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EVOLUTION (:star: A Brief Account of Evolution (1938 (Coelacanth (S.Af) -…

- - - - Land reptiles
      - Went back to water
      - Evolve into fish like reptiles
- - - - Ethopia and Tanzania
        
        Ape-like
        
        Hairy and walked like gorilla and chimpanzee
        
        Hominid features
        
        Not taller than 4 feet
        
        400cc
  - - - Ethopia and Tanzania
        
        Man-like
        
        Hairy and walked like gorilla and chimpanzee
        
        Hominid features
        
        Not taller than 4 feet
        
        400cc
  - - - East Africa Grasslands
        
        Hunted using stone weapons
        
        Ate fruits
        
        Australopithecus africans
        
        450-700cc
        
        Australopithecus biosei
        
        615cc
  - - - East Africa
        
        Does not eat meat
  - - - Java (1891)
        
        First human-like hominid :red_flag:
        
        Ate meat
        
        650-800cc
  - - - Near E & C Asia
        
        Used hides to protect body
        
        Burried their dead
        
        1400cc
  - - - Africa
        
        Moved across continents
        
        Developed into different races
        
        Fossilis
        
        1650cc
        
        sapiens
        
        1450cc
- - - - Ontogeny recapitulates Phylogeny
  - - - Phylogenetic relationship
      - Common ancestor
      - Similar structures
      - Different functions
      - Thorns of Bougainvillea (and) Tendrils of Cucurbita
      - Limbs of man, cheetah, whale, bat
    - - No phylogenetic relationship
      - No common ancestor
      - Different structures
      - Similar functions
      - Wings of butterfly and birds
      - Eyes of octopus and mammals
      - Flippers of penguins and dolphins
      - Sweet potato(root modification) and potato(stem modification)
    - - Before
        
        Lichen present on barks
        
        Barks white in colour
        
        Black moth eaten by predators
        
        White survived
      - After
        
        Lichen disappeared
        
        Barks dark brown in colour
        
        white moth eaten by predators
        
        Black survived
      - "The conclusion"
        
        Evolution: stochastic process based on chance events in nature
      - Biston betularia
- - - - Convergent evolution
- - - - Fertilization: process of transfer of genetic material from parent to offspring
    - - (Brain drain) If organisms with particular trait leave the environment, then the old allele freq. data wouldn't help
    - - Changes caused in the genes due to mutagens(sudden changes)
    - - Association btw two chromosomes
    - - Stabilisation
        
        More individuals acquire mean character value
        
        Eg. Expression of grey (heterozygous) in moth
      - Directional change
        
        More individuals acquire value other than mean character value
        
        Eg. expression of either white or black in moth
      - Disruption
        
        More individuals acquire peripheral value at both ends of the distributive curve
        
        Eg. expression of both white and black in moth
- - - - Large differences arising suddenly in a population
      - Random
      - Directionless
      - Causes speciation--- Saltation
        
        Single step large mutation
  - - - Small
      - Directional
      - Gradual