History of Classification

By Karly Kandel

350 BC Aristotle

Aristotle was a Greek Philosopher and biologist was the first to classify animals on their structural similarities and made detailed observations of marine, organisms. Classified animals based on their means of transportation. Used contemporary classification systems and divided animals based on wither they had blood or not, at least not red blood. The blood animals that had vertebrates where then classified within five genera’s: mammals, birds, reptiles & amphibians, fish, and whales.

300 BC Theophrastus

Theophrastus was a student of Aristotle. He wrote Inquiry into Plants, where he applied a lot of Aristotle’s taxonomic approach to the study of plants. Theophrastus divided plants up based on shaped to more detailed categories herbs, trees, shrubs.

1517-1564 Pierre Belon

Pierre Belon study and cataloged birds extensively. Belon was the first to use adaptation to habitat to divide birds into such groups as aquatic birds, wading birds, birds of prey, perching birds, and land birds, which still can be found in informal use today.

1519-1603 Andrea Cesalpino

Andrea Cesalpino was the first to classify plants according to structural characteristics like seeds and fruits. At the University of Pisa were he wrote some works called De Plantis. A lot of Andrea Cesalpino’s work was based off Aristotle’s works.

1660 John Ray

John Ray was the first to character weighting method to structural features in animals. For example classifying birds, he would use characteristics, the shape and size of the bird’s beak. Some of his works were Catalogue of Cambridge Plants and Synopsis Methodica Avium et Piscium which had systematic works on plants, birds, mammals, fish, and insects. He was the first to classify flowers into monocots and dicots.

Mid 1700's Carolus Linnaeus

Linnaeus was a Swedish botanist he published Systema Nature used morphology for arranging specimens in collections. Divided the animals kingdoms into species into genera, genera into order, in order to classify. Much of his classifications is now drastically altered, but the basic principles of his scheme are still followed.

1859 Charles Darwin

Charles Darwin argued in his work On the Origin of Species that species should be related based on ancestry. That groups and species have diverged from a shared ancestor, they will have similar characteristics. There were problems getting people to except the fact because they didn’t believe that it all needed to be based just upon evolutionary history.

1950’s Robert H. Whittaker

Robert H. Whittaker he proposed adding a fifth kingdom, the kingdom of fungi. Fungus was originally classified as a plant. Whittaker said that fungus do not make their own food like plants. They also do not ingest their food like animals, so there for they should have their own kingdom.

1970's Carl Woese

Carl Woese believed that the kingdom that was classified as bacteria needed to be split up into two separate kind archaebacteria and Eubacteria. Archaebacteria, were found to have unique molecular structures and physiological characteristics. Archaebacteria is found in small group of single-celled organisms that mostly live in extremely hot, salty, or acidic anaerobic environments. He wanted a six-kingdom classification system, in which he separated prokaryotic organisms into two kingdoms, the Archaebacteria and Eubacteria, or true bacteria, and placing eukaryotic organisms into the Kingdoms Plantae, Animalia, Fungi, and Protista.

1998 Thomas Cavalier

Thomas Cavalier divided the animal kingdom into four sub-kingdoms. Cavalier created three new animal phyla and recognized twenty three animal phyla. Under his classification system, protozoa share the fact that they have come from organisms with mitochondria and peroxisomes, they lack collagens connective tissue, epiciliary retronemes, and two additional membranes outside their chloroplast envelope.


We use the classification system to know where to place new species of animals. The different categories help label the species and what it possibly is related to. Similar species in the same kingdom can help trace the ancestry of the species, giving more insight what the species may be like and its habits.