Understanding the generation and maintenance of diversity—both in lineages and traits—is a central goal of macroevolutionary research. Hemidactylus geckos are well-suited for exploring such questions due to their remarkable species richness and trait variation. Despite their potential, studies on the broader patterns within the genus are rare. My thesis fills this gap by dwelling into key macroevolutionary processes such as biogeography, diversification, and trait evolution in Hemidactylus by utilizing various phylogenetic comparative methods.

In chapter one, I reconstruct the most updated global phylogeny of Hemidactylus geckos using coalescent and concatenation-based methods. Further, I unravel their disputed biogeographic origins and highlight the intercontinental dispersal events that may have shaped the current diversity and distribution of the genus.

Chapter two utilizes a trait-based approach to explain the contrasting pattern of species richness and distribution between Hemidactylus and its sister genus Dravidogecko. I evaluate the effect of various abiotic and morphological characters on the dispersal ability and diversification rates of these two groups.

In Chapter three, I seek to investigate the impact of habitat use on body size and morphological evolution of the genus. I use various trait evolution models to determine whether habitat filtering drives size variation, and further attempt to quantify the strength of selection.

Finally, chapter four focuses on the ecological and evolutionary dynamics of host-parasite interactions between Hemidactylus geckos and their ectoparasitic mites. I ask whether mite communities are predominantly shaped by host phylogeny or geography, and further attempt to uncover the ecological correlates of mite loads in these geckos.

These research questions thus offer a multifaceted understanding of the evolutionary forces driving the complex trajectories of such widely distributed, highly speciose taxa.