Evolution of Populations-(Fall 2024) (1)

Population Genetics:

• Study of genetic variations within populations and how these variations change over time.

• Key focus on alleles, genotypes, and phenotypes.

Hardy-Weinberg Principle:

• A model that describes how allele frequencies remain constant from generation to generation in an ideal population that is not evolving.

• Conditions for a population to be in Hardy-Weinberg equilibrium include:

  • No mutation

  • Random mating

  • No natural selection

  • Extremely large population size

  • No gene flow.

Natural Selection:

• The process by which individuals with favorable traits are more likely to survive and reproduce.

• Leads to adaptation, where populations evolve to become better suited to their environments.

Genetic Drift:

• A random process that can cause allele frequencies to change over time, especially in small populations.

• Examples include the bottleneck effect and founder effect.

Gene Flow:

• The transfer of alleles or genes from one population to another, which can introduce new genetic material into a population.

• Can counteract the effects of natural selection and genetic drift.

Mutation:

• The ultimate source of genetic variation in populations, providing new alleles.

• Mutations can be beneficial, harmful, or neutral, influencing evolutionary processes.

Speciation:

• The process by which new species arise from existing ones.

• Often occurs due to reproductive isolation, where different populations evolve independently due to barriers such as geography or behavior.

Adaptation:

• Changes in traits that enhance an organism's ability to survive and reproduce in its environment.

• Can occur through processes like natural selection and also involves behavioral and physiological changes.

Evolutionary Fitness:

• The relative measure of an organism's reproductive success in passing its genes to the next generation.

• Often tied to the concept of adaptation and survival in