6 Charles Darwin ( ),In 1831, Charles Darwin sailed to the Galapagos Islands in the HMS Beagle.“Father of Evolution”Natural Selection
7 Alexander Oparinproposed that life began in the early oceans where a rich "primordial soup" of chemical compounds could build up. He suggested that energy from UV light and lightening could form these compounds.
36 Does Natural Selection depend On genotype or phenotype?PHENOTYPE
37 VIDEOEvolution: How Does Evolution Really Work? Click on Video for Students
38 FitnessAbility of an organism to survive and reproduce in its specific environmentDESERT: Sleep in cool dens
39 Adaptations Inherited characteristics that increases an organisms chance to surviveLeafcutter carries 50x’s its weightBig ears dissipate heat
40 Western Grebe Courtship Western Grebe Courtship MovieIn the “rushing” display, the mating pair swim side-by-sidewith their wings held back, theirlong necks arched, and their yellow beaks angled upward.
54 Common Descenttheory of universal common descent = all organisms on earth are descended from a common ancestor.
55 Darwin thought the Galapagos finches descended from finches of what country? Ecuador
56 We are more different than thought! Previous estimates of genetic similarity between humans and chimpanzees suggested they were 98.5–99% identical. However, after the sequencing of the chimpanzee genome 2005, the DNA similarity was fixed at 96%.Nature, the Chimpanzee Sequencing and Analysis Consortium, which is supported in part by the National Human Genome Research Institute (NHGRI), one of the National Institutes of Health (NIH),
57 Factors Affecting Natural Selection Food supplyDiseaseUnable to mateWeather natural selectionFitness of organisms
58 Most fossils are found in sedimentary rock. Where to find fossils?Most fossils are found in sedimentary rock.Examples of sedimentary rock are limestone, shale, and sandstone.
61 Historical Record of Organisms Youngest (on top) mammals/birdsNext reptilesNext amphibiansNext fishOldest (on bottom) prokaryotes
62 Assume thatSedimentary rock is laid down with the oldest rock layer on the bottom and the youngest rock layer on the top
63 Which is the most probable assumption about species A, B, and C ( In undisturbed rock layers)? 1. Species B is more abundant than species C.2. Species C existed before species B.3. Species A and B are genetically identical.4. Species B descended from species A.
64 #2 Species C existed before B ANSWER#2 Species C existed before B
65 When the industrial revolution arrived in England, the pollution had turned the bark of the trees a much darker color. Since light colored moths are much easier for birds to see on a dark background, they were preferentially eaten.
66 Some say this is not true! 1. Moths fly at night (so color would not be a factor).2. Moths don’t land on tree trunks; they hang on upper canopy tree limbs.
67 Secondary sexual characteristics: color, size, etc Secondary sexual characteristics: color, size, etc. different in males and femalesSexual Dimorphism
68 2. descent with modification Main Ideas of Darwin2. descent with modificationSee “gradualism” and “punctuated equilibrium”
69 Descent with Modification: Hawaii honeycreepers
70 So…descent with modification Evolution is a remodeling processDo you agree?
71 Darwin’s Ideas (cont.)3. Living species have arisen from earlier life-forms (common descent)
72 Common Descent Theories Phyletic GradualismPunctuated Equilibrium
73 Phyletic GradualismGradual changesYou would see transitional fossils (in-between forms)
98 Lucy: Man or Ape? Adult female - 25 yrs About 40% of her skeleton foundHer pelvis, femur (the upper leg bone) and tibia show her to have been bipedal.About 107 cm (3'6") tall(small for her species)About 28 kg (62 lbs) in weight.
99 Where did Lucy get her name? When the bones were found, the Beatles' song "Lucy in the Sky With Diamonds" was playing over during a night of dancing and drinking.
100 Dr. Donald Johanson recollects November 30, 1974, in Hadar, Ethiopia."I happened to glance over my right shoulder . . .and there on the surface of the ground was a little bit of an elbow, I recognized it immediately as belonging to a human ancestor.” (good eyes?)
101 Not A Human ArgumentsLucy’s DNA found she was indeed an ape (Cell magazine)-few skeletal bones which were usually fragmentary and often poorly preserved.-bones found far apart (1.5 miles away)
102 Other questions on Lucy Present day orangutan and spider monkeys have the same angle (pelvic and knees) as humans yet are extremely adept tree climbers.
103 And...Her brain size is still small, ape-like in proportionThe jaw, in particular, is distinct in that it is V-shaped, totally unlike human jaws.
104 PopulationGroup of individuals of the same species living in the same place at the same time.
105 What is...The smallest unit that can evolve?population
122 Molecular Biology Homologies: Similarities in blood, proteins and DNA and RNA sequences that indicate species relatedness; the greater the similarities, the more closely related two organisms are thought to be
123 Comparative Molecular Biology: Number of Amino Acid Differences with humans Gorilla 1Gibbon 2Rhesus monkey 8Dog 15Horse, cow 25Mouse 27So organisms with similar DNA or proteins would be more closely related
124 Darwinian FitnessContribution an individual makes to the gene pool of the next generation relative to the contribution of other individuals
125 The total collection of all genes in a population at one time. Gene PoolThe total collection of all genes in a population at one time.
126 Changes within a species ContrastMicroevolutionChanges within a speciesEXAMPLE: humans are getting tallerMacroevolutionSpecies change into other speciesEXAMPLE: reptile into a bird
127 MicroevolutionDarwin did in fact observe small changes, such as changes in the size and shape of finch beaks etc.
128 Macroevolution?Darwin never did see a finch turn into an iguana or visa versa (or any other such major change).Major changes are theorized to take millions of years.