Genetics-And-Evolution-Evolution-3

Evolution:

• Process of gradual change in living organisms over time.

• Driven by natural selection, genetic variation, and other mechanisms.

• Evidence includes the fossil record, homologous structures, vestigial organs, molecular biology, and biogeography.

Speciation:

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

• Two types: allopatric (geographic isolation) and sympatric (within the same area).

• Involves isolation barriers, genetic drift, and natural selection.

• Crucial for biodiversity and understanding species formation.

Reproductive Isolation:

• Mechanisms preventing interbreeding between different species.

• Includes prezygotic (before fertilization) and postzygotic (after fertilization) barriers.

• Maintains genetic distinctiveness of species.

Hardy-Weinberg Equilibrium:

• A mathematical model to study population genetics.

• Conditions for equilibrium: no mutations, gene flow, large population, random mating, and no natural selection.

• Helps analyze genetic variation within populations.

Factors in Evolution:

• Mutation: Source of genetic variation.

• Natural Selection: Advantageous traits spread.

• Genetic Drift: Random allele frequency changes in small populations.

• Gene Flow: Gene movement between populations.

• Adaptation: Development of traits enhancing fitness.

• Extinction: Species disappearance due to environmental changes or competition.