Endemism


 

Paleoendemic species

These species are often systematically isolated taxa, whose distribution areas represent the remnants of originally larger distribution ranges that have been reduced due to environmental changes. Check-out this phenomenon on the figure! The Ice Age, for example, led to the extinction of many species in the European Alps. However, several species could survive in non-glaciered areas at the south-western and the south-eastern end of the Alpine chain. Today, these two regions represent centres of paleoendemic species. Berardia subacaulis, for example, is one of them; it grows today as a relict of the Tertiary period in a part of the French Alps.
 

Neoendemic species

These species result from the divergent adaptation to differing environmental conditions thereby leading to the formation of new species that are locally distributed. The evolution of neoendemic plant species is often triggered by polyploidy. The endemic species may have a higher ploidy level than its related taxa (apoendemics), or it may be diploid while its related taxa have a higher ploidy level (patroendemics). In cases where the endemic taxon and its related taxa are of equal ploidy level, the endemic species are called schizoendemics. Apo-, patro-, and schizoendemics are further subdivisions of neoendemics. Achillea erba-rotta s.str. and Achillea erba-rotta ssp. moschata are typical examples for neoendemics.
 

 To explore the development of these two types of endemic species, click on the figures below.

 


Tuesday, 28 October 2003, 11:00
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