Phylogeography of a Darevskia (caucasica) complex (Lacertidae: Sauria) based on the cytochrome b mitochondrial gene analysis

Abstract

The range of superspecific complex of rock lizards Darevskia (caucasica) (D. alpina, D. c. caucasica, D. c. vedenica, D. daghestanica) includes the Main Caucasian ridge and its spurs on the southern and northern macroslopes within heights from 500 m to 3200 m above sea level. A fragment of the mitochondrial cytochrome b gene (1096 bp) was analyzed in 48 specimens of these lizards. Specimens were collected in 23 localities. We have found 39 unique haplotypes. The minimum genetic diversity was found in D. c. vedenica, maximum in D. c. caucasica. All taxa of the complex, except for D. c. vedenica, demonstrate genetic heterogeneity. Four clades can be distinguished on the dendrogram of phylogenetic relationships. They correspond to D. alpina, D. c. caucasica, D. c. vedenica, D. daghestanica. D. c. caucasica forms two distinct haplogroups. On the phylogenetic tree, the sample of D. c. vedenica formed an independent clade close to D. c. caucasica. The Darevskia (caucasica) complex is polyphyletic according to the analysis of the mitochondrial marker. Nucleotide sequences of D. alpina formed a single clade with Darevskia (saxicola) complex representatives and combined with the sequences of D. brauneri into subclade. On the example of the population of D. daghestanica, found in a forest biotope without rocky outcrops and genetically not differing from individuals from the adjacent territory, the ability of rocky lizards to master biotopes unusual for them in a short period of time was demonstrated. This example demonstrates the ability of rock lizards to adapt to unusual biotopes in a short period of time. Genetic distance between D. c. vedenica and D. c. caucasica is comparable to the distance between D. c. caucasica and D. daghestanica. We assume the existence of an independent form of D. caucasica ssp. inhabiting South Ossetia and adjacent territories.

Comparative characteristics of the postcranial skeleton of Rock lizards from the Darevskia (caucasica) and Darevskia (saxicola) complexes

“…Надвидовой комплекс Darevskia (caucasica) в настоящее время включает 4 таксона видового и подвидового ранга: D. alpina (Darevsky, 1967), D. caucasica caucasica (Méhely, 1909), D. c. vedeni ca (Darevsky et Roitberg, 1999 и D. daghestanica (Darevsky, 1967); комплекс Darevskia (saxicola) -6 такcонов: D. arribasi Tuniyev, Petrova et Lotiev, 2023, D. brauneri brauneri (Méhely, 1909, D. b. my usserica Doronin, 2011, D. lindholmi (Szczerbak, 1962, D. saxicola (Eversmann, 1834) и D. szczerbaki (Lukina, 1963) (Доронин и др. [Doronin et al] 2013[Doronin et al] , 2021Tuniyev et al 2023). Оба комплекса недостаточно изучены в систематическом плане и могут быть признаны проблемными группами -в том числе по причине межвидовой гибридизации (Tarkhnishvili et al 2016;Tarkhnishvili and Iankoshvili 2023).…”

The mitochondrial phylogeography of the Crimean endemic lizard Darevskia lindholmi (Sauria, Lacertidae): Hidden diversity in an isolated mountain system

“…On the other hand, some populations or taxa from southern Caucasus are also questionable with their affiliation to particular Darevskia species complexes (Tarkhnishvili et al 2016). Currently, the assignment of D. alpina (Darevsky, 1967) to the aforementioned species complex or the D. caucasica complex is still a subject of discussion (Murphy et al 2000;Doronin et al 2021). Based on morphological data, D. lindholmi showed a close relationship to D. brauneri (Szczerbak 1962;Doro nin et al 2013), and moderate values for genetic distanc es based on cytochrome b between the Crimean and the Caucasian representatives of the complex (3.4-5.3%; Doronin et al 2013) indicate a PlioPleistocene time of divergence (see Tarkhnishvili et al 2016).…”

“…Based on morphological data, D. lindholmi showed a close relationship to D. brauneri (Szczerbak 1962;Doro nin et al 2013), and moderate values for genetic distanc es based on cytochrome b between the Crimean and the Caucasian representatives of the complex (3.4-5.3%; Doronin et al 2013) indicate a PlioPleistocene time of divergence (see Tarkhnishvili et al 2016). The genetic distances between most bi sexual Darevskia species are much higher (exceeding 10% ;Tarkhnishvili 2012;Ah madzadeh et al 2013;Kurnaz et al 2019;Doronin et al 2021). The highest diversity and uniqueness of satellite DNA discovered in D. lindholmi led to the assumption of a possible hybrid origin of the species (Grechko et al 2006).…”