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Rules of Classification of Taxonomy

In the mid 1700s, a Swedish physician and botanist named Carolus Linnaeus devised the beginnings of taxonomy. He classified different animal and plant species by their reproductive organs. Taxonomy was furthered by the work of Charles Darwin. The taxonomic system we know now was based on Darwin's theory of evolution.

Kingdom
- Kingdom is the broadest classification of the 300,000 species of plants and one million species of animals on earth. There are five kingdoms, the animal kingdom, the plant kingdom, the fungi kingdom, the protist kingdom and the moneran kingdom. Humans are listed as the first in the animal kingdom. The kingdom is the least specific of the taxonomic classifications. As you get further down the chain of classifications, the groupings get more specific.
Phylum and Divisions
- The animal, protist and moneran kingdoms are next classified by phyla; plants and fungi are separated into divisions. The animal kingdom has 10 phyla: chordate, arthropod, mollusk, annelid, rotifer, nematode, tardigrade, cnidarian, echinoderm and platyhelminthes. Humans belong to the chordate phylum as do fish, birds and reptiles. The animal kingdom has the most phyla. Some of the divisions in the plant kingdom include magnoliophyta, which contains all flowering plants, and pteridophyta, which contains plants with roots and stems that do not flower.
Class and Order
- More specific than the phyla or the divisions are the classes. Species from the same phylum that are more similar to each other are then placed in the same class. Humans and other animals that produce milk to nurse their offspring belong to the mammalia class. Those species in the same class that are still more similar to each other belong to the same order. Humans belong to the primata order. Monkeys also belong to the primata order, supporting the theory that man evolved from primates.
Family and Species
- Orders that have much in common are then divided into families. There are still less species in a family than in an order or phylum. Humans belong to the order hominidae as do other human-like species. Members of the orders are called species. Two creatures are considered to be of the same species if they would naturally mate with each other and produce offspring. Homo sapiens, or humans, are the only remaining species of their kind. Species is the most specific taxonomic classification.

Animals & Science