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Controversy over Evolution: Why is it a Hot Topic?

This article explores the controversy surrounding the topic of evolution, discussing the importance of variation within species and how adaptation helps organisms survive. It also examines the contributions of scientists like Cuvier, Malthus, Lyell, Lamarck, Wallace, and Darwin. Additionally, it presents evidence supporting the modern theory of evolution, including biogeography, comparative anatomy, comparative embryology, comparative biochemistry/molecular biology, DNA sequencing, and the fossil record.

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Controversy over Evolution: Why is it a Hot Topic?

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  1. UNIT IV: EVOLUTION, CHANGE AND DIVERSITY

  2. Why is the topic of evolution so controversial? https://answersingenesis.org/theory-of-evolution/in-schools/ https://www.youtube.com/watch?v=UdXHktAAOcc

  3. Modern Day EvolutionIndustrial Melanism- The Peppered Moth • An example of evolution • It highlights the importance of variation within a species and how this adaptation can help them survive. Peppered Moth Stimulation http://www.techapps.net/interactives/pepperMoths.swf

  4. Page 2 in Booklet

  5. Adaptation- an inheritable characteristic that helps an organism survive and reproduce in an environment.

  6. Variation- the differences in characteristics of a species.

  7. Natural Selection Artificial Selection A process where a breeder decides what traits will be passed on Ex: Dog breeding • A process where individuals with favorable traits survive to pass on their traits to their offspring • Ex: Peppered Moth

  8. Contributions of ScientistsPage 3 in Booklet Georges Cuvier • Developed the science of paleontology (fossils) • He believed catastrophism caused new species

  9. Thomas Malthus • He proposed the theory of population growth • There is not enough food to feed the growing world population

  10. Charles Lyell • Evolution is slow and gradual • He believed in Uniformitarianism

  11. Jean Baptiste Lamarck 1. Law of use or disuse 2. The Law of Inheritance of Acquired Characteristics

  12. 1. The Law of Use or Disuse • Use it or lose it If an organism uses a trait it remains active and strong, but if not used then it becomes weak and disappears.

  13. The Law of Inheritance of Acquired Characteristics • Favorable traits can be passed on to the next generation. • Since giraffes stretched their necks during their lifetime then this trait was passed onto their offspring.

  14. Modern Day example that disproves the theory of "inheritance of acquired characteristics": Chinese women bound the feet of their infant children for several thousand years, yet the feet of Chinese women today are normal in size.

  15. Alfred Russell Wallace • Forced Darwin to publish his book, he was working on a similar theory

  16. Charles Darwin Developed the theory of Natural Selection (survival of the fittest) Don’t write: His came up with his theory after consulting several different sources: A. Maltus’ Essay B. Selective (Artificial) Breeding C. Lyell’s Book D. Darwin’s Personal Observations https://www.youtube.com/watch?v=6GNUlZhE_jE

  17. Page 4 booklet Explain how the finches evolved on the Galapagos Island. 1st – variation within the species (ex: beak shape) 2nd – those with the “best” adaptations were more fit (ex: large beak to crush seeds) 3rd – they survived in the environment 4th - passed on their traits to offspring

  18. Page 4 booklet Why is the medical community concerned about the overuse of antibiotics? • People often don’t take all their antibiotics • As a result, all the bacteria are not killed • The strongest bacteria is left to reproduce and pass on their traits to the offspring, making extra strong bacteria that are resistant to antibiotics

  19. Finish pages 4 and 5 in Booklet for homework These are practice questions

  20. Support for the modern theory of evolution • Scientific evidence we use to support the theory of evolution

  21. 1. Biogeography • The study of the geographic distribution of a species. Video: Island of Lemurs https://www.youtube.com/watch?v=Q_7cVyM8Efg&safe=active

  22. 2. Comparative Anatomy a. Homologous structures –Anatomy is similar in shape, structure and origin.

  23. b. Analogous structures similar structures but are anatomically different. This is evidence to suggest theses organisms did not evolve from a common ancestor.

  24. c. Vestigial organs - structures that have lost their function, but were functional in an ancestor of the organism.

  25. Video: Evolution of Whales http://ocean.si.edu/ocean-videos/evolution-whales-animation

  26. 3. Comparative Embryology • Compare the structures of the embryos Similar structure is evidence for close evolutionary relationship

  27. 4. Comparative Biochemistry/ Molecular Biology • Scientists compare the chemical composition (DNA) of different organisms. Examples: Hemoglobin of monkey’s is similar to the hemoglobin of man. The insulin from a pig or cow can be used to treat diabetes in humans.

  28. 5. DNA sequencing • Compare the sequence (order) of DNA Example: • Humans and chimpanzees have 2.5% difference in their DNA sequence • Humans and lemurs have 42% difference • Therefore humans are more like chimpanzees than lemurs

  29. 6. Fossil Record a. Relative Dating - an estimate of the age of a fossil by its location in sedimentary layers (oldest on bottom) • Scientists have discovered that it takes approximately 1000 years of sediment to produce 30 cm of sedimentary rock. Example: 150cm deep means a relative age of 5000 years.

  30. Absolute Dating - an exact age of a fossil done by radioactive dating Living organisms accumulate certain radioactive isotopes when they are living. Once these organisms die, the radioactive isotopes start to breakdown. The rate of this breakdown is called half life. The greater the amount of decay product the older the fossil.

  31. How to do a half life problem

  32. Half-Life Problems(page 8 in notes) • Carbon 14 has a half life of 5730 years. How long will it take for carbon 14 to decay to 1/8 of its original amount?

  33. Examples include some of the isotope pairs found in the following table:

  34. Half Life ProblemsPage 7 in Booklet 1. Carbon 14 has a half life of 5730 years. How long will it take for C14 to decay to 1/16 of its original amount?

  35. 2. Uranium has a half life of 700 x 106 years. How long will it take for uranium to decay to ¼ of its original amount?

  36. 3. The half-life of carbon-14 is 5730 years. How old is a fossil that contains 6.25 % of the original carbon-14?

  37. 4. If the half-life of carbon is 5730 years, what percent of carbon would be contained in a rock sample that is 22 920 years old?

  38. Finish pages 8 and 9 in Booklet for homework These are practice questions

  39. Hardy-WeinburgEquilibriumPage 10 in Booklet • Used to determine whether or not evolution is occurring in a population. • The law states that under certain conditions, allele frequencies will remain constant (genetic equilibrium) in a gene pool and there will be no evolution. http://www.youtube.com/watch?v=JsuJlewaPX0&safe=active

  40. Five Conditions • The population must be large. (No genetic drift) • Individuals must not migrate into or out of the population • Mutations must not occur • Reproduction must be completely at random. • No genotype is more likely to survive and have offspring than any other genotype.

  41. Allele frequency p + q = 1 p is the dominant allele frequency q is the recessive allele frequency

  42. Genotype frequency p2 + 2pq + q2 = 1 p2 homozygousdominant frequency (TT) 2pq heterozygousdominant frequency (Tt) q2 homozygousdominant frequency (tt)

  43. Practice Public Exam Question 1. A teacher observed that the frequency of students able to roll their tongue has decreased over thirty years. Is this population in Hardy-Weinberg Equilibrium? Give three reasons to support your answer.

  44. Answer:

  45. How can you tell evolution is occurring? If the allele frequency in a population changes, then the Hardy-Weinberg Law fails and it is therefore a sign that evolution is occurring.

  46. Page 11 in Booklet 2 (a) in 30 pea plants, they have 60 alleles present for height (each plant has 2 alleles). A survey tells you that the frequency of the T allele 0.6 (60%) and the frequency of the t allele is 0.4 (40%). You can use the Hardy-Weinberg formula to calculate the genotypic frequencies of the population.

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