Levels of selection

Individual/Organismal Level

photo-typical cases, where selections acts on populations through individuals

Cellular Level

cells within an individual may compete

Lamarckism

use and disuse

Gene level

gene-centric view of evolution

Richard Dawkins

wrote The Selfish Gene (1976). Individuals (or “bodies”) are vehicles for genes to propagate. argues that genes are the unit of selection

Evolutionary stable strategies

a behavioral or physical trait that, once adopted by a population, cannot be invaded or replaced by any rare, alternative mutant strategy through natural selection

memes

cultural unit of inheritance

Gould

argued that selection acts strictly on the phenotype, not the genes. Therefore, bodies (individuals) are the primary unit

Species/Group Level

selection occurs at the level or group, species, and/or clade

Circle of life

the natural force of life that moves ecosystems

natural theology

attempts to infer God's existence and attributes from the observation of the natural world and human reason rather than divine revelation

census

the singing of birds, clicking of insects, and the flickering of fireflies allows organisms to assess population size

kin-selection

since discreet groups (populations) are often close families of individuals, altruistic behavior may evolve as a means to propagate genes (gene level)

disadvantages to sex

• hard to find a mate

• 2-fold cost of sexual reproduction

advantages of sex

• increases variation among offspring

• speeds rate of evolution by allowed independent beneficial alleles to combine

• allows removal of deleterious alleles from population (recombination)

NOTE: disadvantages are to individuals, advantages are to populations/groups