Taxonomic Group Serpentes: The Evolution Of Diversity Between Species

Introduction:

From humble beginnings as single celled organisms, life on this planet has exploded into a plethora of diverse life of all shapes and sizes. All this change has been driven by evolution, the variation between organisms developing their own identities and populations all from one common ancestor (Campbell et al., 2014). But how did all this diversity arise? And how is it significant between organisms of the same species, and between other species? This essay will be exploring this topic using examples from the taxonomic group Serpentes, in order to explain and apply them to various concepts to help explore the topic.

Origin within species:

Diversity between individuals of a species arises through sexual reproduction. Due to the

This process is called speciation, and comes in two forms; allopatric, where populations become isolated from one another geographically, preventing gene flow that would homogenise the populations, allowing them to adapt to their different environments separately, and sympatric, where populations are not separated but develop into different species through isolating mechanisms such as behavioural and sexual incompatibility (Campbell et al,. 2014). An example of allopatric speciation is the Arizona Mountain Kingsnake, Lampropeltis pyromelana, a high altitude dwelling snake with populations separated by long distance and uninhabitable desert, with one population in Colorado Plateau and the other in the Sierra Madre Occidental. Both populations have been shown to have been isolated for a very long period of time with very distinct genetic lineages and unequal population sizes and stability, with suggestions made that a taxonomic revision to classify the populations as two separate species should be made due to allopatric speciation within the species (Burbrink et al.,

3 species; Philodryas nattereri, Oxyrhopus trigeminus, and Philodryas olfersii all prey upon the same species of mouse, Bolomys lasiurus. While all 3 snakes prey upon this species, each one has other species on which to prey which the others do not, for instance P. natterei and P. olfersii feed on various birds, lizards and anurans, while O. trigeminus also feeds on lizards, including species the other two do not feed on such as Trophiduras torquatus. Another species Collubridae occipitolutea, while sharing food sources with other snakes can also predate 2 other species of snake, Epicrates cenchria and Waglerophis merremii, which are not eaten by any other snake species in the area, avoiding competition for that particular food source (Vitt and Vangilder, 1983). This shows how even in the same taxonomic group ecological niches can develop and overlap, even creating predator and prey