Classification Systems Explained

People have been studying the natural environment since the days of Aristotle and we have learned much about organisms by watching, dissecting and studying them. Humans have a natural tendency to organise and put things into groups, this includes the natural environment and the organisms around us.

We have developed several systems in order to understand the relationships between organisms and also to allow us to clearly talk about the same species! In some cases, scientists have been studying a species for years only to find out that they were looking at two distinct organisms! Classification allows us to avoid this confusion and allow the gradual progression of science to add to the bank of knowledge about our world.

The distinction between two species can be as small as a slight difference in the noise they make. Species of birds have been officially identified this way after computers and software have enabled close analysis of bird calls and scientists have been able to distinguish between two species. These investigations can later be followed up with genetic analysis which can conclusively demonstrate the differences between species. 

Remember that evolution drives species towards developing new adaptions, suited to the biotic and abiotic conditions that they experience. These changes can be large or small, from growing wings to slight changes in cell structure and function. Our efforts to classify these changes help us paint a big picture view of evolutionary changes and speciation over time.

Scientists who identify and classify new species are known as taxonomists and their role is to examine the evidence which suggests which of the groups we have invented an organism best fits into. Unfortunately, organisms often defy classification and this has led to new proposals for classification systems over the years. Algae are a good example of this where they are thought to fit into multiple kingdoms at once despite their shared name. The tools that taxonomists have developed over the years have caused several shake-ups and misclassifications. In some cases, where animals that were thought to be closely related due to their similar features and their biogeographical overlaps, have actually turned out to be distant cousins. Phylogenetics is one of the most recent developments in the taxonomist’s toolkit which is also the most powerful. This field attempts to classify the evolutionary relationships between species by using DNA analysis to establish the amount of DNA that is similar between organisms. Phylogenetics allows taxonomists to supplement their classifications with modern analysis which often produces surprises. Other tricks such as looking to neighbouring tectonic plates for closely related species can also be fruitful. 

This is an ancient field that has undergone a revolution in the past 200 years, thanks to the works of many historical figures such as Charles Darwin who is largely credited with understanding the concept of evolution by natural selection. Carl Linnaeus also pioneered the classification system which we still use today and more modern contributions from Watson and Crick for discovering the double-helix shape of DNA. Step by step we make our way towards a more complete and accurate library of species which we can use to advance our efforts in conservation. After all, engineers, medical scientists and filmmakers alike have been inspired and gifted with the natural variety of the Earth.