Biodiversity is the variety of ecosystems, species, populations within
species, and genetic diversity within species. The biological diversity of
the planet is being rapidly depleted as a direct and indirect consequence
of human actions. An unknown but large number of species are already
extinct, while many others have reduced population sizes that put
them at risk (WCMC 1992). Many species now require benign human
intervention to improve their management and ensure their survival.
The scale of the problem is enormous, as described below. The current
extinction problem has been called the ‘sixth extinction’, as its magnitude
compares with that of the other five mass extinctions revealed in
the geological record (Leakey & Lewin 1995). Extinction is a natural part
of the evolutionary process. For example, the mass extinction at the end
of Cretaceous 65 million years ago eliminated much of the previous
flora and fauna, including the dinosaurs. However, this extinction
made way for proliferation of the mammals and flowering angiosperm
plants. The sixth extinction is different. Species are being lost at a rate
that far outruns the origin of new species.
Conservation genetics, like all components of conservation biology,
is motivated by the need to reduce current rates of extinction and to preserve
biodiversity.
Biodiversity is the variety of ecosystems, species, populations withinspecies, and genetic diversity within species. The biological diversity ofthe planet is being rapidly depleted as a direct and indirect consequenceof human actions. An unknown but large number of species are alreadyextinct, while many others have reduced population sizes that putthem at risk (WCMC 1992). Many species now require benign humanintervention to improve their management and ensure their survival.The scale of the problem is enormous, as described below. The currentextinction problem has been called the ‘sixth extinction’, as its magnitudecompares with that of the other five mass extinctions revealed inthe geological record (Leakey & Lewin 1995). Extinction is a natural partof the evolutionary process. For example, the mass extinction at the endof Cretaceous 65 million years ago eliminated much of the previousflora and fauna, including the dinosaurs. However, this extinctionmade way for proliferation of the mammals and flowering angiospermplants. The sixth extinction is different. Species are being lost at a ratethat far outruns the origin of new species.Conservation genetics, like all components of conservation biology,is motivated by the need to reduce current rates of extinction and to preservebiodiversity.
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