Biological Evolution and Genetics

Biological Evolution

• Biological evolution is the change in a population's inherited traits over many generations.
• A population is a group of the same species with different traits.
• Traits are coded by genes, therefore variation in traits results in variation in genes within that species' population.
• Changes in genes can affect the evolution of a population.

Gene Flow

• Gene flow is the movement of genes between populations.
• Gene flow can occur through migration.
• Migration can influence the genetic makeup of a population.

Mutation

• Mutation is a change in an organism's genetic material.
• Mutations can be harmful, beneficial, or neutral.
• Mutations can alter a population's genetic makeup.

Genetic Drift

• Genetic drift is a random change in the genetic makeup of a population.
• Genetic drift occurs because of random events.
• The remaining population, after a random event, may no longer reflect the original genetic makeup of the population.
• This change is due to a random event.

Natural Selection

• Natural selection is when a population that is well-adapted to its environment has a higher chance of survival.
• Organisms well-adapted to their environment are more likely to survive and reproduce.
• The organisms that survive and reproduce contribute to successful adaptations in the population.
• Organisms that have less suitable adaptations are less likely to reproduce and their genes are less likely to be passed to the next generation. Organisms that die have less or no reproductive opportunities. This leads to higher fitness (better adapted) in the population.

Evolutionary Evidence: Homology

• Homology is similarity due to a common ancestor.
• Molecular evidence supports the idea that certain animals are more closely related due to similar DNA.
• Anatomical structures that are similar in arrangement and pieces, but have different functions, may indicate common ancestry.
• Similar structures do not always mean the organisms are related. For example, bird wings and butterfly wings, despite having similar functions, are not directly related.

Test your understanding of biological evolution, including gene flow, mutation, and genetic drift. Explore how these concepts contribute to the changes in genetic makeup of populations over generations. This quiz will enhance your knowledge of evolutionary biology.