Modern Classification System • Kingdom, Phylum, Class, Order, Family, Genus, Species • Taxonomy – structural and physiological • Phylogeny: history of the evolution of a species or group of organisms – genetic • Evolution – genetic adaptations
Levels of Classification • 2 kingdoms: Plant and Animal Single celled organisms with BOTH plant and animal traits • 3 Kingdoms: add Protista Organisms that lack a true nucleus (bacteria and cyanobacteria) • 4 Kingdoms: add Monera
Mushrooms and moulds have different traits from plants (Robert Whittaker 1769) • 5 Kingdoms: add Fungi Difference in cell structure among Monera • 6 Kingdoms: replace Monera with Eubacteria and Archaebacteria
Adaptations • Biological characteristics of a species or subspecies • Continually changing – mutations - Mutations: alteration of the genetic code, which creates heritable traits
Natural Selection • Charles Darwin in 1859 • Definition: The natural process by which only the organisms best adapted to their environment survive and transmit their genetic characteristics in increasing numbers to succeeding generations, while those less adapted may be eliminated.