Key Concepts on Evolution and Natural Selection

Evolution and Natural Selection

• Involves changes in species over time driven by natural selection.
• Darwin's finches as an example of adaptation.

Key Historical Figures

• Anaximander: Early ideas of evolution; animals from the sea.
• Linnaeus: Developed naming system; believed species were fixed.
• Darwin: Influenced by Malthus on competition for resources, observed diverse species.

Darwin's Voyage

• Collected data on species variation during HMS Beagle voyage (1831-1836).
• Observed unique species on isolated islands.

Principles of Natural Selection

1. Struggle for existence: Competition for resources.
2. Variation and adaptation: Genetic differences enhance survival.
3. Survival of the fittest: Well-adapted individuals reproduce more.

Evidence of Evolution

• Biogeography shows distribution of species.
• Anatomical similarities, genetic data support evolutionary connections.

Population Genetics

• Population: Group of interbreeding individuals.
• Gene Pool: Total genetic diversity in a population.
• Allele Frequency: Proportion of a specific allele in a gene pool.
• Evolution involves changes in allele frequencies over time.

Sources of Genetic Variation

1. Mutations: Introduce new genetic material.
2. Genetic recombination during sexual reproduction.
3. Lateral gene transfer: Especially in bacteria.

Speciation Processes

• Allopatric: Due to geographical isolation.
• Sympatric: Occurs without physical separation.
• Mechanisms of isolation (behavioral, geographical, temporal, etc.).

Phylogenetic Relationships

• Phylogenies illustrate evolutionary relationships through trees.
• Constructed based on morphology, development, molecular data, etc.
• Example: Transmission of diseases like HIV through evolutionary analysis.