1. Darwin and His Theory
7/22/2019
Evolution
Nothing in biology makes sense except in the light of evolution. Theodosius Dobzhansky
Charles Darwin in later years
G. Podgorski, Biol. 1010

2. Darwin and His Theory
7/22/2019
What is Evolution?
Working definition: evolution is the progressive change in organisms over time.
G. Podgorski, Biol. 1010

3. Evolution’s Core Principles
Darwin and His Theory
7/22/2019
Evolution’s Core Principles
1. Natural selection.
Individuals who are better adapted to their environment are more likely to survive and reproduce.
G. Podgorski, Biol. 1010

4. 2. Common descent with modification.
Darwin and His Theory
7/22/2019
2. Common descent with modification.
Organisms evolve from a common ancestor, with traits gradually changing over time.
G. Podgorski, Biol. 1010

5. Darwin’s Voyage of Discovery
Darwin and His Theory
7/22/2019
Darwin’s Voyage of Discovery
G. Podgorski, Biol. 1010

6. The Voyage of the Beagle
Darwin and His Theory
7/22/2019
The Voyage of the Beagle
G. Podgorski, Biol. 1010

7. Darwin’s Observations
Darwin and His Theory
7/22/2019
Darwin’s Observations
Production of more individuals than can be supported by the environment leads to a struggle for existence. Only a few offspring survive in each generation.
G. Podgorski, Biol. 1010

8. Darwin’s Observations
Darwin and His Theory
7/22/2019
Darwin’s Observations
Individuals of a population vary extensively in their characteristics with no two individuals being exactly alike. Much of this variation between individuals is based characteristics passed on from the parents.
G. Podgorski, Biol. 1010

9. Darwin’s Observations
Darwin and His Theory
7/22/2019
Darwin’s Observations
Survival in the struggle for existence is not random, but depends in part on the heritable characteristics of individuals.
Individuals who inherit characteristics most fit for their environment are likely to leave more offspring than less fit individuals.
G. Podgorski, Biol. 1010

10. Darwin’s Observations and Inferences
Darwin and His Theory
7/22/2019
Darwin’s Observations and Inferences
Inference 3: The inability of some individuals to survive and reproduce leads to a gradual change in a population, with favorable characteristics accumulating over generations. This is natural selection.
G. Podgorski, Biol. 1010

11. The Weak Link of Genetics
Darwin and His Theory
7/22/2019
The Weak Link of Genetics
“The D Train” in
his early years.
A major problem in Darwin’s theory was the lack of a mechanism to explain natural selection.
Gregor Mendel’s work on genetics was rediscovered in the first half of the 20th century. The missing link in evolutionary theory was found.
G. Podgorski, Biol. 1010

12. Two of many arguments made against evolution are:
Darwin and His Theory
7/22/2019
Two of many arguments made against evolution are:
Evolution is only a theory.
No one’s ever seen evolution.
The first point is true, but misses the meaning of scientific theory, and the second point is easily countered.
G. Podgorski, Biol. 1010

13. Evidence for Evolution – The Fossil Record
Darwin and His Theory
Evidence for Evolution – The Fossil Record
7/22/2019
G. Podgorski, Biol. 1010

14. Evidence for Evolution - Comparative Morphology
Darwin and His Theory
7/22/2019
Evidence for Evolution - Comparative Morphology
Why use the same skeletal plan for these very different appendages?
G. Podgorski, Biol. 1010

16. Evidence for Evolution - Comparative Embryology
Darwin and His Theory
7/22/2019
Evidence for Evolution - Comparative Embryology
G. Podgorski, Biol. 1010

17. Evidence for Evolution – Biochemical Analysis
Darwin and His Theory
7/22/2019
Evidence for Evolution – Biochemical Analysis
G. Podgorski, Biol. 1010

18. Evolution of pesticide resistance in response to natural selection.
Darwin and His Theory
Evolution of pesticide resistance in response to natural selection.
7/22/2019
Evidence for Evolution
Evolution Observed
G. Podgorski, Biol. 1010