In [[biology]], a '''species''' is one of the basic units of biological classification (see the diagram at the side - a [[genus]] contains one or more species, etc.) A usable definition of the word "species" and reliable methods of identifying particular species are essential for stating and testing biological theories and for measuring [[biodiversity]]. A species consists of individual organisms which are very similar in appearance, anatomy, physiology and genetics. Evolutionists assume this is due to having relatively recent common ancestors. Traditionally, multiple examples of a proposed species must be studied for unifying characters before it can be regarded as a species. | In [[biology]], a '''species''' is one of the basic units of biological classification (see the diagram at the side - a [[genus]] contains one or more species, etc.) A usable definition of the word "species" and reliable methods of identifying particular species are essential for stating and testing biological theories and for measuring [[biodiversity]]. A species consists of individual organisms which are very similar in appearance, anatomy, physiology and genetics. Evolutionists assume this is due to having relatively recent common ancestors. Traditionally, multiple examples of a proposed species must be studied for unifying characters before it can be regarded as a species. |