For centuries, biological species have been identified on the basis of morphological traits. More recently, a reproductive concept has become the relevant criterion for species definition: only individuals that were able to successfully mate and produce viable offspring were considered as belonging to the same species. However, the most recent advances of scientific technologies have paved the way for new, more nuanced interpretations. Genetic techniques can shed light on some “natural anomalies” that seem to challenge the biological species concept.

One of these evolutionary puzzles is the Caucasian rock lizard (Darevskia portschinskii), inhabiting Georgia, northern Armenia and northwestern Azerbaijan. The species is able to successfully interbreed with the sympatric Darevskia mixta, generating the parthenogenetic hybrid Darevskia dahli. In addition, D. portschinskii is divided into two subspecies, identified exclusively on morphological and geographical bases.

A recent contribution, published on Issue 18(2) of Acta Herpetologica, explores the genetic basis of the division of D. portschinskii populations into two different subspecies. The authors developed ten microsatellite markers to analyze genetic material collected from 43 Caucasian rock lizards coming from three different populations.  

The results of the study showed that the 10 developed microsatellites confirm the distinction of D. portschinskii into two different subspecies, as suggested by morphological characters. Notably, the genetic analyses correctly classify two geographically distant populations as members of D. portschinskii  portschinskii. At the same time, the microsatellites exhibit remarkable efficiency in discerning between two geographically proximate populations, identifying them as belonging to separate subspecies. This suggests a promising avenue for refining the classification of Darevskia species and subspecies. The results, indeed, advocate for the superior reliability of microsatellites over existing genetic techniques in the comprehensive study of Darevskia taxonomy.

The full paper is available here.

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