Science at a Distance

Classification
Introduction
CLAS Why Classify?

Humans like to bring order out of chaos. Most of us don't like to see a jumbled mess of clothes lying on the floor. We put socks in the sock drawn, shirts on hangers arranged by color or day of the week, words in alphabetical order, lists of task by order of priority, and pans in cupboards in strict order of size. Nature can be messy, grass and weeds seem to grow everywhere, but humans like square, clean edges to their lawns.

Faced with the problem of bringing order to chaos of diversity of species we see in nature, humans have long sort to find patterns within the seemingly random way in which one species relates to another species, and both of them relate to their relatives in the distant past. There has to be some pattern, we keep telling ourselves, like a neat sock draw, if only we could find it.

Unfortunately nature isn't listening and simply goes on in its own random way. However, despite many setbacks, human scientists still feel the need to try and organize species into meaningful arrangements that they hope will tell them something about their subjects, or reveal some new insights into where they came from.

Classification fills a very human need to impose order on nature and find hidden relationships. By grouping organisms and species together it was originally hoped that huge masses of data could be stored and retrieved more easily. Knowledge about a species could be saved and recovered in a logical manner. Later it was seen that a good classification system would also help determine evolutionary relationships between species and even make it easier to see if, when and where new species were arising. So the hunt for a useful and unambiguous classification system continued.

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CLAS Prerequisites

Any classification system requires four things:

Data or evidence For every object or organism to be classified, a lot of information is needed. This data is usually provided by systematics; an examination of organisms from many points of view. Such data can include input from almost all fields of science, including molecular biology, field studies, collections, morphological analysis, genetics, behavioral studies, chemistry, and anatomy. A systematic study, at its best, generates a very large amount of data about organisms which can then be used to determine the range of similarities and differences between them.

The appropriate groups Taxonomy is a theoretical branch of biology in which taxonomists try to devise appropriate groups into which they can unambiguously place all living things. All taxonomies start from first principles; now do the groups relate to one another? Is it a structural relationship, evolutionary relationship, or even a ecological relationship? Taxonomies also have rules and procedures that must be followed during their use. Agreed names The nomenclature used when naming the individual species and groups must be distinctive, unambiguous and agreed upon by all users. It must be universal and adopted by scientists everywhere in the world.

Process and Priorities Once the evidence is in and the taxonomy agreed, individual species must find their way into the appropriate groups. Classification in Biology depends on users agreeing on the principles of how this should be done (process) and what features of a species or process receives the higher priority when difficulties arise. For example, are structural or ancestral factors paramount?


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Science at a Distance
© 1998 Professor John Blamire