Speciation

Speciation

The process by which new species are generated from pre-existing species.

Divergence

Differences accumulating in isolated populations over time due to lack of gene flow.

Reproductive Isolation Mechanisms

Factors that prevent interbreeding between populations.

Pre-Zygotic Mechanisms

Barriers that occur before fertilization that prevent mating or fertilization.

Temporal Barrier

A pre-zygotic mechanism that prevents mating due to differences in timing of reproduction.

Behavioral Barrier

A pre-zygotic mechanism involving unique mating rituals that prevent interbreeding.

Mechanical Barrier

A pre-zygotic mechanism regarding differences in reproductive structures.

Gametic Barrier

A pre-zygotic mechanism that prevents the fusion of gametes.

Hybrid Inviability

A post-zygotic mechanism where the embryo cannot develop to full independence.

Hybrid Sterility

A post-zygotic mechanism where hybrid offspring are not capable of reproduction.

Allopatric Speciation

Speciation that occurs due to geographic barriers preventing gene flow.

Sympatric Speciation

Speciation that occurs without geographic barriers, often due to preferences or mutations.

Polyploidy

An organism possessing multiple sets of chromosomes, often resulting from errors in cell division.

Gene Flow

The transfer of genetic information between populations, which can prevent speciation.

Example of Sympatric Speciation

The apple maggot fly, which has limited gene flow due to habitat preference.

Zygote

The single-celled diploid entity formed when sperm and egg fuse.

Divergence of Traits

The accumulation of differences in traits over time that lead to speciation.