1. EVOLUTION CONTINUED “Where’s the Evidence?!” Chap. 13 The Macroevolutionary Puzzle

2. Vocabulary Read (282-292) (740)(327) 109 paleontologist vestigial structure homologous structure gradualism punctuated equilibrium continental drift analogous character isotope 117 radioisotope

3. Radiometric Dating or Radioactive Dating Isotope- 1 form that an element can have. Number of neutrons is variable between isotopes of the same element. (number of electrons and protons stays the same) Minerals possess radioactive isotopes (give off energy and subatomic particles) that decay (breakdown) into smaller isotopes.

4. Formed in igneous rock, the minerals grow as the liquid rock cools. Amounts of the “parent” (or original) and “daughter” isotopes can be measured in a sample collected today. The rate of decay can be calculated experimentally. “Half Life” is a common unit of measure of the rate of break down.

5. p p p Atomic mass not changed much; atomic number increases by 1 because Neutron becomes proton (b) Beta decay Beta particle Radioactive parent nucleus Decay processDaughter nucleus Atomic mass not changed much; atomic number decreases by 1 (c) Electron capture Beta particle Atomic mass decreases by 4; atomic number decreases by 2 (a) Alpha decay Alpha particle Proton Neutron p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p Emission of 2 protons and 2 neutrons (alpha particle) An electron (beta particle) is ejected from the nucleus electron combines with a proton to form a neutron

8. Sample Problems The half-life of Potassium 40 is 1.3 million years. It breaks down into Argon 40 1) If an original rock sample contains 200 micrograms of Potassium 40, how much would remain after two half-lives?

9. Uranium 238 has a half-life of 4.51 billion years and decays into Lead 206 2) A newly discovered rock sample has 15 micrograms of Uranium 238 and 105 micrograms of the daughter material Lead 206. How old is this rock?

10. Homework 2 sides in binder The next 2 slides are more practice problems to work on later.

11. –U 238 decays into Pb 206 in 4.51 billion years (HALF LIFE) –How much U 238 and Pb 206 are present in a sample after 2 HALF LIVES? –(original sample is 300 grams) –U 238 75 grams Pb 206 225 grams –How long would 2 half lives be? –9.02 billion years

12. –How old is an igneous rock sample containing 275g U 238 and 1925g Pb 206 ? –3 x 4.51 = 13.53 billion years

13. V. EVIDENCE OF EVOLUTION FROM FOSSILS “any evidence of once living creatures” Where are fossils most likely to be found?

14. A. 4 Types of Fossils 1. Compression- organic material between layers of sediment, Some details can be observed. ex. fern frond, fish 2. Impression- external shape and form, no organic matter ex. foot print, limb print 3. Mold and cast- external features in one layer, then the item itself is replaced by other sediments ex. Egg, shark tooth 4. Petrifaction- tissues are gradually infiltrated by minerals. No organic material remains ex. petrified wood

15. 8_10 Rock broken to reveal external mold of shell Rock broken to reveal fossil cast Shells buried in sediment Mold, or cavity, forms when original shell material is dissolved Cast forms when mold is filled in with mineral water Shells settle on ocean floor How impression fossils form (the most common type)

16. BOG people Bogs filled with danger where you could easily get lost and drown. It's not hard to understand why tribes of long ago used to believe that gods and ghosts inhabited the swamps. Gifts and sacrifices were thought to win their good graces. Prehistoric man offered all kinds of objects to the bogs. So it was that bogs became gigantic offering locations.

17. Never before had there been so many bog bodies and offering all in one place. Schatten uit het veen provides an impressive picture of the beliefs and rituals of our ancestors in North-western Europe.

24. B. Distribution of fossils in layers of rocks? many varieties and great complexity first fossils were aquatic and some are extinct few varieties and little complexity OLDEST Fossils in every layer YOUNGEST STRATIFICATION

25. Each geologic time period is characterized by certain fossils (remember the GEO TIME TABLE?)

26. Why do organisms disappear from the fossil record? 1. unable to adapt to a changing environment Ex. lake drying, cooling climate,glaciers 2. out competed by organisms more suitable to the new environment Ex. reptiles competing with early mammals Or fish vs. amminoids

27. Diagram of species abundance over time Flowering plants and ferns

28. Diagram of species abundance over time Bony fish and amminoids

29. Notes in student binder GREAT! Less writing

30. VI CONTINENTAL DRIFT or PLATE TECTONICS Alfred Wegener early 20th century initially incorrect explanation but modified theory is widely accepted (seafloor stationary and continents move WRONG!!!!)

31. 10 MAJOR PLATES AND MANY MINOR PLATES UP TO 100 KM THICK Continents ride on the moving crustal plates (less dense material )

33. These are the possible events at the boundary of plates Slide Spread

35. These are the possible events at the boundary of plates Subduction Subduction w/continents

38. 1. Theory and Evidence OLD 1. puzzle pieces 2. fossil distribution 3. sediment layers "Gandwanan Sequence" similar geology on the 4 southern continents sandstone with coal black shale glacial till

40. NEW 1. earthquake distribution shallow quakes at ridges Mid Atlantic shallow and deep quakes at trenches subduction distribution of the RING OF FIRE pg 303 2. Movement of plates can be measured from space 3. Dating rocks on opposite sides of ridges Draw ring of fire on map

42. End of geological evidence * the earth is old and has changed (volcanoes, glaciers, earthquakes) * organisms that lived in the past are now gone * different organism appear in later rocks than in early ones therefore new organisms must be developing from old EVOLUTION

43. VII EVIDENCE OF EVOLUTION FROM LIVING CREATURES Common Ancestry through comparative anatomy Georges Buffon 1760 French Naturalist - observed the feet and legs of many animals - concluded that they were but variations on a single theme

47. "The ancestors of backboned animals must have had the same limb structure but has been modified for the life of the individual" *This suggests that organisms have changed with time and had a distant common ancestor **

48. What similarities must exist for organisms to have a common ancestor? 1. anatomy (talons, bones, coloration) 2. physiology (DNA, hemoglobin, digestion) 3. behavior ( instinct, learning)

49. Evidence of Evolution from living creatures continued HOMOLOGOUS STRUCTURES- organs or parts that are structurally similar but may have different functions (Indicates common ancestry or origin) SEE HANDOUT

53. ANALOGOUS STRUCTURES- same function but structurally different (bird and moth wing) Does not indicate any relatedness SEE HANDOUT

55. VESTIGIAL ORGANS- remnants of organs or parts that are believed to have been well developed in ancestors but have little function now. (genes are still present) (tailbone, appendix, pelvic bones, ) SEE HANDOUT

57. Vestigial organs Modern animals may have structures that serve little or no function –remnants of structures that were functional in ancestral species –evidence of change over time some snakes & whales show remains of the pelvis & leg bones of walking ancestors eyes on blind cave fish human tail bone

58. Vestigial organs Hind leg bones on whale fossils Why would whales have pelvis & leg bones if they were always sea creatures?

59. BIOCHEMICAL- organic compounds that are essential to certain processes (blood proteins, cytochrome C universal and essential to aerobic respiration, DNA, ribosomes) SEE LAB ACTIVITY

60. Molecular biology Comparing DNA & protein structure –universal genetic code! DNA & RNA –cytochrome C (respiration) protein structure –hemoglobin (gas exchange) protein structure Evolutionary relationships among species are documented in their DNA & proteins. Closely related species have sequences that are more similar than distantly related species.

63. Before comparing the amino acids Hypothesize on closely related pairs PairReason 1. 2. 3.

64. Before comparing the amino acids Hypothesize on unrelated pairs PairReason 1. 2. 3.

65. EMBRYOLOGICAL- the study of early developmental forms between organisms can suggest relatedness. (ex. larva forms may look similar though the adults do not) SEE HANDOUT

66. Comparative embryology Similar embryological development in closely related species –all vertebrate embryos have a gill pouch at one stage of development fish, frog, snake, birds, human, etc.

67. Building “family” trees Closely related species (twigs of tree) share same line of descent until their recent divergence from a common ancestor

68. PATTERNS OF EVOLUTION MORPOLOGICAL DIVERGENCE related organisms become less similar due to different environmental circumstances. Develop features to suit their habitat MORPHOLOGICAL CONVERGENCE organisms may have similar features but are unrelated. This results from being exposed to similar environmental conditions (ex. wombat vs. ground hog )

69. The Rate of Evolution Gradualism-(Darwin) small changes accumulate over a long period of time. (Transitional fossils would be expected) Punctuated Equilibrium- (Stephen J. Gould) long periods of uneventful time passes until a catastrophe creates opportunities for new species to flourish. Little change is punctuated by rapid evolution of new species.

71. Evidence of relatedness Example: Transitional forms in the fossil record Hypothesis: If terrestrial vertebrates (tetrapods) evolved from lobe-finned fish (sarcopterygians), then there should be transitional forms that possess traits that are intermediate.

72. Previously identified transitional forms From Ahlberg and Clack, Nature 2006

73. General Methods Scientists looked specifically for the transitional form of interest by sampling… –Appropriate habitats (stream system) –Appropriate geologic time (early Late Devonian = 385-376mya) From Daeschler et al., 2006 http://tiktaalik.uchicago.edu/photos.html

74. They found Tiktaalik roseae! From Ahlberg and Clack, Nature 2006 From Daeschler et al., Nature 2006 http://tiktaalik.uchicago.edu/photos.html

75. From Shubin et al., Nature 2006 http://tiktaalik.uchicago.edu/photos.html

76. Summary The study of and the evidence for evolution clearly fits within the scientific framework. We use current evolutionary theory to make and test hypotheses There are many thousands of examples of evidence for evolution

77. What about man? Where is the evidence of human ancestry?

78. What data from whole genome sequencing can tell us about evolution of humans

79. Example: the Evolutionary Hypothesis of Common Ancestry Chromosome Numbers in the great apes: 46 human (Homo)46 chimpanzee (Pan)48 gorilla (Gorilla)48 orangutan (Pogo)48 Testable prediction: If these organisms share a common ancestor, that ancestor had either 48 chromosomes (24 pairs) or 46 (23 pairs). Testable prediction: If these organisms share a common ancestor, that ancestor had either 48 chromosomes (24 pairs) or 46 (23 pairs).

80. Chromosome Numbers in the great apes (Hominidae): human (Homo)46 chimpanzee (Pan)48 gorilla (Gorilla)48 orangutan (Pogo)48 Testable prediction: Testable prediction: Common ancestor had 48 chromosomes (24 pairs) and humans carry a fused chromosome; or ancestor had 23 pairs, and apes carry a split chromosome. Centromere Telomere Ancestral Chromosomes Fusion Homo sapiens Inactivated centromere Telomere sequences

81. “Chromosome 2 is unique to the human lineage of evolution, having emerged as a result of head-to- head fusion of two acrocentric chromosomes that remained separate in other primates. The precise fusion site has been located in 2q13–2q14.1 (ref. 2; hg 16:114455823 – 114455838), where our analysis confirmed the presence of multiple subtelomeric duplications to chromosomes 1, 5, 8, 9, 10, 12, 19, 21 and 22 (Fig. 3; Supplementary Fig. 3a, region A). During the formation of human chromosome 2, one of the two centromeres became inactivated (2q21, which corresponds to the centromere from chimp chromosome 13) and the centromeric structure quickly deterioriated (42).” Homo sapiens Inactivated centromere Telomere sequences Hillier et al (2005) “Generation and Annotation of the DNA sequences of human chromosomes 2 and 4,” Nature 434: 724 – 731. Human Chromosome #2 shows the exact point at which this fusion took place Chr 2

82. Test topics evidence of evolution EVOLUTION TEST #2 Notes over Geological evidence of evolution Biological Evidence of Evolution Amino Acid Lab Radiometric Dating Text (282-292, 740, 327) Vocabulary (105-113) Worksheets x2 (History of Life and Evolution) Plate tectonics Map Know the continents Homologous vs. analogous Gradualism vs. Punctuated Equilibrium Comparative Anatomy Buffon (1-2-5)