>>In layman's terms (since I know very little about taxonomy and don't comprehend much of the scientific articles on the subject), could someone please explain the current hypothesis (multiple hypotheses?) about how Atractaspis (stiletto snakes) evolved and what other current snakes are most closely related to them? They seem like pretty interesting snakes.>>



It is difficult to figure out how a species may have evolved. History cannot be observed directly. Even recent human history is often shrouded in mystery. Keeping that in mind, scientists can use different facts to find out which species are the closest relatives of Atractaspis. These facts include morphology, behavior, geography and of course protein and DNA similarities to other species. Different facts may result in different hypothesis being proposed, so often there is no scientific consensus.



There is one paper which places Atractaspis in the Elapidae, which is a family that includes the coral snakes, cobras, and venomous sea snakes. The authors of this paper point out that some authors have classified Atractaspis as a viperid, a colubrid snake or an independent lineage by other taxonomists in the past. But since vipers, elapids and colubrids are closely related families of snakes, this sort of disagreement is not surprising. Heise et al.'s tree places Atractaspis as the sister taxon (closest relative) of the genus Bungarus, snakes that are commonly known as kraits.



Reference:

Philip J. Heise, Linda R. Maxson, Herndon G. Dowling, and S. Blair Hedges 1994. Higher-Level Snake Phylogeny Inferred from Mitochondrial DNA Sequences of 12s rRNA and 16s rRNA Genes. Molecular Biology and Evolution, Vol 12, 259-265.

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