22_Speciation

Allopatric Speciation

A type of speciation that occurs when populations are geographically isolated, leading to genetic divergence.

Sympatric Speciation

Speciation that occurs without geographic isolation, often through mechanisms like polyploidy or habitat differentiation.

Polyploidy

A condition in which an organism has more than two complete sets of chromosomes, commonly observed in plants.

Autopolyploid

An individual that has more than two chromosome sets derived from a single species.

Allopolyploid

A hybrid organism that possesses two or more sets of chromosomes derived from different species.

Reproductive Barrier

Any mechanism that prevents two species from interbreeding and producing fertile offspring.

Hybrid Zone

A region where populations of different species meet and mate, producing hybrid offspring.

Reinforcement

The process by which natural selection increases reproductive barriers between diverging species.

Behavioral Prezygotic Barrier

A reproductive barrier that prevents mating due to differences in behavior, such as mating calls or coloration.

Punctuated Equilibria

An evolutionary model suggesting that species experience rapid changes followed by long periods of stability.

Gradualism

An evolutionary model that proposes species evolve slowly over time through small changes.

Speciation

The evolutionary process through which populations evolve to become distinct species.

Gene Flow

The transfer of genetic variation from one population to another.

Sexual Selection

A process where individuals with certain inherited traits are more likely than others to obtain mates.

Cichlids in Lake Victoria

An example of rapid speciation driven by sexual selection and ecological differentiation.

Natural Selection

The process where organisms better adapted to their environment tend to survive and produce more offspring.

Genetic Drift

A mechanism of evolution that involves random changes in the frequency of alleles in a population.