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MACROEVOLUTION & SYSTEMATICS:CHAPTER 5
DEFINITIONSMicroevolution: genetic change in a population from one generation to the nextMacroevolution: Processes throu...
WHAT IS A SPECIES?   Biological species concept: If    organisms from two populations are    capable of breeding naturall...
SPECIATION   The formation of new species   Gene flow keeps populations    similar to one another.   Reproductive Isola...
SPECIATION: A TWO STEP PROCESS1.    Reproductive Isolation      Reduction of gene flow provides       opportunity for spe...
ANAGENESIS: “STRAIGHT-LINE”EVOLUTION Single species  evolving into  new species  over time
CLADOGENESIS: “BRANCHING”           EVOLUTION   Formation of    one or more    new species    from another    over time
3 TYPES OF SPECIATION  1.   Allopatric speciation-speciation in       organisms with no geographic       overlap.  2.   Pa...
ALLOPATRIC SPECIATION
MODELS OF SPECIATION
PARAPATRIC SPECIATION
SYMPATRIC SPECIATION
   Niche: the way of life of a    species (How that species fits    into the surrounding    environment)   Niche partiti...
NICHEPARTITIONING
SPECIATION RATERate  of Speciation: depends on # of empty nichesAdaptive  Radiation: Rapid diversification by a small # ...
TEMPO OF EVOLUTIONGradualism:   Macroevolution is a relatively slow and gradual process.Punctuated   Equilibrium: Long i...
THE BIRTH OF SPECIES                 b) Gradualism with                 increase in rate of                 change a) Grad...
EXTINCTION The disappearance  of a group of  organisms such as a  species. When a species  cannot change fast  enough to...
NEARLY EVERYTHING THAT HAS EVER LIVED IS EXTINCT
PALEOSPECIESPaleospecies: Identified in the fossil record based on physical similarities to and differences from other spe...
CLASSIFICATIONClassification is used to order organisms into categories to show evolutionary relationships.
LINNAEAN SYSTEM OF CLASSIFICATION   Hierarchical classification   Involves a number of    categories and    subcategorie...
HOW CAN WE MAKE SENSE OF ALL OFTHIS DIVERSITY?
PHYSICAL SIMILARITIES ARE ONLY USED TO CLASSIFY ORGANISMSIF THEY REFLECT EVOLUTIONARY RELATIONSHIPS   Analogous    traits...
NOT ALL HOMOLOGOUS TRAITS AREEQUALLY USEFUL FOR CLASSIFICATION   Ancestral trait: Trait    appearing early in    the evol...
USING DERIVED TRAITS TO BUILD               PHYLOGENIESDerived (Homologous)   Analogous Traits   Ancestral TraitsTraits
EVOLUTION OF THE COOTIEMOUTH     (PHYLOGENETIC TREE)
QUESTIONS1.   What is a phylogeny?2.   What is the difference between analogous and     homologous traits?3.   What is the...
HAVE A NICE DAY!
Lecture 10 macroevolution and systematics
Lecture 10 macroevolution and systematics
Lecture 10 macroevolution and systematics
Lecture 10 macroevolution and systematics
Lecture 10 macroevolution and systematics
Lecture 10 macroevolution and systematics
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Lecture 10 macroevolution and systematics

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Lecture 10 macroevolution and systematics

  1. 1. MACROEVOLUTION & SYSTEMATICS:CHAPTER 5
  2. 2. DEFINITIONSMicroevolution: genetic change in a population from one generation to the nextMacroevolution: Processes through which new species arise
  3. 3. WHAT IS A SPECIES? Biological species concept: If organisms from two populations are capable of breeding naturally and can produce fertile offspring, then they are classified in the same species. X = Horse Donkey Mule
  4. 4. SPECIATION The formation of new species Gene flow keeps populations similar to one another. Reproductive Isolation: genetic isolation of populations that may cause them to become incapable of producing fertile offspring. Gene flow is the glue that holds species together.
  5. 5. SPECIATION: A TWO STEP PROCESS1. Reproductive Isolation  Reduction of gene flow provides opportunity for speciation  Does not always lead to speciation2. Genetic Divergence  Other evolutionary forces change population enough so that fertile interbreeding is no longer possible
  6. 6. ANAGENESIS: “STRAIGHT-LINE”EVOLUTION Single species evolving into new species over time
  7. 7. CLADOGENESIS: “BRANCHING” EVOLUTION Formation of one or more new species from another over time
  8. 8. 3 TYPES OF SPECIATION 1. Allopatric speciation-speciation in organisms with no geographic overlap. 2. Parapatric speciation-speciation in organisms with partial geographic overlap. 3. Sympatric speciation-speciation in organisms with complete geographic overlap.
  9. 9. ALLOPATRIC SPECIATION
  10. 10. MODELS OF SPECIATION
  11. 11. PARAPATRIC SPECIATION
  12. 12. SYMPATRIC SPECIATION
  13. 13.  Niche: the way of life of a species (How that species fits into the surrounding environment) Niche partitioning: species evolve to occupy different niches and avoid competition  Ex. occupying different places in the habitat, feeding at different times, being active at different times of the year, etc.  Bees and moths use the same food resource  Bees diurnal, Moths nocturnal ☼ Can’t have two species occupying the same niche in the same area because this will lead to competition.
  14. 14. NICHEPARTITIONING
  15. 15. SPECIATION RATERate of Speciation: depends on # of empty nichesAdaptive Radiation: Rapid diversification by a small # of species to fill many open niches
  16. 16. TEMPO OF EVOLUTIONGradualism: Macroevolution is a relatively slow and gradual process.Punctuated Equilibrium: Long intervals of time with little change (stasis) interspersed with short intervals of rapid evolutionary change.
  17. 17. THE BIRTH OF SPECIES b) Gradualism with increase in rate of change a) Gradualism c) Punctuated Equilibrium = Staircase pattern
  18. 18. EXTINCTION The disappearance of a group of organisms such as a species. When a species cannot change fast enough to adapt to changes in its environment, it may become extinct.
  19. 19. NEARLY EVERYTHING THAT HAS EVER LIVED IS EXTINCT
  20. 20. PALEOSPECIESPaleospecies: Identified in the fossil record based on physical similarities to and differences from other speciesAssumption: physical similarity = genetic relatedness
  21. 21. CLASSIFICATIONClassification is used to order organisms into categories to show evolutionary relationships.
  22. 22. LINNAEAN SYSTEM OF CLASSIFICATION Hierarchical classification Involves a number of categories and subcategories reflecting evolutionary relationships  Kingdom  Phylum  Class  Order  Family  Genus  Species Carl Linnaeus
  23. 23. HOW CAN WE MAKE SENSE OF ALL OFTHIS DIVERSITY?
  24. 24. PHYSICAL SIMILARITIES ARE ONLY USED TO CLASSIFY ORGANISMSIF THEY REFLECT EVOLUTIONARY RELATIONSHIPS Analogous traits: Traits similar due to common function Homologous traits: Traits similar due to common ancestry
  25. 25. NOT ALL HOMOLOGOUS TRAITS AREEQUALLY USEFUL FOR CLASSIFICATION Ancestral trait: Trait appearing early in the evolution of a lineage Derived trait: Traits that are modified from the ancestral condition
  26. 26. USING DERIVED TRAITS TO BUILD PHYLOGENIESDerived (Homologous) Analogous Traits Ancestral TraitsTraits
  27. 27. EVOLUTION OF THE COOTIEMOUTH (PHYLOGENETIC TREE)
  28. 28. QUESTIONS1. What is a phylogeny?2. What is the difference between analogous and homologous traits?3. What is the difference between ancestral and derived traits4. What is the difference between microevolution and macroevolution?5. What is the biological species concept?7. What are allopatric, parapatric, and sympatric speciation?8. What is an adaptive radiation?9. How do you identify a paleospecies and what are the problems with this method?
  29. 29. HAVE A NICE DAY!

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