A Molecular Approach to the Phylogeny of Theraphosidae and Their Kin

Abstract

Molecular data are increasingly helping inform tarantula evolutionary history. This includes redefining taxonomic groups at many levels, from clarifying species limits and matching sexes to elucidating the boundaries of genera and higher taxonomic ranks. We initially overview early molecular studies with tarantulas, before more closely looking at later developments with either a focus on questions around the population–species interface, or on aspects of the broader phylogeny. In both, we consider the gene fragments used for insights, but also introduce the role that newer high-throughput sequencing can play to expand the scope of such datasets. We then move into other approaches offered by the age of genomics, with some focus on mitogenomics versus nuclear genomics. Here we discuss some useful aspects of genomes such as gene arrangements that may be treated as “rare-events” to resolve intractable systematic questions. We then overview transcriptomic methods versus target capture approaches, each of which provide increasingly powerful methods for new insights. Finally, we speculate on where additional taxon sampling is needed to resolve the tarantula phylogeny, before concluding how existing studies now form a solid baseline for future projects, in particular on biogeography or the evolution of body size, venom, or other interesting comparative questions.