darwinian evolution i.introduction ii.influences on young darwin iii.definition of evolution...

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