The Evolution of Pythons and their Convergence with Boas

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1. Summary

Convergent evolution is the repeated origin of similar species or traits, usually driven by adaptation to the same conditions. It can be seen for example in how sharks and dolphins, or bats and birds, have evolved very similar body plans and morphologies. This happened because they adapted to the same life style. Convergent evolution can sometimes happen between two groups instead of individual species, like has been reported in some lizard and fish groups. During my Masters I demonstrated that this is exactly what happens between two of the most well-known snake familes; the pythons and the boas. Pythons and boas adapted to the same ecology have evolved the same head shape. Now in my PhD I want to have a closer look at different aspects of their biology and see how have these features evolved and if they are indeed convergent. 

2. Description

Pythons, as few people actually know, are most diverse in Australia, having 75% of their species and most of their morphological en ecological diversity on this continent. Boas are widespread around the world, but are especially diverse in the Americas. Several interesting things have indendently originated in both pythons and boas. Both groups show forms adapted to arboreality, aquatic habitats, burrowing and terrestriality. Gigantism (like the 10 meter long anaconda and reticulated python) and dwarfism (like the less than 60 cm pigmy python and sand boas) have repeatedly evolved in both families, so the evolution of body size is of great interest. Heat sensitive pits, which are specialized organs located around their mouths that provide them infrared vision have also arised independently in pythons and boas. All these provide excellent questions that have much broader implications in the understanding of evolutionary mechanisms. What makes evolution predictable and repeatable, what are the optimum paths evolution takes for solving problems.

For this I first need to reconstruct the evolutionary history of pythons and boas, to have a historic framework. You need to know the evolutionary relationships between the species in order to make clear conclusions. This will be done with a fresh dataset of hundreds of genes for each species, which is done with very recently developed methods and its truly on the frontier of science. Then I need to collect data from museum specimens all around Australia and potentially USA and Europe, this data will include different sorts of morphological measurements like size, heat pit shape, etc... I also need to CT scan skulls for all the species because this is the structure in a legless animal like a snake that will be more strongly subjected to natural selection. Collecting all these data is expensive, so in order to make this study as good as I wish it to be I need funding.



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I was born in Santiago, Chile in 1988. Since I have memory I have always been incredibly attracted to nature, especially creatures like reptiles, amphibians and insects. I did my Bachelor's degree ...