Evolution of biological diversity: diversification of thechorthippus biguttulus species group in Anatolia

Mechanisms of speciation and hence the definition of species belong to the most discussed and controversial issues in biology. In sexually reproducing organism, a species is a group of individuals that actually or potentially interbreeding and such units are isolated from other similar groups by pre- and/or postzygotic reproductive isolation mechanisms. Thus studying the evolutionary mechanisms underlying reproductive isolation of closely related species is one of the most active areas of evolutionary biology. Male and female of the C. biguttulus group find each other by acoustic signals like in many acoustically communicating animals. These signals are often speciesspecific and can play an important role in both sexual selection and prezygotic reproductive isolation. Members of C. biguttulus group communicate by acoustic signals and that is why they have widely been used in the research on the topics described above. All field studies were carried in appropriate locations of Anatolia to obtain data for phenotypic and genetics. During field studies, distribution area of C. biguttulus group was found from 1500 m sometimes over and, mostly in forest remnant and subalpine meadow. In all populations, first song of animals recorded for identification of species. Afterwards specimens used for morphological and molecular studies. Song analysis showed that three sub units (C. biguttulus, . brunneus and C. molis) in the C. biguttulus group have members in Anatolia and their leg movement pattern described in detail with this study. Morphometric measurements carried in as man as possible populations to compare whether there are any congruent between song and morphometric analysis. Results of the morphometrics analysis showed that it is possible to discriminant closely related units such as species or subspecies with morphology based data. Two new species were described depend on data sets in C. brunneus sub group, C. relicticus according to song characters and C. antecessor with distinctive morphology in all sub group.. When data about morphology and song of group members combined and compared with geographical distribution, we can suggest that plausible two scenarios which are C. antecessor is more like to ancestral form of the C. brunneus sub group and C. ilkazi for the C. biguttulus sub group. Results of the molecular analysis were not able to bring any solution to relations in-group, however there was only one interesting results about molecular analyse which is C. mollis mollis from Anatolia looks like the ancestral form of the all group. By evaluating morphological, song and genetic data, it is concluded that; (1) song data is the most important characters for identification off sub groups and species recognitions, beside morphology also could give useful results depend on appropriate analyses (2) group prefer the cold climatic conditions but not derivated from north, possibly from south refugias.such as Anatolia(3) up to now most literature about this group suggested that last glacial cycles is the important for the diversty of the group, however data from this study does not support this assumption but pushes the origin of the subgroups to a much earlier date in the Pleistocene period. In this case, the initial radiation within the C. biguttulus group should be in an earlier period. KEY WORDS: Chorthippus biguttulus group, Biodiversity, Evolution, Anatolia