Evolution

Question 1

Definition of evolution

Answer 1

The changes in allele frequency across generations

Space and Time

Question 2

2 methods to study evolution

Answer 2

Mendelian
Quantitative (environment影响最大）

Question 3

5 key mechanisms of evolution

Answer 3

Mutation
Genetic drift
Natural Selection
Sexual Selection
Gene flow

Question 4

Mutation

Answer 4

Ultimate source of all genetic variation
Change genetic code, new allele alter gene expression, change phenotypes
Most decrease fitness
Few beneficial small effects

Question 5

Genetic drift

Answer 5

Random changes in allele frequency
The survivor clones

Question 6

Natural selection

Answer 6

Darwin and Wallace insight

All organisms have a potential for exponential growth
Traits varies among individuals
Traits influence survival
Traits are heritable

Prediction: traits that improve survival should increase in frequency through time

Question 7

Sexual selection

Answer 7

Intra sexual: male-male competition
Inter sexual: female choice

Example widow bird

Question 8

Secondary sexual trait

Answer 8

Evolve as the compromise between nature and sexual selection

Question 9

Gene flow

Answer 9

Movements of gene among populations
Result: often oppose effects of the divergent natural selection