Biology Evolution Vocabulary

Adaptations

genetic traits that help an organism to survive or reproduce in its environment

Gene pool

all of the alleles within a population

Directional selection

one extreme phenotype is more fit than all the other phenotypes

Stabilizing selection

intermediate phenotypes are more fit than extreme ones

Disruptive selection

both extreme phenotypes are more fit than those in the middle

Non-random mating

mates are chosen randoming; some individuals have a higher/lower chance of reproducing

Bottleneck effect

the population shrinks suddenly due to natural disasters or human activities

Migration

individuals move between populations

Speciation

when one species splits into two or more different species

Geographic isolation

physical separation of members of the same species

Reproductive isolation

various mechanisms that prevent species from producing fertile offspring

Taxonomy

a system of grouping organisms according to their physical characteristics and traits

Cladistics

grouping of organisms based on evolutionary descent

Common ancestor

a species in the past from which new species have evolved

Cladograms

models that represent how organisms likely evolved from a common ancestor

Convergent evolution

when similar structures evolve in distantly related species due to similar selection pressures