2024 genomic study on cobra Asian origins

As long-time readers know,
two of the biggest problems in phylogenetics are 1) taxon exclusion and 2) genomic studies (which also exclude taxa because they exclude fossils).

This time neither come into play.

According to the publicity from LiveSceince.com
“Scientists once believed that Elapoidea, the superfamily containing cobras, coral snakes and mambas, originated in Africa. A fossil of a file snake found in Tanzania and dated to the Oligocene Epoch (33.9 million to 23 million years ago) supported this hypothesis — it is the oldest relative of this group discovered in the fossil record.”

“But in new research, published Aug. 7 in the journal Royal Society Open Science, researchers used genetic analysis and fossils from other regions to conclude that these snakes, as well as snakes in the related superfamily Colubroidea, actually originated in Asia.”

The Weidell et al 2024 genomic cladogram
is shown in figure 1. They wrote, “”We developed a novel suite of genomic resources, included worldwide sampling, and inferred a robust estimate of evolutionary relationships, which we leveraged to quantitatively estimate geographical range evolution through the deep-time history of this remarkable radiation.”

Deep time genomic studies sometimes match trait studies. Sometimes.

“Our phylogenetic and biogeographical estimates of historical ranges definitively reject a lingering former ‘Out of Africa’ hypothesis and support an ‘Out of Asia’ scenario involving multiple faunal exchanges between Asia, Africa, Australasia, the Americas and Europe.”

The African Oligocene fossil taxon mentioned above in the publicity cannot be tested in the Weidell et al genomic study, but chronologically it can be accounted for. See below.

Figure 1. Cladogram fro Weidell etal 2024 based on genomics and focused on cobra ancestry. Not included are two Elapids: Atractaspsis, from Africa, and Aipysurus, a sea snake.  However note the inclusion of Aparallactus, also from Africa, a member of the Atractaspididae.. Yellow taxa are also tested in the LRT. Naja naja is the Indian cobra. ” data-image-caption=”

Figure 1. Cladogram fro Weidell etal 2024 based on genomics and focused on cobra ancestry. Not included are two Elapids: Atractaspsis, from Africa, and Aipysurus, a sea snake.  However note the inclusion of Aparallactus, also from Africa, a member of the Atractaspididae.. Yellow taxa are also tested in the LRT. Naja naja is the Indian cobra.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/cobra.cladogram.weidell2024-588-1.jpg?w=164″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/cobra.cladogram.weidell2024-588-1.jpg?w=561″ tabindex=”0″ role=”button” class=”size-full wp-image-88161″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/cobra.cladogram.weidell2024-588-1.jpg” alt=”Figure 1. Cladogram fro Weidell etal 2024 based on genomics and focused on cobra ancestry. Not included are two Elapids: Atractaspsis, from Africa, and Aipysurus, a sea snake.  However note the inclusion of Aparallactus, also from Africa, a member of the Atractaspididae.. Yellow taxa are also tested in the LRT. Naja naja is the Indian cobra.” width=”584″ height=”1066″ />

Figure 1. Cladogram fro Weidell etal 2024 based on genomics and focused on cobra ancestry. Not included are two Elapids: Atractaspsis, from Africa, and Aipysurus, a sea snake.  However note the inclusion of Aparallactus, also from Africa, a member of the Atractaspididae.. Yellow taxa are also tested in the LRT. Naja naja is the Indian cobra.

Comparisons to the LRT
(Fig 2) are useless because the only taxa the two studies have in common are Boa and Crotalus, the rattlesnake. The LRT includes no cobras, but it does include another venomous elapid, the sea snake, Aipysurus, which is not listed in the Weidell et al study. Atractaspis in the LRT is an elapoid, not an elapid.

These substitute taxa make the Weidell et al claodgram and the LRT match.

Figure 1. Subset of the LRT focusing on snakes and their ancestors including tested gekkos.

” data-image-caption=”

Figure 1. Subset of the LRT focusing on snakes and their ancestors including tested gekkos.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/10/snake_ancestors2022-588.jpg?w=194″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/10/snake_ancestors2022-588.jpg?w=584″ tabindex=”0″ role=”button” class=”size-full wp-image-73354″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/10/snake_ancestors2022-588.jpg” alt=”Figure 1. Subset of the LRT focusing on snakes and their ancestors including tested gekkos.” width=”584″ height=”902″ />

Figure 1. Subset of the LRT focusing on snakes and their ancestors including tested gekkos. Boa is the boa. Crotalus is the rattlesnake. Atradtaspis is the stilleto snake from Africa. Aipysurus is the sea snake, not mentioned in the Weinell et al text or cladogram.. Cobras are not tested in the LRT.

References
Weinell JL et al (3 co-authors) 2024. Novel phylogenomic inference and ‘Out of Asia’ biogeography of cobras, coral snakes and their allies. Royal Society Open Science. https://doi.org/10.1098/rsos.240064.

Publicity
livescience.com/animals/snakes/cobras