Evolution<br />
Evolution = “Descent with Modification”<br />Organisms evolved due to being spread over different habitats and therefore a...
Evolutionary Adaptation</li></li></ul><li>Descent with modification<br />
Evolutionary Adaptation<br />
Evidence of Evolution:Fossil Record<br />Fossils chronologically ordered in rock layers<br />
Evidence of Evolution:Biogeography<br />Geographic distribution of species:			Australian marsupials<br />
HOMOLOGY<br />Evidence of Evolution:Comparative Anatomy and Embryology<br />
Evidence of Evolution:Molecular Biology<br />Notice that a Chimp is more genetically related to a human than to an Old Wor...
Adaptive Evolution<br />Natural Selection = Editing<br />The finches of The Galapagos Islands: The original finch develope...
Darwinism Meets Genetics<br />A population is the smallest unit of evolution.<br />Natural selection acts on individuals.<...
Analyzing Gene Pools<br />A Gene pool consists of all alleles (different forms a gene may have for a trait) in all the ind...
Practice Using The Hardy-Weinberg Formula<br />p2 + 2pq + q2 = 1<br />   p = 0.6	q = 0.4<br />What are the genotypic frequ...
Microevolution<br />1. Genetic Drift<br />      Def: A change in the gene pool of a small population due to chance.<br />T...
Genetic equilibrium- allele frequencies<br />remain constant.<br />To maintain equilibrium…<br />Random mating<br />Popula...
Types of Genetic Drift<br />a.  The Bottleneck Effect<br />An event that usually reduces the overall genetic variability i...
Microevolution Cont.<br />2.    Gene Flow<br />Def: The genetic exchange with another population.<br />3.    Mutations<br ...
<ul><li>Resistant Genes
Immediate Benefits
Long term Disaster
Evolution direct connection to daily lives</li></li></ul><li>Macroevolution<br />Def: Major biological changes evident in ...
The Origins of Species<br />Ernst Mayr<br />Studied the diversity of birds in New Guinea  (1927)<br />Biological species c...
   Zygote: fertilized egg
   Pre-zygotic (factors that impede mating between species or hinder fertilization of eggs if mating is attempted)
   Post-zygotic (mechanisms that operate should interspecies mating actually occur and form hybrid zygotes)</li></li></ul>...
Mechanisms of Speciation<br />Allopatric Speciation<br />A population forms a new species while geographically isolated fr...
<ul><li>Speciation occurs only with the evolution of reproductive barriers between the isolated population and its parent ...
If speciation occurs during geographic separation, the new species will not breed with its ancestral population, even if t...
Notice how the hybrid bread wheat has a set of chromosomes from each of its ancestors: T. monococcum (AA), Triticum (BB), ...
Relative Dating:Fossil Record<br />Fossils chronologically ordered in rock layers<br />
Radioactive Dating<br />
Continental Drift<br />
Meteor of this size would have lowered the temperature of Earth due to the blocking of the sun by atmospheric dust.<br />T...
The Origin of Life<br />Stage 1: Abiotic Synthesis of Organic Monomers<br />Amino Acids <br />Chains of nucleotides<br />C...
The Origin of Life<br />Stage 2: Abiotic Synthesis of Polymers<br />Monomers, such as amino acids, spontaneously fused tog...
The Origin of Life<br />Stage 3: Origin of Self-Replicating Molecules<br />inheritance<br />Ribozyme: catalytic RNA used t...
The Origin of Life<br />Stage 4: Formation of Pre-cells<br />Molecular packages with some properties of life.<br />The gap...
The origin of <br />eukaryotic cells<br />Endosymbiotic Theory<br />Membrane bound nuclear material<br />Organelles<br />M...
Concept Map<br />Section 17-2<br />Evolution of Life<br />Early Earth was hot; atmosphere contained poisonous gases.<br />...
Convergent Evolution<br />Process by which unrelated animals come to look like each other.<br />Dolphin<br />Penguin<br />...
Tempo of Evolution<br />Spurts of relatively rapid change<br />Slow adaptations<br />
Unrelated<br />Related<br />Intense environmental pressure<br />Similar environments<br />Inter-relationshiops<br />Small ...
Classifying the Diversity of Life<br />Systematics<br />Reconstructing evolutionary history<br />Radioactive dating = tool...
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Evolution_PMSD_Biology

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PowerPoint presentation that highlights chapters 13 and 14 in Campbell's Essential Biology (3rd. edition). It can also be used for Miller & Levine's Biology (2006 Ed.) for chapters 15-18.

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Evolution_PMSD_Biology

  1. 1. Evolution<br />
  2. 2. Evolution = “Descent with Modification”<br />Organisms evolved due to being spread over different habitats and therefore adapting and modifying themselves to fit the habitat.<br />Natural Selection <br /><ul><li>A population of organisms can change over generations if certain inheritable traits leave more offspring than others and those others get the chance to reproduce and continue the lineage.
  3. 3. Evolutionary Adaptation</li></li></ul><li>Descent with modification<br />
  4. 4. Evolutionary Adaptation<br />
  5. 5. Evidence of Evolution:Fossil Record<br />Fossils chronologically ordered in rock layers<br />
  6. 6. Evidence of Evolution:Biogeography<br />Geographic distribution of species: Australian marsupials<br />
  7. 7. HOMOLOGY<br />Evidence of Evolution:Comparative Anatomy and Embryology<br />
  8. 8. Evidence of Evolution:Molecular Biology<br />Notice that a Chimp is more genetically related to a human than to an Old World Monkey!<br />
  9. 9. Adaptive Evolution<br />Natural Selection = Editing<br />The finches of The Galapagos Islands: The original finch developed into 14 different species. What was the cause for the offshoots?<br />
  10. 10. Darwinism Meets Genetics<br />A population is the smallest unit of evolution.<br />Natural selection acts on individuals.<br />However the evolutionary impact of natural selection is only apparent in tracking how a population changes over time.<br />Population Genetics emphasizes the extensive genetic variation within populations and tracks the genetic make-up of populations over time.<br />Not all variation in a population is inheritable.<br />Only the genetic component of variation is relevant to natural selection.<br />Many variable traits in a population result from the combined effect of several genes.<br />Polymorphism<br />
  11. 11. Analyzing Gene Pools<br />A Gene pool consists of all alleles (different forms a gene may have for a trait) in all the individuals making up a population.<br />A reservoir for the next generation’s genes.<br />Recall: Homozygous (RR) and Heterozygous (Rr) Dominant and Recessive (rr)<br />Hardy Weinberg Formula (1908)<br />Helps to calculate the frequencies of genotypes in a gene pool from the frequencies of alleles and vice versa.<br />p2 + 2pq + q2 = 1<br />p = RR<br />pq = Rr<br />q = rr<br />
  12. 12. Practice Using The Hardy-Weinberg Formula<br />p2 + 2pq + q2 = 1<br /> p = 0.6 q = 0.4<br />What are the genotypic frequencies of their offspring?<br />0.36 + 2(0.24) + 0.16 = 1<br />36% RR<br />48% Rr<br />16% rr<br />
  13. 13. Microevolution<br />1. Genetic Drift<br /> Def: A change in the gene pool of a small population due to chance.<br />The best measure of Darwinian fitness is the number of fertile<br />offspring an individual leaves.<br />
  14. 14. Genetic equilibrium- allele frequencies<br />remain constant.<br />To maintain equilibrium…<br />Random mating<br />Population must be very large<br />No immigration or emmigration<br />No mutations<br />No natural selection<br />
  15. 15. Types of Genetic Drift<br />a. The Bottleneck Effect<br />An event that usually reduces the overall genetic variability in a population.<br />b. The Founder Effect<br />Genetic Drift in a new colony<br />i.e. The Galapagos Islands<br />
  16. 16. Microevolution Cont.<br />2. Gene Flow<br />Def: The genetic exchange with another population.<br />3. Mutations<br />A change in an organism’s DNA sequence.<br />Ultimate source of genetic variability.<br />4. Natural Selection<br />Directional Selection (selecting in favor of an extreme phenotype)<br />Disruptive (Diversifying) Selection (leads to a balance between two or more contrasting phenotypic forms)<br />Stabilizing Selection (maintains variation in a narrow range)<br />
  17. 17. <ul><li>Resistant Genes
  18. 18. Immediate Benefits
  19. 19. Long term Disaster
  20. 20. Evolution direct connection to daily lives</li></li></ul><li>Macroevolution<br />Def: Major biological changes evident in fossil record.<br />CONTRAST: MICROEVOLUTION<br />Speciation<br />Nonbranching evolution (transform a population enough for it to be designated a new species.)<br />Branching evolution (splits a lineage into two or more species)<br />
  21. 21. The Origins of Species<br />Ernst Mayr<br />Studied the diversity of birds in New Guinea (1927)<br />Biological species concept<br />Species = “groups of interbreeding natural populations that are reproductively isolated from other such groups.”<br />Reproductive isolation blocks exchange of genes between species and keeps their gene pools separate.<br /><ul><li> Reproductive barriers between species
  22. 22. Zygote: fertilized egg
  23. 23. Pre-zygotic (factors that impede mating between species or hinder fertilization of eggs if mating is attempted)
  24. 24. Post-zygotic (mechanisms that operate should interspecies mating actually occur and form hybrid zygotes)</li></li></ul><li>Isolating Mechanisms<br />Courtship<br />Sterile<br />
  25. 25. Mechanisms of Speciation<br />Allopatric Speciation<br />A population forms a new species while geographically isolated from its parent population.<br />Sympatric Speciation<br />A small population becomes a new species in the midst of a parent population<br />
  26. 26. <ul><li>Speciation occurs only with the evolution of reproductive barriers between the isolated population and its parent population.
  27. 27. If speciation occurs during geographic separation, the new species will not breed with its ancestral population, even if the two populations should come back into contact.</li></li></ul><li>Sympatric Speciation<br />Does not widely occur among animals but may account for over 25% of all plant species.<br />
  28. 28. Notice how the hybrid bread wheat has a set of chromosomes from each of its ancestors: T. monococcum (AA), Triticum (BB), T. turgidum (AA BB), T. tauschii (DD)<br />What can you notice about T. aestivum that might make it a good hybrid and the most important wheat species today?<br />
  29. 29. Relative Dating:Fossil Record<br />Fossils chronologically ordered in rock layers<br />
  30. 30. Radioactive Dating<br />
  31. 31.
  32. 32. Continental Drift<br />
  33. 33. Meteor of this size would have lowered the temperature of Earth due to the blocking of the sun by atmospheric dust.<br />Theory: 65 million years ago a catastrophic event occurred killing off the dinosaurs and about ½ of the species inhabiting the Earth in a 10 million year time span.<br />
  34. 34. The Origin of Life<br />Stage 1: Abiotic Synthesis of Organic Monomers<br />Amino Acids <br />Chains of nucleotides<br />Chains of DNA bases<br />Chains of RNA bases<br />Building blocks of protein<br />Sugars<br />Lipids<br />ATP<br />
  35. 35. The Origin of Life<br />Stage 2: Abiotic Synthesis of Polymers<br />Monomers, such as amino acids, spontaneously fused together to form proteins.<br />
  36. 36. The Origin of Life<br />Stage 3: Origin of Self-Replicating Molecules<br />inheritance<br />Ribozyme: catalytic RNA used to fuel RNA replication<br />
  37. 37. The Origin of Life<br />Stage 4: Formation of Pre-cells<br />Molecular packages with some properties of life.<br />The gap between pre-cells and true cells is enormous!<br />Natural Selection<br />
  38. 38. The origin of <br />eukaryotic cells<br />Endosymbiotic Theory<br />Membrane bound nuclear material<br />Organelles<br />More complex than prokaryotic cells<br />Ancestors to fungi, plants and animals<br />
  39. 39. Concept Map<br />Section 17-2<br />Evolution of Life<br />Early Earth was hot; atmosphere contained poisonous gases.<br />Earth cooled and oceans condensed.<br />Simple organic molecules may have formed in the oceans..<br />Small sequences of RNA may have formed and replicated.<br />First prokaryotes may have formed when RNA or DNA was enclosed in microspheres.<br />Later prokaryotes were photosynthetic and produced oxygen.<br />An oxygenated atmosphere capped by the ozone layer protected Earth.<br />First eukaryotes may have been communities of prokaryotes.<br />Multicellular eukaryotes evolved.<br />Sexual reproduction increased genetic variability, hastening evolution.<br />
  40. 40. Convergent Evolution<br />Process by which unrelated animals come to look like each other.<br />Dolphin<br />Penguin<br />Shark<br />
  41. 41. Tempo of Evolution<br />Spurts of relatively rapid change<br />Slow adaptations<br />
  42. 42. Unrelated<br />Related<br />Intense environmental pressure<br />Similar environments<br />Inter-relationshiops<br />Small populations<br />Different environments<br />Convergent evolution<br />Punctuated equilibrium<br />Adaptive radiation<br />Coevolution<br />Extinction<br />Flowchart<br />Section 17-4<br />Species<br />that are<br />in<br />under<br />under<br />form<br />in<br />in<br />can undergo<br />can undergo<br />can undergo<br />can undergo<br />can undergo<br />
  43. 43. Classifying the Diversity of Life<br />Systematics<br />Reconstructing evolutionary history<br />Radioactive dating = tool<br />The study of biological diversity: past and present<br />Taxonomy<br />Identification, naming and classification of species<br />Pioneer: Carolus Linnaeus (1707-1778)<br />Binomial Nomenclature<br />Homo sapien<br />
  44. 44. Hierarchical Classification<br />Which step is more specific? <br /> Class or Genus?<br />How is Domain Eukarya different from Bacteria and Archaea?<br />
  45. 45. Phylogeny<br /><ul><li>Evolutionary history of a species.
  46. 46. Tree is based on homologous structures, NOT analogous.
  47. 47. Two species will have more common nucleotide sequences based on how recently they branched from their common ancestor.</li></li></ul><li>The Cladistic Revolution<br />The Computer Age<br />
  48. 48. 6 Kingdoms vs. 3 Domains<br />Archaea-bacteria<br />Eubacteria<br />?<br />

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