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(Evolution) - Coggle Diagram

- - - - Biological Species Concept
        
        Interbreeding populations
        
        Reproductively isolated
        
        Limitations: fossils, asexual species
      - Morphological Species Concept
        
        Based on physical traits
        
        Useful for fossils
      - Ecological Species Concept
        
        Based on ecological niche
      - Phylogenetic Species Concept
        
        Smallest group on evolutionary tree
    - - Prezygotic Barriers
        
        Habitat isolation
        
        Temporal isolation
        
        Behavioral isolation
        
        Mechanical isolation
        
        Gametic isolation
      - Postzygotic Barriers
        
        Reduced hybrid viability
        
        Reduced hybrid fertility
        
        Hybrid breakdown
    - - Geographic isolation
      - Genetic divergence
      - Examples: squirrels on Grand Canyon
      - Evidence: lab experiments, natural examples
    - - No geographic barrier
      - Mechanisms
        
        Polyploidy
        
        Autopolyploid
        
        Allopolyploid
        
        Sexual selection
        
        Habitat differentiation
      - Common in plants
    - - Hybrid zones
        
        Reinforcement
        
        Fusion
        
        Stability
      - Outcomes
        
        Strengthening of barriers
        
        Weakening of barriers
        
        Continued formation of hybrids
    - - Gradualism vs Punctuated Equilibrium
      - Punctuated pattern
        
        Sudden changes
      - Gradual pattern
        
        Slow, steady change
      - Speciation time estimates
        
        4,000 40 million years
  - - - Formation 4.6 BYA
      - Conditions
        
        Volcanic activity
        
        Little oxygen
        
        Lightning & UV radiation
      - Abiotic synthesis of molecules
        
        Miller-Urey experiment
      - Protocells
        
        Membranes + RNA-like molecules
      - RNA world hypothesis
        
        Self replicating RNA before DNA
    - - Fossil record
        
        Incomplete but informative
      - Types of fossils
        
        Casts, preserved remains, trace fossils
      - Dating methods
        
        Relative dating
        
        Radiometric dating
        
        Half lives
        
        Carbon-14, Uranium 238
      - Geological time scale
        
        Eons: Hadean, Archaean, Proterozoic, Phanerozoic
        
        Eras: Paleozoic, Mesozoic, Cenozoic
    - - Five major extinctions
      - Permian Extinction
        
        96% marine species lost
        
        Volcanic activity
      - Cretaceous Extinction
        
        Asteroid impact
        
        Loss of dinosaurs
      - Effects on biodiversity
        
        Opens niches for survivors
        
        Leads to adaptive radiation
    - - Rapid evolution of many species
      - Triggered by:
        
        Mass extinctions
        
        New traits
        
        New habitats
      - Examples
        
        Mammals after dinosaurs
        
        Hawaiian silverswords
    - - Plate tectonics
      - Pangaea formation and breakup
      - Geographic isolation
      - Climate changes
      - Explains distribution of fossils
    - - Changes in developmental genes
      - Hox genes
        
        Control body plan
      - Heterochrony
        
        Changes in timing
      - Paedomorphosis
        
        Retaining juvenile traits in adults