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What’s Left in LB145? Last Class: Course Evaluations Take up Exam Begin Evolution Unit Today: PowerPoint Presentation
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What’s Left in LB145? Last Class: Course Evaluations Take up Exam Begin Evolution Unit Today:

What’s Left in LB145? Last Class: Course Evaluations Take up Exam Begin Evolution Unit Today:

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What’s Left in LB145? Last Class: Course Evaluations Take up Exam Begin Evolution Unit Today:

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  1. What’s Left in LB145? Last Class: • Course Evaluations • Take up Exam • Begin Evolution Unit Today: • Finish Evolution Unit Tuesday Apr 23rd: • Bonus survey • Traditional review (?) Thursday April 25th: • Question-based review(?) • Don’t Forget… • Friday April 19th: • View Exams 1, 2, 3 in C4 from 1-3pm. OR Office hours. • Weds/Thurs April 24th/25th: • Lab Projects Due. • Friday April 26th: 3-5pm in C-3 • Last-Gasp Tutorial • (email me to reserve a place)

  2. Evolution Write it Down: What is evolution?

  3. Evolution Write it Down: Why is evolution controversial?

  4. Social-Political-Religious Pressures Source: Gallop Poll 2007

  5. Why is Evolution treated differently from other theories? • Social-Political-Religious Pressures • It’s presented as belief construct • It is complicated and is not often taught/learned very well Other Academic Theories Big Bang Theory, Cell Theory, Germ Theory, Molecular Theory, the Kinetic Theory of Gasses, Molecular Orbital Theory, Variance Bond Theory, Transition State Theory, Marchs Theory, Debye-Huckel Theory, Thermodynamic Theory of Polymer Elasticity, Density Functional Theory, Baeyer Strain Theory, Climate Change Theory, Macroeconomic Theory, Microeconomic Theory, Constructivist Theory, Critical Pedagogy Theory, Multiple Intelligence Theory, Circuit Theory, Control Theory, Systems Theory, Film Theory, Theory of Plate Tectonics, Literary Theory, Approximation Theory, Coding Theory, Intersection Theory, Matrix Theory, Model Theory, Ring Theory, Music Theory, Proof Theory, Theory of Truth, Acoustic Theory, Atomic Theory, Perturbation Theory, Theory of Relativity, Theory of the Mind, Cognitive Dissonance Theory, Attachment Theory, Theory of Self Fulfilling Prophecy, Sociological Theory, Critical Theory, Extreme Value Theory, Performance Theory….

  6. Evolution Write it Down: How would you explain evolution to a non-scientist? Evolution through natural selection…

  7. Mouse Fur Color MC1R protein is stimulated and facilitates cAMP production. cAMP is used to regulate gene expression. c(tyr) Tyrp1 Tyrp2 p

  8. Evolution Evolution through natural selection…

  9. Pea Seed Taste

  10. Definitions of Evolution…

  11. Evolution – the simplest of definitions:

  12. Evolution – the simplest of definitions: Descent with modification.

  13. Descent with modification of… • Nucleotides (mutations!) • Alleles • Genes (deletion/duplication) • Proteins • Cell function • Selectable SPhenotype

  14. Evolution – a diversity definition Biological evolution is change in the properties of populations of organisms that transcend the lifetime of a single individual. Biological evolution may be slight or substantial; it embraces everything from slight changes in the proportion of different alleles within a population to the successive alterations that led from the earliest protoorganism to snails, bees, giraffes, and dandelions. Douglas J. Futuyma

  15. Evolution is… … the process by which different kinds of living organisms developed and diversified from earlier forms during the history of the earth.

  16. Patterns of Relatedness

  17. Evolution – a populations definition “Evolution can be precisely defined as any change in the frequency of alleles within a gene pool from one generation to the next” Helena Curtis and N. Sue Barnes

  18. Darwin’s Evolution • Had no knowledge of genetics. • Connected evolution with ecology.

  19. Ecology and Evolution • Beak size in Galapagos Finches

  20. Darwin’s Evolution ?

  21. Darwin’s Finches

  22. Trait Evolution • The evolution of traits relates to the evolution of species.

  23. Evolution facilitates speciation. How does speciation occur?

  24. Speciation occurs… • When two populations become different enough from each other.

  25. Species Concepts • Biological Species – a set of interbreeding populations. • Genetic Species – based on similarity of DNA. • Ecological Species – a set of organisms that occupy the same niche. • Phylogenetic Species – a group of organisms that share an ancestor and maintains its integrity through time and space. • Other: • Typological Species, Cohesion Species, Evolutionary Species, Morphological Species, Phenetic Species, Recognition Species, Mate-Recognition Species.

  26. Backing Up One Step…What Makes a Species Unique? One way to look at it: One species can be differentiated from another based on a differing set of traits.

  27. Traits: a functional unit of evolution • If you can describe how a trait evolved and why a trait is selected for then you can describe evolution.

  28. Evolution of Traits

  29. One More Case: • Color Vision Evolution in Monkeys

  30. What is colorblindness? Reduced ability to interpret light as color. 1 in 12 males are colorblind. < 1 in 100 females are colorblind.

  31. Are You Colorblind? • No (Female) • Yes (Female) • No (Male) • Yes, very (Male) • Yes, somewhat (Male)

  32. Agree or Disagree:It is nearly always advantageous to have trichromatic vision.(i.e. compared to dichromatic vision) • Strongly Agree • Agree • Neutral • Disagree • Strongly Disagree

  33. Agree or Disagree: Some humans probably have tetrachromatic vision. • Strongly Agree • Agree • Neutral • Disagree • Strongly Disagree

  34. Do you think YOU have tetrachromatic vision? • Yes (female) • No (female) • I have no idea • Yes (male) • No (male)

  35. Monkeysof the World TRICHROMATS DICHROMATS NEW WORLD OLD WORLD

  36. How Does Color Vision Work?Cell Biology:

  37. How Does Color Vision Work?

  38. Three types of Cone Cell • Different kinds of opsin proteins embedded in the membrane of cone cells. • Central Dogma of Molecular Biology: DNA  RNA  Protein Genes code for…. proteins Proteins are responsible for cell function

  39. 3.2a Opsin Image modified from Scientific American, April 09 11-cis-retinal Opsin • To produce the signal for color vision, retinal must stimulate the opsin protein but this cannot occur while the retinal molecule is in its cis- formation.

  40. 3.2b Opsin Image modified from Scientific American, April 09 11-cis-retinal Opsin • When 11-cis-retinal absorbs a photon (a basic unit of light), it changes from 11-cis-retinal to All-trans-retinal.

  41. 3.2c Opsin Image modified from Scientific American, April 09 All-trans-retinal Opsin • All-trans-retinal stimulates the opsin in the membrane of the cone cell.

  42. 3.2d SIGNAL Opsin Image modified from Scientific American, April 09 All-trans-retinal Opsin • The cone cell sends a signal to the brainthat is interpreted as colored light.

  43. 3.3 The Role of Opsins There are three types of opsins: Short Wave Sensitive (SWS) Medium Wave Sensitive (MWS) Long Wave Sensitive (LWS) An individual who produces only SWS and MWS opsin proteins will have dichromatic vision. An individual who produces SWS, MWS and LWS opsin proteins will have trichromatic vision. SWSMWS LWS

  44. Cone Cell Response to Light Image from www.answers.com/topic/photopsin

  45. MWS Opsin vs. LWSOpsin What’s the difference?

  46. 4.2 Location of Opsin Genes The gene coding for the SWSopsin protein is located on chromosome #7. The gene coding for the MWS and LWSopsins are located on the X-chromosome. Chromosome X1 Chromosome X2 Chromosome #7M Chromosome #7P

  47. 4.3 Origin of the LWS Opsin Gene The LWSgene arose through gene duplication and gene mutation of the MWS gene on the X-chromosome. GENE DUPLICATION GENE MUTATION Chromosome X Chromosome X Chromosome X

  48. 4.4 Gene Duplication

  49. 4.5 Unequal Crossing Over(Meiosis, Prophase 1) XP XM XP XM XP XM Prophase I Interphase S …Telophase II

  50. 4.3 Origin of the LWS Opsin Gene The LWSgene arose through gene duplication and gene mutation of the MWS gene on the X-chromosome. GENE DUPLICATION GENE MUTATION Chromosome X Chromosome X Chromosome X