GB1 Ch. 22 - Evolution by Natural Selection

adaptation

heritable trait that increases the fitness of an individual in a particular environment relative to individuals lacking the trait

fitness

ability of an individual to produce surviving, fertile offspring relative to that ability in other individuals in the population

natural selection

when individuals with certain heritable traits produce more surviving offspring than do individuals without those traits

artificial selection

choose certain individuals with desirable traits to reproduce, thus manipulating the composition of the population

speciation

process that results in new species being formed from preexisting species

structural homology

similarity in adult morphology, or form.

developmental homology

similarity in developmental structures or processes

genetic homology

similarity that occurs in DNA nucleotide sequences, RNA nucleotide sequences, or amino acid sequences

homology

similarity that exists in species due to common ancestry

phylogenic tree

a branching diagram that depicts the ancestor–descendant relationships among species or other taxa

vestigial trait

reduced or incompletely developed structure that has no function, or reduced function, but is clearly similar to functioning organs or structures in ancestral or closely related species

transitional feature

trait in a fossil species that is intermediate between those of ancestral (older) and derived (younger) species

extinct species

species that no longer exist

extant species

species living today

acclimatation

change in an individual’s phenotype that occurs in response to a change in natural environmental conditions

alleles not changed, not passed onto offspring

fitness trade-off

compromise between two traits that cannot be optimized simultaneously.

genetic correlation

when selection on one trait causes a change in another trait