5.4: An introduction to the Theory of Evolution

1. 5.4: An introduction to the Theory of Evolution

2. What do we need to know about Evolution (Weds)? • 5.4.1: Define Evolution • 5.4.2 Outline the evidence for evolution (X4) • 5.4.3: State that populations tend to produce more offspring than the environment can support • 5.4.4. Explain that one of the consequences of potential ovrpopulation is a struggle for survival

3. What do we need to know about Evolution (Thurs)? • 5.4.5. State that the members of a species show variation • 5.4.6. State how sexual reproduction promotes variation in a species • Explain HOW natural selection leads to evolution • Explain two example o evolution in response to environmental change

4. Objectives for today • Meet Charles Darwin and his world-changing ‘theory’….

5. 5.4.1: Define Evolution 5.4.2: Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures ‘Isn’t Evolution “just” a theory?’

6. Darwin’s Theory of Evolution • "the single best idea anybody ever had” (Daniel Dennet, Philosopher) • “a big idea, arguably the most powerful idea ever “ (Richard Dawkins, Philosopher) • “Its publication (The Origin if Species) changed the world”

7. 5.4.1: Define Evolution

8. Synonyms for Evolution • Charles Darwin used ‘Descent with modification’ • ‘Survival of the fittest’ • ‘Theory of Natural selection’

9. Richard Dawkins’ Theory of Evolution ‘Given sufficient time, the non –random survival of hereditary entities (which will occasionally miscopy) will generate complexity, diversity, beauty and an illusion of design so persuasive that it is almost impossible to distinguish from deliberate intelligent design’

10. Hypothesis vs. Theory • What’s the difference?..... • http://www.youtube.com/watch?v=85diEXbJBIk&feature=youtu.be (6 minutes)

11. Let’s begin by meeting Charles Darwin… • http://www.youtube.com/watch?v=vmphlbRhLu8&feature=youtu.be (6.40 mins)

12. Evolution in a nutshell: The Tree of Life • Wellcome Tree of Life • http://www.wellcometreeoflife.org/

13. Homework:

14. Charles Darwin • Now that you have background on Charles Darwin read the short packet and answer the questions. • Natural Selection: The survival and reproduction of individuals with favorable heritable traits. • Empirical Evidence: the record of one's direct observations or experiences

15. Friday 1. The Evidence for Evolution 2. How does natural selection actually work? • Examples of natural selection in action: antibiotic resistance, rodenticide resistance, pesticide resistance…

16. Opponents to The Theory of Evolution: The Blind Watchmaker oh yeah, it's David Attenborough again...

17. Evidence for Evolution • 1. The Fossil Record • 2. Artifical Selection – breeding of plants and domestic animals • 3. Geographical Distribution • 4. Homologous Structures

18. Evidence for Evolution 1: The Fossil Record

19. The Fossil Record • Palaeontologists uncover fossilised remains in sedimentary rock deposits and use the information to create timelines • Organic matter trapped in sand/ silt/fossils • Compressed over time • Dated by isotopic carbon (50,000 years), potassium40 (1.28 Billion years), 238 Uranium • Oldest fossils are at the bottom, youngest at the top

20. Other methods for dating fossils • Dating Methods

21. Fossil Evidence for Evolution http://www.pbs.org/wgbh/evolution/sex/mating/index.html

22. Evidence for Evolution 2: Homologous structures • Homologous traits have similar embryological origins and development • Indicative of common acnestry: what Darwin called ‘Unity of Type’ • Indicative of adaptive radiation • Pentadactyl limb • Human appendix • Whale pelvic and thigh bone

23. Homologous structures: Pentadactyl Limb

24. Homologous structures: Whale Pelvic bone

25. Homologous structures: Human appendix

26. Evidence for evolution 3: Artificial Selection

27. Evidence for evolution: Artificial selection

28. Evidence for evolution: Geographical Distribution • Before humans arrived, Australia had > 100 types of marsupials, but no placental mammals • Hawai’I and New Zealand had unique biotic environments – plants, insects, birds but no placental mammals

29. Evidence for Evolution: Observable Changes • Development of new species is RAPID in species with a short reproductive cycle: bacteria, viruses, parasites, moths etc etc etc

30. Week 5: October 2 - 5 • TEST on populations and evolution: Friday or Monday?

31. The Mechanism of Evolution: Natural Selection

32. Hummingbirds and natural Selection

33. How does natural selection work? • Too many offspring • Natural genetic variation • Struggle for survival • Differential survival and reproduction

34. Too many offspring • Results in competition for available resources – food, shelter, mates, water, sunlight

35. Natural Variation: Prokaryotes • Bacteria and other primitive organisms reproduce asexually • May change their genetic make-up by means of mutation • May change their genetic makeup by means of plasmid transfer

36. Natural Variation: Eukaryotes Mutation • Mutations can result in advantageous or disadvantageous changes • In each generation, only a few genes mutate, and most mutations produce effects that are neither good or harmful Sexual Reproduction A much more powerful source of combination, since thousands of genes are mixed and copied • MEIOSIS • CROSSING OVER in prophase 1 • Random assortment of chromosomes in metaphase 1 • RANDOM FERTILISATION

37. http://i-biology.net/ibdpbio/05-ecology-and-evolution/evolution/http://i-biology.net/ibdpbio/05-ecology-and-evolution/evolution/ • Slide 14 – 27 • http://www.pbs.org/wgbh/evolution/library/01/2/quicktime/l_012_02.html

38. Peppered Moth simulation • Peppered moth simulation

39. Your evolution Assignments: for Thursday • On the syllabus for 5.4.8, it says "Explain two examples of evolution in response to environmental change; one must be antibiotic resistance in  bacteria. “ • Your job is to find information on another example of evolution in response to environmental change.  You should be prepared to share with the class a brief summary that includes: what organism was affected, what caused the change, and what the change was.  • !

40. Group 1: Antibiotic Resistance in Bacteria Group 1 will look at develop of antibiotic resistance against tuberculosis Resources: • http://www.sumanasinc.com/scienceinfocus/sif_antibiotics.html • http://www.who.int/topics/tuberculosis/en/ • http://www.euro.who.int/en/what-we-do/health-topics/communicable-diseases/tuberculosis • http://www.guardian.co.uk/world/2012/mar/25/drug-resistant-strains-of-tb • http://www.cdc.gov/tb/

41. Group 2: Pesticide Resistance Group 2 will look at development of pesticide resistance in rodents Resources: • http://www.mhhe.com/biosci/esp/2001_gbio/folder_structure/ev/m2/s1/evm2s1_6.htm • http://www.pbs.org/wgbh/evolution/library/10/1/l_101_02.html • http://evolution.berkeley.edu/evolibrary/article/agriculture_04

42. Group 3: Development of resistance in Malaria parasites Group 3 will look at development of drug resistance in Malaria parasites (and also look at evolutionary strategies being used to combat malaria!) • http://www.bbc.co.uk/news/health-17628172 • http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)60484-X/abstract • http://online.wsj.com/article/SB10001424052702303815404577335703043691304.html • http://www.who.int/drugresistance/malaria/en/ • http://www.who.int/drugresistance/publications/WHO_CDS_CSR_DRS_2001_4/en/index.html • http://www.scientificamerican.com/article.cfm?id=malaria-resistant-mosquitoes-lab-bred-first-time

43. Group 4: Peppered Moths Group 4 will look at the evolution of the peppered moth in industrial UK (industrial melanism, quite controversial!) • http://www.techapps.net/interactives/pepperMoths.swf • http://www.christs.cam.ac.uk/darwin200/pages/index.php?page_id=g5 • http://www.youtube.com/watch?v=LyRA807djLc • http://www.bbc.co.uk/radio4/science/thematerialworld_20071011.shtml