1. Phylum
    2. 1. Classification of Animals
    2. Protozoa
    3. Porifera
    4. Coelenterata
    5. Platyhelminthes
    6. Nemathelminthes
    7. Annelida
    8. Earthworm
    9. Arthropoda
    10. Cockroach
    11. Mosquito
    12. Honey bee and Silk moth
    13. Mollusca
    14. Echinodermata
    15. Hemichordata
    16. Chordata
    17. Pisces
    18. Amphibia
    19. Frog
    20. Reptile
    21. Aves
    22. Mammalia
    23. Rabbit bone
  2. Animal Behaviour and Adaptation
    3. 24. Animal behaviour
    25. Animal adaptation
    26. Migration
  3. Developmental Biology
    4. 27. Development of Animals
    28. Development of Frog
  4. Human Biology
    5. 29. Tissues
    30. Sense organs
    31. Digestive system
    32. Circulatory system
    33. Respiratory system
    34. Nervous system
    35. Endocrine system
    36. Reproductive system
    37. Excretory system
    38. Skeletal system
    39. Basic concept of Immunology
    40. Human diseases
  5. Evolutionary Biology
    6. 41. Origin of Life
    42. Organic Evolution
    43. Theories of Evolution
    44. Evolution of Human beings
    45. Horse Evolution
Evolutionary Biology
43. Theories of Evolution
LAMARCKISM
Founder
Name
Jean Baptiste de Lamarck
Details
  1. French naturalist
  2. First to suggest complete theory of organic evolution
  3. Published in 'Philosophie Zoologique'
  4. Severely criticized by Cuvier
Postulates
  1. Internal forces increase body size
    2. ◈ Formation of New Organs: Result of continuous needs (Doctrine of Appetency)
  2. Organ development proportional to use (Use and Disuse)
    3. ◈ Inheritance of Acquired Characters:
    1. Most controversial postulate
    2. Known as Lamarckian Doctrine
Key Concepts
  1. Direct influence of environment on individuals
  2. Weismann's disproval (tail-cutting experiment in mice for 80 generations)
  3. Weismann's 'Theory of Continuity of Germplasm'
  4. Neo-Lamarckism: Only germplasm-affected characters are heritable
Examples
  1. Webbed feet in aquatic birds
  2. Long-necked giraffes
  3. Limbless snakes
DARWINISM
Founders
Charles Darwin
  1. British naturalist
  2. Voyage on HMS Beagle (1831)
  3. Influenced by Malthus' 'Principle of Population'
Alfred Russel Wallace
  1. Developed similar ideas independently
  2. Joint paper 'Origin of Species' with Darwin
  3. Darwin's detailed book: 'On the Origin of Species by Means of Natural Selection'
Postulates
  1. Overproduction
    2. ◈ Struggle for Existence:
    1. Intra-specific (high competition)
    2. Inter-specific
    3. With environment
  2. Heredity and Variation
  3. Natural Selection (Survival of the Fittest - Spencer)
  4. Structural modifications for changing environment
  5. Origin of Species
Drawbacks
  1. Focused only on minute fluctuating variations
  2. Didn't distinguish somatic vs germinal variations
  3. Pangenesis theory (discarded explanation for inheritance)
  4. No satisfactory explanation for variations
  5. Didn't account variation with heredity
  6. Neo-Darwinism incorporates mutations + natural selection
Examples
    ◈ Overproduction:
    1. Fast reproducers: Paramecium, Housefly, Oyster, Salmon
    2. Slow breeder: Elephant
  1. Variations in Galapagos tortoises and finches
  2. Long-necked giraffes
  3. Industrial melanism in peppered moth (Biston betularia)
  4. Dinosaur extinction
  5. Sickle-cell anemia
  6. Mosquito DDT resistance
NEO-DARWINISM
Basis
Variation
Chief Contributors
  1. Weismann
  2. Mendel
  3. De Vries
MUTATIONTHEORY
Founder
Name
Hugo de Vries
Details
  1. Dutch botanist
  2. Experimental plant: Oenothera lamarckiana (Evening primrose)
KeyConcepts
  1. Mutations = Discontinuous variations ('Sports' - Darwin, 'Saltatory variations' - Bateson)
  2. Generally harmful and recessive
  3. Source of genetic variations in evolution
  4. May or may not be inherited
  5. Germinal mutations are inheritable
ExplanatoryPower
  1. Progressive/retrogressive evolution
  2. Persistence of vestigial and overspecialized organs
  3. Struggle for existence + Survival of fittest with useful mutations
  4. Speciation
AdditionalPoints
  1. X-rays induce hereditary variations in plants
  2. Selected mutations increase in population frequency
  3. Greater evolutionary potential in sexually reproducing species
  4. Evolution impossible without genetic variations
MODERNSYNTHETICTHEORY
Components
  1. Genetic variations (mutations, recombination)
  2. Natural selection
  3. Reproductive isolation
  4. Genetic drift
Example
Human evolution
COMPARATIVETABLE
Theory
Key Mechanism
Inheritance Mechanism
Strengths
Weaknesses
Lamarckism
Use/Disuse + Acquired Characters
Inheritance of acquired traits
Explains adaptation to needs
No germplasm concept
Darwinism
Natural Selection
Pangenesis (discarded)
Explains survival adaptations
No genetic basis for variations
Mutation Theory
Saltatory variations
Germinal mutations
Explains sudden changes
Most mutations harmful
Neo-Darwinism
Natural Selection + Mutations
Mendelian inheritance
Combines genetics & selection
Complex mechanisms