Microevolution

1
Microevolution

• What is Microevolution?
• Natural Selection
• Genetic Drift
• Genetic Flow
• Adaptations to the Environment

2
Population

• Group of individuals of the same species in a
  given area
• Only populations evolve
• Polymorphism
• Different shapes, colors, ect
• Persistence of multiple traits can be qualitative
  or quantitative

3
Population

• Offspring inherit genes not phenotypes
• How do gametes get randomly produced?
• Mutation
• Crossing over
• Independent assortment
• Fertilization
• Change in chromosome number

4
Allele frequency

• Abundance of an allele in a population
• Genetic equilibrium
• Stable over time
• Microevolution
• Small changes in allele frequencies over time
• Mutations
• Heritable change in DNA
• Lethal mutations
• Neutral mutations

5
Hardy-Weinberg equilibrium

• No change in gene frequencies over time if
  certain conditions are met
• Random mating
• Large population
• No gene flow
• No mutations
• No natural selection

6
Types of Selection

• Stabilizing
• Intermediate forms are favored
• Gall size
• Disruptive
• Both extremes are favored
• Large or small bills
• Directional
• One extreme is favored

7
Microevolution Terms

• Sexual selection
• Certain traits favored by mates
• Heterosis
• Heterozygote is favored
• Gene flow
• Flow of alleles between populations
• Emigration vs. immigration

8
Microevolution Terms

• Genetic drift
• Random change in allele frequencies over time
• Bottleneck effect
• Reduction in population size and genetic
  diversity
• Founder effect
• A few individuals leave and start a new
  population
• Inbreeding
• Non random mating among closely related
  individuals