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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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