Evolution

Question 1

What is evolution?

Answer 1

The change that happens over generations in the proportion of the individuals in a population which differ in one (or more) inherited traits.

Question 2

What are the ways that evolution can occur?

Answer 2

Genetic drift (random) , sexual selection and natural selection (non-random)

Question 3

What is genetic drift?

Answer 3

The random increase or decrease in frequency of inherited traits over a number of generations.

Question 4

Why does genetic drift have a greater effect in small populations?

Answer 4

Alleles are more likely to be lost from the gene pool of a small population.

Question 5

When is genetic drift noticed?

Answer 5

There is no selection pressures on the alleles, so this form of evolution is particularly seen when the allele has a neutral effect on evolutionary fitness.

Question 6

What is natural selection?

Answer 6

The non-random process which affects the allele frequency in the population over generations. It does this by selecting individuals based on their survival chances, and thus increases chances on their inheritance traits.

Question 7

What is sexual selection?

Answer 7

The non-random increase in the frequency of alleles that make mating and reproduction sound more likely. These do not necessarily increase survival chances.

Question 8

What is absolute fitness?

Answer 8

The ratio of frequencies of a particular genotype in one generation compared to the previous generation

Question 9

What is relative fitness?

Answer 9

The ratio of surviving offspring of one genotype compared with other genotypes

Question 10

Factors which increase the rate of evolution?

Answer 10

Higher selection pressures, shorter generation times, warmer environments, sexual reproduction, and horizontal gene transfer