A process in which organisms with certain inherited traits are more likely to survive and reproduce than are organisms without those traits.

The evolution of similar features in independent evolutionary lineages.

A permanent, heritable change in the nucleotide sequence in a gene or a chromosome; the process in which such a change occurs in a gene or in a chromosome

A principle stating that both allele and genotype frequencies in a randomly-mating population remain constant - and remain in this equilibrium across generations -- unless a disturbing influence is introduced.

Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.

individual reproductive success and is equal to the average contribution to the gene pool of the next generation that is made by individuals of the specified genotype or phenotype.

The process of natural selection involving the genome for a species directionally choosing certain genes to remain prominent in the species, such as a growth in size in response to predation

This type of selection favors both the extremes at the expense of the average.

A form of natural selection in which, according to Darwin's theory, the male or female is attracted by certain characteristics, form, color, behavior, etc., in the opposite sex; thus modifications of a special nature are brought about in the species.

the case in which the heterozygote genotype has a higher relative fitness than either the homozygote dominant or homozygote recessive genotype.

The process in which new genetically distinct species evolve usually as a result of genetic isolation from the main population.

gene Flow is prevented between two populations of the same species. Reproductive isolating mechanisms are factors like different mating seasons or calls

A reproductive barrier that impedes mating between species or hinders fertilization of ova if interspecific mating is attempted.

A speciation in which biological populations are physically isolated by an extrinsic barrier and evolve intrinsic (genetic) reproductive isolation, such that if the barrier breaks down, individuals of the population can no longer interbreed.

A speciation in which new species evolve from a single ancestral species while inhabiting the same geographic region.

the diversification of a group of organisms into forms filling different ecological niches

A theory that describes an evolutionary change happening rapidly and in brief geological events in between the long periods of stasis (or equilibrium)

the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age, (i.e. estimated age)

In evolution, a theory is conceptualized wherein early cells (i.e. a prokaryotic cell) living within the host cell over time became the organelles (i.e. mitochondria and chloroplasts) within the eukaryotic cell.

a biological adaptation where the biological function currently performed by the adaptation was not the function performed while the adaptation evolved under earlier pressures of natural selection.