Natural/sexual/kin selection, neutral theory, modern and extended evolutionary synthesis.
Evolution Mechanisms
Sexual selection
Darwin 1871: selection arising from mate competition (intrasexual) or mate choice (intersexual). Drives exaggerated traits (peacock tail,…
Kin selection / Hamilton's rule
Hamilton 1964: altruistic allele spreads when rb > c (r: genetic relatedness, b: recipient benefit, c: actor cost). Explains eusociality,…
Modern synthesis
1920s-1940s unification of Darwinian selection with Mendelian genetics (Fisher, Haldane, Wright, Dobzhansky, Mayr, Simpson, Stebbins).…
Extended evolutionary synthesis
Post-2000 proposal (Laland, Pigliucci, Odling-Smee) to expand the Modern Synthesis with niche construction, developmental plasticity,…
Punctuated equilibrium
Eldredge-Gould 1972: species spend most of their existence in stasis, with rapid morphological change concentrated at speciation events.…
Convergent evolution
Independent evolution of similar traits in unrelated lineages under similar selective pressures. Examples: camera eye (vertebrate,…
Exaptation
Gould-Vrba 1982: trait that currently serves a function different from the one for which it was selected. Examples: feathers…
Red Queen hypothesis
Van Valen 1973: species must continuously evolve just to maintain fitness against co-evolving antagonists (parasites, predators). Explains…
Genetic hitchhiking
Neutral or mildly deleterious alleles linked to a selected locus increase in frequency. Background selection + selective sweeps reduce…
Genetic load
Average fitness reduction relative to optimal genotype. Haldane-Muller mutation load, segregation load, substitution load. Sets limits on…