1. The Historical Development of Evolutionary Theory LIFS 691 Advanced Evolution

2. What is evolution? change in the distribution of phenotypes change in genotypic frequencies change in allelic frequences to unfold, open, or unfold (Webster’s Dictionary)

3. Mechanisms of Evolution Natural Selection (including sexual selection) Genetic Drift Mutation Gen Flow

4. Natural Selection defined as the differential survival and reproduction of heritable phenotypic variants without heritability of phenotypes, the process is merely “selection”

6. Lamarckism was alive and well in the late 19 th century. Jean-Baptiste Lamarck (1744-1829) Darwin’s theory could not overcome problems created by the theory of Blending Inheritance Only about 1/3 of biologists at the time subscribed to Darwin’s theory of Evolution by Natural Selection; many evolutionary biologists still agreed with Lamarck’s ideas.

7. Gregor Johann Mendel (1822-1884) Mendel’s garden

8. “Discovery” of Mendel’s Work Mendel’s peas Provided a theory of particulate inheritance, which seemingly overcame problems imposed by the theory of blending inheritance. Unfortunately, many traits are not controlled by a single polymorphic locus; thus, Mendel’s laws did not have immediate generality. Many still doubted natural selection was the primary mechanism of evolution.

9. The Birth of Mutation Theory Hugo de Vries (1848-1935) primroses Noted sudden origins of seemingly novel phenotypes after many generations of stability Hypothesized that biochemical changes were occurring, which became known as mutations. (Actually, these changes were the product of hybridization between species of plants, but this was unknown at the time.)

10. Beginning of NeoDarwinian Theory Sewell Wright Sir Ronald Fisher (or Bakken’s lost twin?)

11. An Alternative Synthesis Richard Goldschmidt Some approached evolution theory from an understanding of genetics and development. Goldschmidt’s ideas were made unpopular to protect selectionist theories from the threat of mutationist theories. Today, he is most remembered for the concept of a “Hopeful monster,” which was a only a very small part of his contribution to evolutionary biology.

12. “Competing” Views in Evolution Neutral Theory vs. Selectionist Theories Adaptationist vs. Anti-adaptationist Optimization vs. Quantitative Genetic Theories

13. Methods for Examining Genes Candidate Loci Electrophoresis (mid-1960’s) Sequencing (mid-1970’s) Genomics (mid-1990’s)

14. “In ‘nothing in biology makes sense except in the light of evolution’, nothing in evolution makes sense except in the light of population genetics.” Richard Lewontin, Harvard University “The science of population genetics is the auto mechanics of evolutionary biology.” Rama S. Singh, McMaster University Singh (2003), Genome 46: 938-942

15. Hardy-Weinberg Equilibrium No selection Infinite population size Random mating No mutation Simple genetic system (one locus, two alleles) Non-overlapping generations Assumptions: Hardy (1908), Science

16. Hardy-Weinberg Equilibrium p = frequency of allele A q = (1-p) = frequency of allele a At equilibrium the frequencies of genotypes is as follows: AA Aaaa p 2 2p(1-p) (1-p) 2 Hardy (1908), Science