Friday 24 October 2014

When does a reptile stop becoming a reptile? Now perhaps.

This may seem like a rather curious question to ask but the new evidence that birds evolved from reptiles might just change that fact. To understand this in greater detail we need to look at what scientists call taxonomy, this describes how we categorize animals into varies groups such as mammals, amphibians, birds and reptiles. Animals were first categorized in the 18th century by Carl Linnaeus and was based on how animals looked leading to six classes: mammalia, birds, amphibians, fishes, insects and worms then, as time passed amphibians was split into two groups: reptiles and serpents meaning, that amphibians and non snake like reptiles were based in the same group which is clearly as we now know incorrect and by the 19th century it had changed again into the four groups we know today: mammals, birds, reptiles and amphibians, yet even to this day scientists still find themselves re-categorizing various species as new information is found.



The diagram above shows the evolutionary relationships and therefore classifications of the group we ourselves belong to called Tetrapoda meaning four limbed. As you can see they are various branches erupting from the main stem with each junction demonstrating a common ancestor i.e caecillians and frogs and toads share a common ancestor therefore, when you follow the evolutionary path for reptiles you find that birds should be included and not be a separate group. Here is where a problem that is currently plaguing taxonomists arises; birds and reptiles are currently seen as two separate groups, how do we now approach possibly merging these groups together and what do we call it. Now both reptiles and birds do fall under a classification used by science called Sauropsida whilst mammals are classed as Synapsids and are grouped as such due to differences in skull morphology therefore, the name reptile could be replaced by this but for most this would be a bit of a mouthful but regardless of what name is eventually chosen it seems that soon the word reptile will be part of a forgotten ancient history. To read original article please click here
 
Those of you who are regular visitors to my blog will have noticed that quite a bit of time elapsed between this post and the last; I do apologize for this but in-between second year university work and other commitments it can be hard to find time to contribute to this but I do aim to continue on with the blog and will try to post as often as I can; anyways as always please feel free to add your views on this topic in the comments box below, I always look forward to hearing from you all.