Section 18-1: Finding Order in Diversity

Need to describe and name each species to understand and study diversity

Use scientific names to ensure talking abut the same animal

Common names translate, vary Ex. Felis concolor commonly known as

cougar, puma, panther, mountain lion

18th century Europeans used Latin or Greek names to describe species based on traits

Did not work – not standardized 1730s: Swedish botanist Carolus Linnaeus

developed a two-word naming system called binomial nomenclature

Scientific name usually Latin, written in italics

First word capitalized, second lowercase

Polar bear is Ursus maritimus.

First part of the name is the genus, which is a group of similar species

Second part of unique to each species and is often a description of the organism’s habitat or of an important trait

Biologists try to organize/classify living and fossil species into larger groups that have biological meaning

Groups called taxa (singular: taxon) The science of naming and grouping

organisms is called systematics

Hierarchy Organisms grouped by anatomical

similarities and differences Linnaeus had four levels, which

expanded to seven taxa

Species, Genus, Family, Order, Class, Phylum, Kingdom

Members of a species determine which organisms belong to that species

Ranks above species are determined by researchers who decide

Linnaeus grouped organisms into larger taxa according to overall similarities and differences

Example: adult barnacles and limpets live attached to rocks, have similar-looking shells

Adult crabs don’t look anything like them, and would probably be in a different group

Wrong! Modern classification schemes look beyond

overall similarities and differences and group organisms based on evolutionary relationships