EVOLUTION Darwin’s Theory Slides 1 – 24 1

Consider This… “ Individual organisms live, reproduce and die. Individuals, however, do not evolve; populations do. Evolution is the change in gene frequency that occurs in a population over time. ” Audesirk, T. & Audesirk G. Biology – Life on Earth. 4 th edition. © 1996 Population: all the individual members of a particular species living in a given area. 2

Biological evolution… Is NOT “just a theory.” In science, theory ≠hypothesis Has NO political agenda. Does NOT have a direction. Has NO ultimate goal. Was NOT discovered by Darwin. Misconceptions 3

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Pre-Darwinian Evolutionary Ideas Jean Baptiste de Lamarck (1744 – 1829) French Biologist First complete explanation of evolution (1809) Inheritance via acquired characteristics – Claim: Organisms transform their appearance to produce evolution. 5 Giraffe necks = evidence?

Charles Darwin 1831 At only 22 years old, this British nature lover went for a 5-year cruise onboard her majesty’s Beagle ship. He sailed around the world to look at stuff. The most famous stop being the Galapagos islands off the coast of South America. 6

Biodiversity VARIATION! 7

VARIATION / Biodiversity 8

Beaks differ 9

Abundant babies!!!!! 10 OVERPRODUCTION!

Blue feet? 11 ADAPTATIONS ?

Adaptation Book definition: A trait that helps an organism survive and reproduce. 12

Darwin ’ s Notes Observation 1: Overproduction – Organisms make more offspring than can survive. Observation 2: Resources are Limited. Conclusion 1: Competition for survival and reproduction among species. Observation 3: Individuals Differ from one another within a species ’ population. Conclusion 2: Fitness – the most well-adapted individuals from one generation will usually leave the most offspring. 13

Twenty Years Later Darwin finally publishes his book On the Origin of Species, sharing his theory of Evolution by Natural Selection (1859). 14

Terms Evolution change in a population ’ s genes from one generation to the next. a.k.a. change over time. Natural Selection Nature selects who stays!! This process drives evolution. 15 Adaptation- A trait that helps an organism to survive & reproduce (born with it). Adaptations are favorable variations. Variation- Differences between individuals of the same species. Examples: color, shape, size, behavior, chemistry. Variations come from: Mutations. Meiosis Cross Over (challenge topic)

Populations will have a pool of genes. A gene pool is all the genes that occur in a population. 16

17 Five Fingers of Micro- Evolution

18 THE FAT CAT ATE THE RAT. THE FAT CAR ATE THE RAT. Mutations workshop… DNA Replication Mutation

19 Australopithecus (Genus)4 myaGenus of Hominids (Family). “Lucy” 3.2 mya (Ethiopia) Extinct Homo habilis2.33 – 1.44 mya Short, long arms. Primitive stone tools. Extinct. Homo erectus1.9 mya – 143,000 years ago “Upright man” Homo neanderthalensis Homo sapeins neanderthalensis (?) 600,000 – 350,000 years ago Interbreeding? Climate change? Homo sapiens200,000 years ago “intelligent” Homo sapien sapiens Extant! Modern humans. Extant. Common Ancestry

MUST KNOW Evolution Vocab Adaptation Branching tree Competition Common ancestor Darwin, Charles Evolution Extinct Fossil Fossil Record Gene pool Gradualism 20 Half-life Homologous structures Mutation Natural selection Overproduction Punctuated equilibria Radioactive element Relative dating Scientific theory Species Variation

More Evolution Vocab SHOULD KNOW Analogous structures Artificial selection Cast Coevolution Mold Perpetual change Petrified fossil Lamarck Vestigial structures CHALLENGE Altruism Convergent evolution Disruptive selection Founder effect Genetic drift Sexual selection Stabilizing selection 21

Name 3 Misconceptions about EVOLUTION: 22 1) 2) 3)

Turn & Talk to Complete this frame: 23 micro EVOLUTION MACROEVOLUTION

What did Darwin OBSERVE? 24 #1) #2) #3)

What did Darwin CONCLUDE? 25 #1) #2)

Evolution, part II Oh yea, PROVE IT! 26 Proof Fossils Comparative Anatomy Comparative Embryology Vestigial Structures Comparative Biochemistry

Evidence 27

Recall that a scientific theories… Are well supported. By appropriate & sufficient evidence. Explain many observations Are testable. Are widely accepted. Incorporate facts, laws, inferences and tested hypotheses. Are NOT “ just a theory. ” 28 Thermodynamics Evolution Gravity

29 Pangaea 200 mya

Evidence for Evolution Biogeography Ex: Galapagos species Fossils Ex: Horses Homologies Ex: Anatomy DNA & Proteins Ex: Human FGF2 Gene Mathematical Models Population simulation Artificial Selection Ex: Antibiotic resistance 30

Fossil Evidence Fossils are the remains of past life dug up from the earth ’ s crust. Fossil formation is rare. Most fossils form in sedimentary rock. Fossils are the historical documents of biology. 31 Examples: bone, teeth, casts, impressions. Because the Earth ’ s crust is layered over time, younger fossils are found closer to the top.

Why are primate fossils rare? 32 1) Most primates did not live in habitats that readily preserved fossils, such as swamps and shallow lagoons. 2) Until recently, primates were fairly small. 3) Ancestral primates may have had small populations, thus providing less material for fossilization in the first place. FYI - Primate evolution has been linked to grasping hands, binocular vision and a LARGE brain.

Fossil Record Evidence If you piece together all the millions of fossils that scientists have dug up and sequence them by time (age), you have the Fossil Record. How do you know a fossils age? Relative dating Top vs. Bottom layers. Radioactive dating Unstable element decay of nearby rocks. 33

Embryology Evidence Looking at the early development of one organism and comparing it to another allows scientists to make inferences about their evolutionary relationship. Embryo: Not yet born, developing multicellular organism. Inference: using clues to make a conclusion. 34

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Homologous Structures Evidence Definition: similar structures that related species have inherited from a common ancestor. 36

Biochemical evidence Results from DNA & protein analysis further support the theory of evolution by natural selection. 37

Summary Evolution by means of natural selection explains the history of life on earth. This claim is supported by abundant evidence. Key Concepts are: Species share common ancestors. Descent with modification: (perpetual change) Nature chooses which species stay (extant) and which go (extinct). 38

Class Discussion Which is more likely to form a fossil Jellyfish or crab? Why are there gaps in the fossil record? How do you interpret an evolutionary tree diagram? 39

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7) High School Challenge Describe the role that geographic isolation can play in speciation. Speciation = new species formation. Research: Allopatric speciation Vicariant vs. founder effect. Sympatric speciation 45

Darwin ’ s Work 1. Variation: There is Variation in Every Population. 2. Competition: Organisms Compete for limited resources. 3. Offspring: Organisms produce more Offspring than can survive. 4. Genetics: Organisms pass Genetic traits on to their offspring. 5. Natural Selection: Those organisms with the Most Beneficial Traits are more likely to Survive and Reproduce. 46

The History of Evolutionary Thought Plato (Greek philosopher B.C.E.)- Aristotle (Plato ’ s student BCE)- 47

High School Challenge Lamarck v. Darwin Who is Jean-Baptiste Lamarck & how did his take on evolution differ from Darwin ’ s? Hardy-Weinberg equation p 2 +2pq+q 2 =1; p+q=1 48