefer mates with traits signaling good health or strong genes for better offspring

Question 18

What phenomenons posed problems for evolution and genetics?

Answer 18

1. Quantitative traits
2. Dominance

Question 19

What is the equilibrium principle?

Answer 19

Allele frequencies in a population remain constant over time unless influenced by evolutionary forces

Question 20

4 forces of non-equilibrium

Answer 20

1. Genetic Drift
2. Nonrandom Mating
3. Gene Flow
4. Fitness Differences

Question 21

Nonrandom Mating

Answer 21

Mating where individuals select partners based on specific traits, rather than randomly

Question 22

Fitness Differences

Answer 22

Variations in survival and reproductive success among individuals due to different traits

Question 23

The modern synthesis

Answer 23

The integration of Darwin’s theory of evolution with genetics, explaining evolution as changes in allele frequencies over time

Question 24

Neo-Darwinism

Answer 24

A modern theory combining Darwin’s natural selection with Mendelian genetics, explaining evolution through genetic variation and survival of the fittest

Question 25

Quantitative Genetics

Answer 25

It's the study of traits that vary a lot and are controlled by many genes

Question 26

Heritability

Answer 26

The proportion of variation in a trait that is due to genetic factors, as opposed to environmental factors in a population

Question 27

Plasmodium parasites

Answer 27

- Causes malaria - complex life cycle involving two hosts

Question 28

How is malaria related to natural selection?

Answer 28

Malaria drives natural selection by favoring genetic traits like sickle cell allele, which provides resistance to the disease in heterozygotes

Question 29

Sickle-Cell Anaemia

Answer 29

A genetic disorder causing misshapen red blood cells