Phylogeography, historical demography and systematics of the world’s smallest pythons (Pythonidae, Antaresia)

Advances from empirical studies in phylogeography, systematics and species
delimitation highlight the importance of integrative approaches for
quantifying taxonomic diversity. Genomic data have greatly improved our
ability to discern both systematic diversity and evolutionary history.
Here we combine analyses of mitochondrial DNA sequences, thousands of
genome-wide SNPs and linear and geometric morphometrics
on Antaresia, a clade of four currently recognised dwarf
pythons from Australia and New Guinea (Antaresia childreni, A. stimsoni,
A. maculosa and A. perthensis). Our integrative analyses
of phylogenetics, population structure, species delimitation, historical
demography and morphometrics revealed that the true evolutionary diversity
is not well reflected in the current appraisal of the diversity of the
group. We find that Antaresia childreni and A.
stimsoni comprise a widespread network of populations connected
by gene flow and without evidence of species-level divergence among them.
However, A. maculosa shows considerable genetic
structuring which leads us to recognise two subspecies in northeastern
Australia and a new species in Torres Strait and New Guinea. These two
contrasting cases of over and under estimation of diversity, respectively,
illustrate the power of thorough integrative approaches into understanding
evolution of biodiversity. Furthermore, our analyses of historical
demographic patterns highlight the importance of the Kimberley, Pilbara
and Cape York as origins of biodiversity in Australia.