Classification

Development of Binomial Nomenclature

• Theophrastus first attempted to organize and classify plants in the 4th century B.C.– Classified nearly

500 plants on the basis of leaf characteristics.

Development of Binomial Nomenclature

• Binomial System of Nomenclature

• First proposed by Linnaeus

• Organisms named by a phrase

• Abbreviated the phrase to 2 parts plus the person who named the organism

• Example is Spearmint: Mentha spicata L.

Classification of Major Groups• Genera are now grouped into Families.

– Families are grouped into Orders.• Orders are grouped into Classes.

– Classes are grouped into Phyla.

» Phyla are grouped into Kingdoms.

Cladistics• Cladistics is a method of examining natural relationships

among organisms, based on shared features.

chloroplasts

seeds

flowers

Vascular tissue

Relationships Between Green Plants

GreenAlgae

Ferns Pines FloweringPlants

The more characters organisms share, the more similar their DNA

Development of the Kingdom Concept

• Early classification schemes naturally classified all living organisms as either plants or animals.– The distinction works well for complex animals, but

not for simpler organisms.

Development of the Kingdom Concept

• Hogg and Haeckel 1860’s - Protista• Copeland 1938 – Monera• Whittaker 1969 – Fungi• Woese 1990’s – Archaea and Eubacteria

Table 16.01b

Should the Kingdom Concept be replaced?

• The concept of the Domain has been proposed as an alternative

Should the Kingdom Concept be replaced?

• Eukaryotic organisms form one domain

• Prokaryotic organism are divided into two other domains