History of Evolution (W1-L1)

Early Philosophers theorized that each form has a “perfect essence” and variation is due to imperfection (not a theory on evolution)

States that species are unchaining and the role of science was to understand God’s plan. Believed by Carl Linneas.

Concept developed in Geology in the 1700s, replacing Catastrophism (geology is shaped by violent/sudden events). Theorizes that processes that observation of the past are due to present mechanisms. In evolution, indicates that evolution occurred in the past and is occurring today

Believed that individuals evolve and then pass traits to offspring aka inheritance of acquired characteristics. Known as Transformationism

Political Economist that theorized that as our standard of living increases, our population increases, therefore no amount of improved standards will eliminate the working class. Summary: there will always be human suffering. Darwin read and thought that the same concept applies to evolution: there will always be competition and favorable traits will always be preserved while unfavorable ones will be eliminated

Wrote “Principals of Geology” and introduced the idea of uniformitarianism: the earth was shaped by the same natural processes still in operation today, operating at similar intensities. Charles Darwin read his book on the H.M.S. Beagle -> applied concept to evolution

developed similar theory of evolution to Darwin while in Indonesia, shared information with Darwin, given some credit. Wrote book “Darwinism”

• All species descend from a common ancestor • species are mutable • variation exists in nature • there is a struggle for existence • some variants survive/reproduce better than others • natural and sexual selection determine which variants survive/reproduce • over immeasurable geologic time, species have changed, arisen, and gone extinct

• Absence of transitional forms (ex. fossil record) • Organisms of extreme perfection (ex. seem too complicated for evolution) • evolution of instinct (how do we justify animal behavoir) • Hybrid sterility and infertility of hybrids ( why were agricultural hybrids “better” but animal hybrids “dysfunctional”

The combination of evolutionary theory with genetics Natural selection works with variation observed in populations and according to Mendelian inheritance Theorized in the 1930s by geneticists

Change in allele frequency over time: (decent with modification)

Properties of organisms that enable them to survive and reproduce in their environment