Evolution/ Natural Selection/ Decent with Modification

1. Evolution/Natural Selection/Decent with Modification Chapters 14, 15, 16

2. Evolution Survey • Evolution survey.notebook

3. Key Players • Jean Baptiste Lamarck (1809) – • Charles Darwin (1859 – published) • Charles Lyell • Thomas Malthus • Alfred Wallace • WHO ELSE?

4. Project • Develop a timeline showing the Key players/events in either Pre-Darwinian or Modern Evolution/Natural Selection • Create a minimum of a 20 date timeline with images and explanations for each date • www.timetoast.com • Post to my wiki: biology-tidrick@wikispaces.com • Due Wednesay 1/18/12 by 11:59pm

5. Darwin • Darwin Timeline

6. Darwin’s Theory of Natural Selection • Two main points • Descent with modification • Traits are passed on to the next generation with slight differences • Natural selection (mechanism of evolution) • Those with the best traits to survive in the environment pass them on to the next generation • Leads to: ADAPTATIONS – characteristics that improve an organisms chance for survival/reproduction in that environment

9. Darwin’s Main Ideas • Overproduction • More organisms produced than can survive • Competition • Struggle with-in their species and other species to survive • Variation • Not every individual with in a species has the same traits • Speciation • New species arise only when organisms with new, desired traits remain

10. Darwin’s Main Ideas

11. Artificial Selection • Breeding domestic animals and plants • Select a trait • Higher chance offspring will exhibit that trait • Force a change in a faster period than nature

12. Pesticides & Natural Selection • Modeling the spread of Pesticide in a natural population • Online Activity 14.3

13. Pesticides • Why do some insects survive the initial pesticide spray? • When the surviving insects reproduce, will their offspring inherit the protective traits? • As pesticide continues to be applied, what happens to the percentage of pesticide-resistant individuals in each new generation?

14. Natural Selection and Health Science • Read Section 14.5 • Why is natural selection important in health science? • Use Sickle Cell disease and Antibiotic resistance • Answer questions on page 319

15. Evolution • Change over time • Geological evolution – changes that occur on the EARTH • Charles Lyell • Continental Drift – movement of the Earth’s Plates (~2cm/yr) • Pangea(250 mya) – supercontinent: one large land mass • Pangea breaks up (180ya) – • Evidence: Fossils (similar on coast of S.A. and Africa) • Impact on organisms: Developed separately = different adaptations • Organic Evolution • Change within a population of organisms

17. Evidence • Fossils • Geographical Distribution • Comparative Anatomy • Embryology • Molecular Biology

18. Fossils • Amber • Ice • Petrification • Molds • Cast • Imprint

19. Sedimentary Rock • Most fossils found • Fossil Record: chronological collection of life’s remains

21. Relative Dating • Compared based on layer order • Correlation – matching rock layers from one area to another • Index Files – compare to fossils all over the world (a key)

24. Four outcrops of rock are examined in different locations of a state. The rock types and the fossils they contain are illustrated in the adjacent diagram. Which fossil would be the best choice to use as an index fossil for these rocks?

25. Absolute Dating • Determines an actual time frame (#) • Radiometric Dating (radioactive dating) • Radioactive isotopes – elements that do not have a stable nucleus, when they break down they release radiation • Half-life: time required forHALF the atoms of an element to decay to a stable form

27. Geological Time Scale • Organizes Earth’s History based on major events • Eras -> Periods  Epochs  Ages • Long periods of relative stability • Brief episode of great species loss (mass extinction) • Followed by adaptive radiation - surviving organisms become wide spread and more diverse due to new habitats • http://www.enchantedlearning.com/subjects/Geologictime.html

28. Early Earth • Stanely Miller (1953) • Simulated Early Earth – produced organic molecules • Coacervate • Large protein-like substances (pre-cells) • More complex than what has been made in the laboratory • Small organic molecules  formed larger organic molecules • Able to reproduce • Pre-cells (have membranes)

30. Stromatolites • Sediment, Bacteria/Algae, mucus

31. Early Earth • Oparin – Heterotroph Hypothesis • Firstlife-like structures were heterotrophs • consumed organic molecules in water around them • no oxygen = anaerobic • Archae(extremophiles): Prokaryotes- survive in extreme environmental conditions (bacteria-like) • cellular respiration produced oxygen; over time changed the atmosphere

32. Geographical Distribution • similarities and differences between organisms in different parts of the world • geographic isolation – separation of a population due to geographic change • Why does geographic isolation not have as great an impact on species such as birds, large mammals (cyotes)? • migration

33. “Splinter” populations • Crucial events in the origin of new species • Why? • shift in the gene frequency = changing the gene pool = no longer able to reproduce with original population • Bottleneck Effect – Random decrease of population, decreases genetic diversity • Founder Effect – new colony started by a small population

34. Comparative Anatomy • the study of similarities and differences among living things • homologous structures - parts of different organisms that have similar structures, but different functions • ex: human hand, whale fin, bird wing • - evolution is a remodeling process: structure become modified and take on new functions • “Descent with modification”

35. Comparative Anatomy • Analogous structures – part of different organism that have different structures, but similar functions • ex: bird wing and butterfly wing

36. Comparative Anatomy • Vestigial structures – remnants of body parts that were functional in an ancestral form • usually reduced in size and have little or no function • genes for the smaller size would be favored • over 100 vestigial structures in humans • ex: useless – whale hip bones, eye stalks in blind crayfish, embryonic teeth in baleen whales (reabsorb), genes – humans defective gene to make vitamin C (most animals can make) • diminished use – appendix (horse cecum – digest plants; may help with immunity), wisdom teeth, coccyx (tail bone), ear muscles

37. Developmental Similarities • Embryology- studying the development from fertilized egg to fully formed organism • Embryological similarities - embryos of closely related species show similar patterns of development • All mammals develop pouches on the side of their necks (gill slits) – fish/frogs = gill slits, • structural differences become clear as development progresses

39. Homeotic genes control the placement and development of limbs, wings, antennae; a mutation will have a major impact (pg. 333) • - Minor changes in genes have subtle changes

40. Why do the tree dwelling salamanders on pg. 334 develop shorter, more webbed toes than the ground salamanders?

41. Molecular Biology • similarities/differences in the sequences of amino acids of proteins and the DNA code • more similar sequences = more closely related • new way to test structural hypothesis (whale, hippo, cow, deer, and pig DNA very closely related – supports fossils and anatomy) • common genetic code shared by all species

42. DNA AnalysisCompare segments of beta-casein gene

43. DNA AnalysisCompare segments of beta-casein gene

44. DNA Differences

45. DNA Differences

46. DNA DifferencesFewer than five differences… • 2 porpoise & sperm whale • 3 porpoise & right whale • 3 sperm whale & right whale • 3 sperm whale & hippo • 3 porpoise & hippo • 3 right whale & hippo • 3 giraffe & deer • 3 giraffe & cow • 4 cow & deer

47. DNA DifferencesSeven differences… • 7 pigs and peccaries DNA DifferencesRemaining species… Higher numbers - more distantly related

48. Phylogenetic Tree - SAMPLEBased on DNA Differences

49. Provisional Phylogeny - Cetartiodactyls