Chap 22

Evolution

Cuvier tried to explain the fossil record by using the idea of Catastrophism.

Cuvier – Catastrophism

Catastrophies explain the different layers of fossils

Cuvier – Catastrophism

Catastrophies explain the different layers of fossils

Hutton- Gradualism

Geological processes take thousands of years

Hutton- Gradualism

Geological processes take thousands of years

Lyell-

Uniformitarianism- geologic processes work the same now as in the past

1. Earth is very old

2. Slow change can result in substantial change over time

Lyell-

Uniformitarianism- geologic processes work the same now as in the past

1. Earth is very old

2. Slow change can result in substantial change over time

Evolutionary Theory

Theory of Use and Disuse

Theory of Acquired Characteristics

Evolutionary Theory

Theory of Use and Disuse

Theory of Acquired Characteristics

5 Parts to Darwin’s Theory of Evolution

• There is always variation in the population• There is always a struggle for existence• Some characteristics allow for some

individuals to survive and reproduce better than others

• These characteristics are heritable• It takes many generations for change to

occur

Food Supply

Arithmetic

Food Supply

Arithmetic

Populations

Geometric Inc

Logrithmic

Exponential

Populations

Geometric Inc

Logrithmic

Exponential

Thomas MalthusThomas Malthus

(Transitional Species: fossils show change over time)

Homologous Structures: Comparable structures that have taken on different functions as a result of modification from a common ancestors

(Artificial Selection of domestic species)

8. Vestigial OrgansDegenerated organs that have lost all or most of its original function

9. Adaptive RadiationRapid adaptation of one ancestral organism to a wide range of environments leads to the formation of many new species

Changes in environment can affect survival and change overall the population’s characteristics.

Transitional Species

Descent with modification

Descent with modification

Homologous Structures

Vestigial Organ

Biogeography is the science which deals with geographic patterns of species distribution and the processes that result in such patterns

Present

Darwin expected the plants on the Galapagos to resemble those found in Europe, why was this not so?

Adaptive Radiation in Hawaiian Honeycreepers

Lines of Evidence for Evolution

• Domesticated Species/ Artificial Selection• Transitional Species/ Fossil record• Homologous structures• Vestigial structures• Embryological Structures• Biogeographical evidence• Biochemical evidence

- DNA, Protein, Amino Acid Sequencing• Adaptive radiation

Unrelated organisms adapt to similar environmental conditions