Darwinism

The Origin of the Species by Natural Selection

Plato

Believed there were two worldsA real world that is ideal and eternal

An illusory world of imperfection perceived by senses

Aristotle

Believed that all living forms could be arranged on a scale of increasing complexity. This was known as scala naturae.

Charles DarwinSon of a prominent physician in EnglandAt age 16 his father sent him to the University of Edinburgh to study medicineEnrolled at Christ College at Cambridge to become a clergymanIn December of 1831 at the age of 22 he sailed with the crew of the HMS Beagle1844 – Wrote a long essay on the origin of species by natural selection1859 – Published The Origin of the Species by Natural Selection

Others Influencing Darwin

Linnaeus George

Cuvier

James

Hutton

LyellJean

Bapiste

Lamark

Wallace

Summary of Darwin’s Ideas

Natural Selection is the differential success in reproduction, and its product is adaptation of organisms to their environmentNatural selection occurs from the interaction between environment and the inherent variability in a population

Variations in a population arise by chance but natural selection is not a chance phenomenon, since environmental factors set definite criteria for reproductive success.

Variation and overproduction make natural selection possible

Examples of Natural Selection in Action

Average beak depth varies with rainfall

Butterfly population adapted to a vegetation change in a ten year period

Antibiotic resistant bacteria

The Evidences for Evolution

Artificial Selection Fossil Evidence Comparative Anatomy

Embryology Comparative Biochemistry Biogeography

Figure 22.2 Fossils of trilobites, animals that lived in the seas hundreds of millions of years ago