Taxonomy

Taxonomy is the hierarchical classification of living organisms based on similarities in characteristics.

Taxonomy is often confused with Phylogeny, which also classifies living organisms, but by evolutionary relationships, rather than by characteristics.

For example, in Taxonomy, reptiles, birds and mammals are separate and equal classes of vertebrates; in Phylogeny, reptiles and birds are grouped together as they have common reptilian ancestors, so birds / reptiles together are an equivalent group to mammals.

In spite of understanding the concept as described above, I sometimes do get rather confused by it when it comes down to the two different systems of classification of a particular species!

A basic example of a taxonomic hierarchical classification (there are a few other subdivisions, but I don’t want to overcomplicate it unnecessarily here), using humans as the example species; as you can see, characteristics get more specific the closer it gets to ‘species’:

• Kingdom – Animalia (they are animals)
• Phylum – Chordata (they have a spine)
• Class – Mammalia (they are mammals)
  
• Order – Primates (these include apes, gibbons, monkeys, tarsiers, lemurs and lorises)
• Family – Hominidae (chimpanzees, orangutans, gibbons and gorillas are included at this level – we are more closely related to these than we are to monkeys, tarsiers, lemurs and lorises )
• Tribe – Hominini (chimpanzees are included at this level – we are more closely related to chimpanzees than to gorillas, orangutans and gibbons)
• Genus – Homo (includes other species of early man, but not chimpanzees)
• Species – Homo sapiens (us – though some are more sapiens than others!)