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The Biological Klepton Concept (BKC)

Article published in volume 8 fascicle 3, of 10/1990, pages 75 - 89



The proposal of Dubois & G√ľnther (1982) to create a new systematic category (klepton) embracing the hybridogenetic and gynogenetic taxa (sensu lineages, genealogies) is analyzed. Such taxa can be considered neither as simple hybrids nor as good species. Biological trends for all known kleptons in the Ambystoma, Rana, Phoxinus, Poecilia and Poeciliopsis complexes are summarized, and their new associated terms discussed. Kleptons are historical entities, but not of the classical Biological Species Concept (BCS sensu Mayr, 1982), but showing equally ecological, genetical, and evolutionary relevances as their associated good species. From an epistemological point of view, the fact that so-called kleptons are not subject to cladistic laws (because kleptons are polyphyletic), must not be considered as and argument for ignoring the existence of those taxa, either biologically or taxonomically. Klepton evolutionary rules, as parallel species pathways, are discussed: we conclude that not all evolutionary processes take place in the species context. The Biological Klepton Concept (BKC) is proposed: a klepton is a community of populations with a hybrid genome derived from the same parental species, reproductively dependent upon sympatric species that play the role of sexual host.