Swarm of species

from Wikipedia, the free encyclopedia

In evolutionary biology, a swarm of species is a group of very closely related species that evolved from an original species in an isolated area and now coexist in the same area. In the course of adaptive radiation , the less specialized species has adapted to the various existing environmental conditions and today occupies different ecological niches.

An example of a flock of species are the 14 species of Darwin's finches , which were described by Charles Darwin and which adapted to various ecological niches in the Galapagos Islands .

The Antarctic fish are a group of over 100 marine fish species that can live in the Southern Ocean because glycoproteins in their blood prevent freezing to death at temperatures around and below freezing point. Other swarms of species are the many species of cichlids in the great lakes of East Africa , the hamlet perches of the Caribbean and the hard corals of the Acropora genus in the coral reefs of the tropical Indo-Pacific .

The frequently used term species complex (also species complex or complex for short ) does not necessarily mean the same thing . Here, too, one understands in biology a group of species that can be addressed as a group due to similarities, be it a closer genetic relationship or a similar appearance. The individual members are not necessarily already nominally described. On the contrary, the species relationships are often still unclear. In contrast to the species swarm, the species complex can get by with fewer members (already two form a complex). To clarify: the entire cichlids of Lake Malawi or the large groups ( Mbuna and so-called "Malawi Haplochromis ") each form a swarm of species, the "blue-black zebras" from the Mbuna group form a species complex. The large barbs of Lake Tana in Ethiopia, on the other hand, are a species complex and a swarm of species in one. It is also not stipulated that the members of a species complex must coexist in the same area, as is the case with a swarm of species. A species complex can e.g. B. also sibling species (engl. Sibling species) consist, in an extreme case it contains cryptic species . The taxon of the most famous group member is usually used to give the group its name.

literature

  • Lexicon of Biology. Volume 2., Spektrum Akademischer Verlag, Heidelberg, 1999 ISBN 3-8274-0327-8