ANTH 1102 1st EditionLecture 10Outline of Last Lecture I. Race in the USII. Biological AnthropologyA. What it StudiesB. Theory of EvolutionC. Scientific TheoryD. Evolution TermsOutline of Current LectureI. EvolutionA. TheoriesB. Darwinian EvolutionII. Genetics and EvolutionIII. Biochemical GeneticsIV. Population GeneticsA. Four Forces of MicroevolutionCurrent LectureEVOLUTION- early ideas to explain fossil record (1800s)- catastrophism (Georges Cuvier): fossil record evidences divine natural disasters- transformism (Erasmus Darwin): descent with modification (one common ancestor of all living forms)- uniformitarian (Sir Charles Lyell): current earth processes are the same as those in the past (e.g. Bryce Canyon, Utah)Darwinian Evolution: Charles Darwin (and Alfred Wallace) created a theory to explain change, the origins of species, and natural selection- principles: variation exists, inheritance (variation is heritable), differential survival and reproduction-> struggle for existence- conclusion: biological change (natural selection)- those forms most successful atreproducing in specific environments are selected; no two individuals in a species are identical, and offspring resemble their parents- superior fitness: ability to reproduce successful and surviving offspring-> specific environments (environmental niches created)- adaptation: series of beneficial characteristics- Darwinian evolution does NOT claim we evolved from monkeys or use anddisuse (inheritance of acquired characteristics)- Evolution does not always mean progressive changes or require increased complexity- Natural selection works on the most “fit”; environments change and lead to species that no longer “fit”, e.g. Guam rail (birds) disappeared after the introduction of brown snakes (predators)GENETICS and EVOLUTION- Darwin’s missing keys: mechanisms of inheritance, origin of variation, and population genetics- Mendelian Genetics (Gregor Mendel)> hybridization experiments with pea plants found that heredity units=factors determined by discrete inherited particles (genes), and the organism gets one factor from each parent> principles of heredity: segregation (one factor from each parent), dominance and recession, independent assortment and recombination- Chromosome Theory of Inheritance introduced the terms: chromosomes, alleles, homozygous/heterozygous, genotype, phenotype> genetic inheritance uses Punnett Squares to determine phenotypes of offspring by multiplying factors; dominant genes are capitalized, recessive genes are lower case> e.g. trait=eye color, B=brown (dominant gene), b=blue (recessive gene); father is BB and mother is bb-> all offspring would have brown eyesb bB Bb BbB Bb Bb> e.g. B=brown, b=blue, g=green; father is Bb and mother is gg-> half offspring would have brown eyes, and other half have equal chances of green or blue eyesB bg Bg gbg Bg gb> simple/discrete traits: one gene controls, e.g. tongue rolling, attached earlobes> complex/polygenic traits: multiple genes control, e.g. skin collorBIOCHEMICAL GENETICS- Darwin nor Mendel knew where traits come from- cell division: mitosis (regular cells), meiosis (sex cells)- crossing over: during meiosis, chromosomes intertwine and exchange segmentsof DNA- mutations: random change in DNA molecules (ultimate source of all new variation); two types: chromosomal rearrangement and base substitution- inheritance in pea plants: PP: purple (dominant), pp: white (recessive)> F1 generations- hybrids, F2 generation- 3 purple, 1 white- genetic evolution: change in allele frequencies in a population over timePOPULATION GENETICS- Four Forces of Microevolution> natural selection> mutations - provide variety on which natural selection can work, e.g. Down’s and Kleinfelter’s Syndrome- point mutations (single base pair): original “S” allele of hemoglobin, original LAC-P allele-> lactose digestive capacity> random genetic drift- change in allele frequencies due to chance, increases speciation- “founder effect”: group of individuals leave one population to join another, e.g. The Dunkers, ABO blood type people similar to Amish and Quakers fledGermany to go to the