Evolution Review

1. Evolution Review 2013

2. History of Major Events • Earth is 6 billion years old • Radiometric Dating: a method to establish the age of materials. Radioactive decay = half life • First organic compounds • Urey Miller experiment were able to produce organic compounds by initiating lightening on water vapor, H2, CH4 and NH3 • Development of first cells– Microsphere and coacervates.

3. Transition of chemosynthetic, photosynthetic, and aerobic • Chemosynthetic used sulfur for energy– Archaea today • Gave rise to photosynthetic bacteria –used sun as energy source---aerobic respiration produces O2 • Eukaryotic organisms developed through endosymbiosis—chloroplasts and mitochondria • Check events that lead to aerobic life. Why did heterotrophs evolve first?

4. Modern Evolutionary Theory • People: Explain their contribution on Darwin’s thinking • Darwin • Cuvier • Lyell • Lamark • Wallace • Malthus • Steno

5. Darwin • Traveled to Galapagos • Studied how animals adapted to environments • Ship: HMS Beagle • Book: On the Origin of Species by means of Natural Selection • Did Darwin know anything about genetics?

6. Evidence for evolution • Fossils • Species variation • Anatomy/embryology • This is very incomplete!!!!!! Check your book and the ppt. on Charles Darwin.

7. Species and populations • Microevolution: change in the collective genetic material of a population • Put in some examples here • Macroevolution: the evolution of a species on a large scale. Effects the entire species • Give examples

8. Hardy-Weinberg • Genotype frequencies in a population tend to remain the same from generation to generation unless acted o by outside influences. • Conditions for a stable population • No mutation • No immigration or emigration • Pop. Is large • Selection does not occur • Individual mate randomly

9. Causes of microevolution • Mutation; give example • Gene flow: give example • Genetic Drift: give example • Nonrandom mating: give example • Natural Selection: give example

10. Variation in a population • Sources: • Mutation: random change in a gene passed to offspring • Recombination: reshuffling of genes during independent assortment and crossing over. • Random pairing of gametes: large number and fetilizes randomly.

11. Single gene traits: determined by a single gene with two or more alleles Examples • Polygenic traits: influenced by several genes. Examples • Patterns of Natural Selection • Disruptive • Stabilizing • Directional • Be able to draw each type and explain what is happening.

12. Steps in speciation • A species is a pop. of organisms that can successfully interbreed but cannot breed with other groups. • Geographic isolation results from the separation of population subgroups by geographic barriers. • Geographic isolation may lead to allopatric speciation.

13. Allopatric speciation: two groups become separated geographically which results in reproductive isolation because of • Genetic drift, • Mutations • Natural selection

14. Reproductive isolation: results from the separation of population subgroups by barriers to successful breeding. • Reproductive isolation leads to sympatric speciation.

15. Sympatric speciation: two population become reproductively isolated within the same geographic area. • Each species occupies a different niche • This specialization leads to reproductive isolation.

16. Rates of Speciation • Gradualism: species undergo small changes at a constant rate. • Punctuated : new species arise abruptly, differ greatly from their ancestors, and then change little over long periods.