Sympatric speciation

Sympatric speciation is a process in evolution where new species evolve from a single ancestral species while inhabiting the same geographic region. In sympatric speciation, even though the new evolving populations are in close physical proximity, they become reproductively isolated and diverge genetically.

Mechanisms of Sympatric Speciation

Sympatric speciation can occur through several mechanisms, including polyploidy, sexual selection, and ecological speciation.

Polyploidy

Polyploidy is a condition where the number of chromosomes in an organism's cell doubles. This can occur due to errors in meiosis, the process of cell division that produces reproductive cells. Polyploidy can lead to sympatric speciation as the polyploid individuals are unable to breed with their diploid ancestors, leading to reproductive isolation.

Sexual Selection

Sexual selection is a mode of natural selection where members of one biological sex choose mates of the other sex to mate with, and compete with members of the same sex for access to members of the opposite sex. This can lead to sympatric speciation as different traits may be selected for in different populations, leading to reproductive isolation.

Ecological Speciation

Ecological speciation is the process by which ecologically based divergent selection between different environments leads to the creation of reproductive barriers between populations. This can occur in sympatric populations if different populations become adapted to different niches within the same geographic area.

Examples of Sympatric Speciation

Examples of sympatric speciation include the cichlid fishes in African lakes, where it is thought that differences in feeding habits have led to speciation. Another example is the Hawthorn fly, where it is thought that a shift in host plant from hawthorn to apple has led to speciation.

See Also

• Allopatric speciation
• Peripatric speciation
• Parapatric speciation