Darwinian evolution

I. IntroductionII. Influences on young DarwinIII. Definition of evolutionIV. MechanismV. Example VI. Pieces of evidence supporting theory

I. Intro to Darwinian evolution

• Unifying principle of biology

• Helps to explain how change has occurred over time

• Nothing magical about how it occurs

Influences on a young Charles Darwin

II. Influences on a young Darwin

A. Family Background

• 1. religious family• 2. professions considered• 3. naturalist

B. Voyage of the Beagle

C. Galapagos Islands

• 1. Tortoises• 2. Iguanas• 3. Finches• 4. Adaptive

radiation

D. Thomas Malthus

• 1. Economist• 2. Malthusian

Principle• 3. Introduced the

concept of struggle

E. Artificial selection

• 1. man’s selection of breeding pairs to produce desired “phenotype”

• 2. examples• 3. significance

III. Definition of evolution

• A. Slow and gradual change over time in organisms appearance in response to environmental change

• B. Organisms living today appear different than their ancestors

• C. Living organisms share common ancestors

IV. Mechanism of Change/Natural Selection

• A. Variation exists in all populations

• B. Reproductive potential

• C. Variable fitness• D. Environmental

carrying capacity• Differential reproduction• Slow gradual change in

phenotype

V. Example of evolutionary change

• Size of beagle ears

• Environment changes

• Results

VI. Evidence of evolutionary change

• A. Vestigial structures

• B. Homologous structures

Evidence cont.

• C. Common embryology

Evidence cont.

• C. Common embryology

• D. Fossil record– 1. Missing links

Evidence cont.

• C. Common embryology

• D. Fossil record– 1. Missing links– 2. Phylogenies