THE HISTORY OF LIFE Biological Evolution UNIFORMITARIANISM Hutton
THE HISTORY OF LIFE Biological Evolution
UNIFORMITARIANISM § Hutton and Lyell § believes “the present is the key to the past” § assumes that the natural processes governing the earth today operated at the same rate throughout history
UNIFORMITARIANISM § problems • catastrophes • creation with apparent age
JEAN LAMARCK § theory of need § theory of use and disuse § theory of inheritance of acquired characteristics § basic problem: passing on acquired characteristics to future generations
CHARLES DARWIN § On the Origin of Species by Means of Natural Selection (1859)
DARWIN’S THEORY § descent with modification common ancestor § theory of natural selection • artificial selection • natural selection § survival of the fittest
DARWIN’S THEORY § problems • Natural selection regroups existing characteristics. • No new genetic information is created.
CHARLES DARWIN § On the Origin of Species by Means of Natural Selection (1859) § The Descent of Man (1871)
GEOLOGIC COLUMN the sequence of fossil-containing rock layers that shows the supposed rate of evolution
DATING METHODS § also use the principles of uniformitarianism § radiometric dating methods measure the decay of a radioactive substance into a nonradioactive substance
HUGO DE VRIES § Species and Varieties: Their Origin by Mutation § used the term “mutations”
NEO-DARWINISM § mutation-selection theory § blends Darwin’s theory of natural selection and de Vries’s theory of mutations
MUTATIONS & EVOLUTION § Mutations are random. § Mutations must occur in reproductive cells. § Evolution requires “good mutations. ” • happening repeatedly • in many, many organisms
MUTATIONS & EVOLUTION § Too many mutations will kill an organism. genetic load
PUNCTUATED EQUILIBRIUM During some periods of time, evolution occurred rapidly, while at other times, very little evolution took place.
HOMOLOGOUS STRUCTURES organs that are similar in structure and function in two different organisms
CONVERGENT EVOLUTION evolution of a similar structure in unrelated species
VESTIGIAL STRUCTURES organs which no longer have any function
- Slides: 19