1. Chapter 15

2. 1. Abiotic Synthesis of Small Organic Molecules (SOM) 2. Polymerization of SOM to form proteins and nucleic acids 3. Packaging of molecules and polymers into « protocells » 4. Self-replication of molecules necessary for « inheritance »

3. 2. Early photosynthetic Bacteria forming Stromatoliths 1. Reducing atmosphere including water vapour, CO2, CH4, NH3, H2, H2S2, Nitrogen & its sulfids

4. Mixture of gases simulating atmospheres of early Earth Spark simulating lightning storms Condensation chamber Cold water cools chamber, causing droplets to form Water vapor Liquid containing amino acids and other organic compounds

6. Analysis of a 4.5 BY-old meteorite that landed in Australia in 1968 contains 80 types of amino acids, lipids, simple surgars and uracil

7. Membrane-enclosed vesicles form when lipids are mixed with water Adding clay increase rate of vesicle formation while organic molecules concentrate on the surface of the clay

8. RNA monomers form short RNA polymers Assembly of complementary RNA chain, may have been the first step in the replication of the original « gene »?

9. Learn.Genetics –U of Utah

15. Use the ages of rocks to identify the ages of fossils found in them Use radiometric dating Carbon-14 for young fossils (½ life of 5730 years) Potassium-40 for older fossils (½ life of 1.3 BY)

17. Plate Tectonics which caused continental drift causes allopatric speciation Mass Extinctions wiped out many species at a time which allowed survivors to thrive with less competition/predation Adaptive Radiation – usually following mass extinctions « Evo-devo » – slight genetic changes can cause drastic morphological differences b/w species

19. Species became separated as the continents drifted, then evolved separately

25. Changes in Rate and Timing Changes in Spactial Pattern New Genes and Changes in Genes Changes in Gene Regulation

26. Paedomorphosis – adults that present some juvenille characteristic of an ancestral species Example : This sexually mature Axoloti is a salamander that retained external gills instead of developing lungs in adulthood

27. Genes for prognathism are turned off early in humans, while the brain continues to develop at a faster rate after birth

28. Changes in homeotic genes (HOX genes) or in how or where they are expressed changes body form

29. Duplications of HOX genes and subsequent mutations allow for novel characteristics Two duplications of the hox gene clusters seem to have occured in during the evolution of invertebrates to vertebrates allowing for backbones, jaws and limbs.

31. Thought to be only one origin of light-sensitive cells shared among all animals with the capacity to detect light

32. A particular structure can become adapted for alternative functions Feathers were probably used for mating rituals or thermoregulation in dinosaurs, but eventually became adapted for flight

33. Evolutionary trends depend on the interaction of the organism and their current environment If the environment changes, the trend can change or even reverse For example, without grasslands, there would not be a strong selection for grazers in horse ancestors

39. Based on: Shared characteristics Molecular similarities (DNA or A.A. sequences) Parsimony (simplest explanation is ususally the best)

40. Genes that seem to have reliable rate of change over time can be used as molecular clocks