Eocene-Oligocene cooling and the diversification of Hemidactylus geckos in Peninsular India

The Eocene-Oligocene cooling marks a global shift towards a cooler and drier climate, concurrent with significant turnover in biota globally. In Peninsular India, palynological investigations suggest a shift from wet rainforest vegetation to dry and seasonal species during this period. However, the grassland and open habitats that dominate this region at present expanded relatively recently due to Late Miocene intensification of monsoon seasonality. We test the possible role of these climatic shifts in generating the dry habitat diversity of an endemic radiation of Hemidactylus geckos distributed in both wet and dry habitats, by investigating whether (a) the beginning of the diversification of dry habitat lineages overlap with the Eocene-Oligocene cooling or late Miocene aridification and (b) accompanied by an increase in diversification. Molecular data (two nuclear and two mitochondrial gene fragments) were generated for samples collected across Peninsular India, and along with previously published data, a time-calibrated phylogeny was reconstructed. Ancestral state reconstruction of dry and wet habitat states was carried out on the time-calibrated phylogeny and gamma-statistics along with a test for diversity-dependent diversification utilized to examine the trend in lineage accumulation. Results show the ancestral node of this radiation to have a dry habitat state, which began diversifying between 39 and 32 million years ago, concurrent with the Eocene-Oligocene cooling. Furthermore, lineage diversification fit a diversity-dependent model of diversification and the gamma-statistics revealed an early increase in diversification followed by a slow-down later. The deep divergences of dry habitat lineages concurrent with the Eocene-Oligocene cooling suggest that this could have served as an ecological opportunity facilitating an early increase in lineage diversification of Hemidactylus in this region. These results suggest an ancient origin and long persistence of arid ecosystems in Peninsular India

Molecular data in conjunction with morphology help resolve the Hemidactylus brookii complex (Squamata: Gekkonidae)

Molecular data are increasingly being used to resolve cryptic species complexes; however, subsequent formal species description and taxonomic revisions often remain incomplete. Given that most species are described based on morphology-based alpha taxonomy, one cannot resolve nomenclatural issues of species complexes without the aid of morphology. In this study, we examined the taxonomic status of a long-known human commensal and species complex, Hemidactylus brookii. To this end, samples of H. cf. brookii and related species were collected across India. We analyzed molecular as well as morphological data to resolve the taxonomy of this species complex. Seven deeply divergent, well-supported clades were recovered using the mitochondrial phylogeny, five of which were also retrieved in the nuclear tree. One of these consists of five morphologically distinct species of ground-dwelling Hemidactylus. The genetic distances across each clade of putative species of H. brookii sensu lato were comparable to that between morphologically distinct species of ground-dwelling Hemidactylus. Meristic characters such as number of precloacal-femoral pores, number of non-pore bearing scales interrupting the series of pored scales, dorsal pholidosis, and presence/absence of divided lamellae can be used to distinguish these putative species from each other. However, morphological characters of H. brookii sensu stricto did not correspond to any of the putative species studied. The study also revealed that the ``H. brookii complex'' in India includes two commensal species, Hemidactylus parvimaculatus and Hemidactylus murrayi. Furthermore, these two lineages have independently acquired adaptations that could have assisted them in exploiting human habitat. An identification key to diagnose species within this complex and rest of the Hemidactylus in India is proposed

A novel member of the Hemidactylus brookii complex (Squamata: Gekkonidae) from the Western Ghats of Maharashtra, India

Chaitanya, R., Agarwal, Ishan, Lajmi, Aparna, Khandekar, Akshay (2019): A novel member of the Hemidactylus brookii complex (Squamata: Gekkonidae) from the Western Ghats of Maharashtra, India. Zootaxa 4646 (2): 236-250, DOI: https://doi.org/10.11646/zootaxa.4646.2.

Two new species of yellow-tailed Hemidactylus Goldfuss, 1820 (Squamata Gekkonidae) from rocky outcrops on the Telangana Plateau, India

Lajmi, Aparna, Giri, Varad B., Singh, Taneraw, Agarwal, Ishan (2020): Two new species of yellow-tailed Hemidactylus Goldfuss, 1820 (Squamata Gekkonidae) from rocky outcrops on the Telangana Plateau, India. Zootaxa 4895 (4): 483-504, DOI: https://doi.org/10.11646/zootaxa.4895.4.

A new rock dwelling Hemidactylus (Squamata: Gekkonidae) from Chhattisgarh, India

A distinct new species of gecko of the genus Hemidactylus is described from the Kanker district of Chhattisgarh State, east-central India. This large-sized (SVL average 81.33 +/- 13.40 to at least 98.0 mm) Hemidactylus is characterized by a dorsum with small granules, intermixed with 10-12 rows of irregularly arranged, slightly larger, rounded, weakly-keeled tubercles at midbody; 10-12 and 13-15 subdigital lamellae on the first and fourth digits, respectively, of both manus and pes; a single enlarged postcloacal tubercle on either side of the tail; 10-12 femoral pores on each thigh separated by 5-8 poreless scales; 12-14 supralabials and 10-12 infralabials

A new rock dwelling Hemidactylus (Squamata: Gekkonidae) from Chhattisgarh, India

A distinct new species of gecko of the genus Hemidactylus is described from the Kanker district of Chhattisgarh State, east-central India. This large-sized (SVL average 81.33 +/- 13.40 to at least 98.0 mm) Hemidactylus is characterized by a dorsum with small granules, intermixed with 10-12 rows of irregularly arranged, slightly larger, rounded, weakly-keeled tubercles at midbody; 10-12 and 13-15 subdigital lamellae on the first and fourth digits, respectively, of both manus and pes; a single enlarged postcloacal tubercle on either side of the tail; 10-12 femoral pores on each thigh separated by 5-8 poreless scales; 12-14 supralabials and 10-12 infralabials

A new rock dwelling Hemidactylus (Squamata: Gekkonidae) from Chhattisgarh, India

Murthy, B. H. C. K., Bauer, Aaron, Lajmi, Aparna, Agarwal, Ishan, Giri, Varad B. (2015): A new rock dwelling Hemidactylus (Squamata: Gekkonidae) from Chhattisgarh, India. Zootaxa 4021 (2): 334-350, DOI: http://dx.doi.org/10.11646/zootaxa.4021.2.

Evolutionary genomics of socially polymorphic populations of Pogonomyrmex californicus

Errbii M, Ernst UR, Lajmi A, Privman E, Gadau J, Schrader L. Evolutionary genomics of socially polymorphic populations of Pogonomyrmex californicus. BMC Biology. 2024;22(1): 109.**Abstract** **Background** Social insects vary considerably in their social organization both between and within species. In the California harvester ant,Pogonomyrmex californicus(Buckley 1867), colonies are commonly founded and headed by a single queen (haplometrosis, primary monogyny). However, in some populations in California (USA), unrelated queens cooperate not only during founding (pleometrosis) but also throughout the life of the colony (primary polygyny). The genetic architecture and evolutionary dynamics of this complex social niche polymorphism (haplometrosis vs pleometrosis) have remained unknown. **Results** We provide a first analysis of its genomic basis and evolutionary history using population genomics comparing individuals from a haplometrotic population to those from a pleometrotic population. We discovered a recently evolved (chameau) and DNA methylation (Dnmt1). **Conclusions** Altogether, our results suggest that social morph in this species is a polygenic trait involving a potential young supergene. Further studies targeting haplo- and pleometrotic individuals from a single population are however required to conclusively resolve whether these genetic differences underlie the alternative social phenotypes or have emerged through genetic drift. </p