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

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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


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SLIDE 1

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

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SLIDE 2

African Diversity

  • Africa= mega continent
  • 1600+ spp of reptile in Africa
  • Past research= morphologically
  • rientated
  • Genetically understudied
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SLIDE 3

Taxonomy

  • Conventional taxonomists

can miss it

  • Scale counts, colour and

size =‘plastic traits’

  • Genetics can work with

morphology & ecology

  • ‘Unified species concept’
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SLIDE 4

Snake taxonomy

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SLIDE 5

Psammophylax (Fitzinger 1843)

  • P. tritaeniatus
  • P. acutus
  • P. multisquamis
  • P. r. rhombeatus
  • P. variabilis
  • ‘Skaapstekers’
  • Small-medium sized
  • Seven species
  • Terrestrial
  • Diurnal
  • Active hunters
  • Mildly venomous
  • Multiple sub-species
  • P. r. occelatus
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SLIDE 6

Methods

  • Collect tissue samples
  • Extract DNA using salt

extraction

  • Amplify four genes
  • ND4
  • CYTB
  • 16S
  • CMOS
  • Produce molecular trees
  • Bayesian Inference
  • Maximum Likelihood
  • Bayesian Codon
  • P-distance analysis
  • Barcoding
  • bGMYC
  • 2D Morphometrics Ongoing
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SLIDE 7

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

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SLIDE 8

Psammophylax acutus

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SLIDE 9

Psammophylax multisquamis 2

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SLIDE 10

Overlap No Overlap

100 200 300 400 500 600

Frequency Pairwise Differences Sequence Divergences for ND4 (%)

Intraspecific Interspecific 50 100 150 200 250 300 350 400

Frequency Pairwise Differences Sequence Divergences for Cytb (%)

intraspecific interspecific 100 200 300 400 500 600

Frequency Pairwise Differences Sequence Divergences for ND4 (%)

Intraspecific Interspecific 50 100 150 200 250 300 350 400

Frequency Pairwise Differences Sequence Divergences for Cytb (%)

intraspecies interspecies

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

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SLIDE 11

Conc Conclusion lusion

  • Improved

understanding of Psammophylax inter- species relationships

  • Uncovered new species
  • Resolved taxonomy
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SLIDE 12

THANK YOU

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