Natural Selection

Question 1

Genetic diversity?

Answer 1

• number of alleles of genes in a population
• enables natural selection

Question 2

Natural selection?

Answer 2

• leads to evolution in population
• results in better adaptations - anatomical, physiological or behavioural

Question 3

Evolution?

Answer 3

• change in allele frequency over many generations in a population

Question 4

Stages of natural selection?

Answer 4

1. New alleles for gene created by random mutations
2. If new alleles are advantageous for survival in that environment - more likely to survive and reproduce
3. Reproduction passes on advantageous allele to next generation
4. Over many generations, new allele increases in frequency in the population

Question 5

Types of selection and aspects?

Answer 5

• Directional selection - extremes has the selective advantage, occurs when there’s a change in environment, modal trait changes
• Stabilising selection - modal trait has selective advantage, occurs when there’s no change in environment, modal trait stays the same, standard deviation decreases