Living things are classified into a hierarchy with seven main levels: kingdom, phylum, class, order, family, genus, and species. Aristotle originally classified living things as either plants or animals, while Linnaeus later classified them based on their structure. Modern classification, like Linnaeus', is based on phylogeny, or the evolutionary history of organisms.

1. How are Living Things Classified?

2. History of Classification 2,000 years ago, Aristotle classified living things as either plants or animals. 400 years ago, Linnaeus, classified livings things based on their structure. Modern classification is much like Linnaeus’. Based on Phylogeny : the evolutionary history of an organism.

3. Classification Kingdom Phylum Class Order Family Genus Species