Structuring in Psammophylax A Widespread African Snake Genus Cha - PowerPoint PPT Presentation

Phylogenetic Structuring in Psammophylax A Widespread African Snake Genus Cha Chad K d Kea eates tes, S , She hell lley ey Ed Edwar ards ds, , Wer erne ner Co r Conr nrad adie & C ie & Chris hris Kell elly

African Diversity • Africa= mega continent • 1600+ spp of reptile in Africa • Past research= morphologically orientated • Genetically understudied

Taxonomy • Conventional taxonomists can miss it • Scale counts, colour and size =‘plastic traits’ • Genetics can work with morphology & ecology • ‘Unified species concept’

Snake taxonomy

Psammophylax (Fitzinger 1843) • ‘Skaapstekers’ P. acutus P. variabilis • Small-medium sized • Seven species • Terrestrial • Diurnal P. r. rhombeatus P. multisquamis • Active hunters • Mildly venomous • Multiple sub-species P. tritaeniatus P. r. occelatus

Methods • Collect tissue samples • Produce molecular trees • Bayesian Inference • Extract DNA using salt • Maximum Likelihood extraction • Bayesian Codon • Amplify four genes • P-distance analysis • ND4 • Barcoding • CYTB • 16S • bGMYC • CMOS • 2D Morphometrics Ongoing

Psammophylax Psammophylax phylogenet phylogenetic t ic tree ee • P. rhombeatus and P. ocellatus are sister • Sub-species within P. variabilis is not a viable species

Psammophylax acutus

Psammophylax multisquamis 2

600 400 Frequency Pairwise Differences Frequency Pairwise Differences Intraspecific 350 500 intraspecific 300 Interspecific interspecific 400 250 300 200 Overlap 150 200 100 100 50 0 0 Sequence Divergences for Cytb (%) Sequence Divergences for ND4 (%) 400 600 intraspecies Frequency Pairwise Differences Frequency Pairwise Differences Intraspecific 350 500 interspecies Interspecific 300 400 250 300 200 No Overlap 150 200 100 100 50 0 0 Sequence Divergences for Cytb (%) Sequence Divergences for ND4 (%) Figure 3 : Uncorrected Pairwise Distances from Table 2 used to illustrate the barcode gap between intra- and inter-species sequence divergences values. A- Cytb with currently accepted taxonomy of the genus; B- Cytb with newly proposed taxonomy of the genus; C- ND4 with currently accepted taxonomy of the genus; D- ND4 with newly proposed taxonomy of the genus. The grey bar denotes the barcode gap, the gap between the intra- and inter- species variation

Conc Conclusion lusion • Improved understanding of Psammophylax inter- species relationships • Uncovered new species • Resolved taxonomy

THANK YOU A big thank you to everyone who has helped with sample collection thus far.