Intro to Evolution

Introduction to Evolution

Huxley pointed out the huge gap between homosapiens and beasts didn't always exist. Gap took place over evolutionary period, with powerful adaptations for apes.

Evolution is often related to climate and environment, history would be different if conditions changed.

Evolution works though:

 Mutation: producing of a genetic variation, which drifts (varies among the population)

 Gene Flow: introduction of new genes from other populations

 Natural Selection: differential reproduction of those with adaptive traits produce more offspring

These processes form new organisms by:

 Populations evolving in a linear manner, as small changes in one generation to another improve adaptation. This accumulates over time and an older species may from into a new one.

 Evolution proceeding in a branching manner, in response to isolating mechanisms. This leads to divergent races then divergent species

Charles Darwin 1809-1892

 Study of medicine in Edinburgh, not suited for some went to Christ's College, Cambridge and studied theology

 Took position of naturalists

 mapping on HMS Beagle in 1831

 Mapping along S. America, Galapagos Islands, Australia and back to England

On the Origin of Species (1859)

 Observed each island had its own for of tortoise, mockingbird and finch; all with close relations to one another

 Darwin was not inventor of evolution

 Jean Baptiste de Lamarck, a philosopher and naturalist proposed evolution in 1809

 Darwin was intrigued by the problem of origin and diversity and diversification in geographical dimension Ð'- in horizontal evolution

 In 1838 he conceived the mechanism that could account for evolution: natural selection

 His full theory of evolution was published on November 28, 1859 in The Origin of Species

In his book, Darwin proposed his broad explanatory scheme comprised a number of component sub theories or postulates. The four (4) main postulates were:

1. The world is not static but evolving: species change continuously, new ones originate and others become extinct.

2. The process of evolution is