H

Hoa

A channel or pass connecting an atoll lagoon with the open ocean, e.g. at Mururoa Atoll (French Polynesia)

 

Hybrid

An individual resulting from mating between genetically distinct populations/species. See also hybrid zone.

 

Hybrid Zone

A region in which genetically distinct populations come into contact and produce offspring off mixed ancestry. This process is known as hybridisation.

 

Hybridisation

See hybrid zone and hybrid. If new species are formed by hybridisation the hybrids must have higher fitness than the parental forms, they can achieve this by occupying new niches.

Hydrocarbon

A solid, liquid or gas composed of hydrogen and carbon. Examples include coal, oil and natural gas.