Taxonomy is the science of naming, describing and classifying organisms. Scientists who do this are called taxonomists. Their work includes describing and naming new species, deciding which group each organism belongs in, and revising groups when new evidence appears.The system of classification still used today was devised in the 18th century by the Swedish botanist Carl Linnaeus. Linnaeus grouped organisms by their observable physical features, their morphology.Morphology alone can be misleading. Unrelated organisms living in similar environments may evolve similar features independently, which is called convergent evolution. For example, sharks and dolphins both have streamlined bodies and fins, but sharks are fish and dolphins are mammals.Modern taxonomists therefore use several kinds of evidence together:
• morphology and anatomy, including internal structures
• embryology (how organisms develop)
• physiology, biochemistry and behaviour
• molecular evidence, comparing the base sequences of DNA and the amino acid sequences of proteins between species.Taxonomy is not fixed. When new evidence is found, groups are revised. Before a new species or a new classification is accepted, the evidence is published in a scientific journal after peer review, in which other experts check the methods and conclusions. Other scientists can then test the findings for themselves.
• morphology and anatomy, including internal structures
• embryology (how organisms develop)
• physiology, biochemistry and behaviour
• molecular evidence, comparing the base sequences of DNA and the amino acid sequences of proteins between species.Taxonomy is not fixed. When new evidence is found, groups are revised. Before a new species or a new classification is accepted, the evidence is published in a scientific journal after peer review, in which other experts check the methods and conclusions. Other scientists can then test the findings for themselves.