Development of Evolutionary Thought

• Famous Scientists

  1. Charles Lyell - Principles of Geology
  2. Charles Darwin - The Origin of Species
  3. James Hutton - Theory of Gradualism
  4. Jean Baptiste de Lamarck - Principles of Use and Disuse
  5. Thomas Malthus - Essay on the Principle of Population
  6. Carolus Linnaeus - Father of Taxonomy
• Carlos Linnaeus

  • Swedish naturalist and explorer, the first to frame principles for defining natural general and species of organisms.
  • Created a uniform system for naming them- the binomial nomenclature.
• Linnaean System of Classification

  • Most influential early classification system developed by Carlus Linnaeus.
  • All modern classification systems have their roots in Linnaeus' system.
• Carlos Linnaeus

  • Father of Taxonomy
  • In 1975, he published his classification system in a work called "Systema Naturae" (System of Nature).
• Taxonomy (As defined by Linnaeus):

  1. Kingdom
  2. Phylum (plural, phyla)
  3. Class
  4. Order
  5. Familu
  6. Genus
  7. Species
• Kingdom - highest taxon, major divisions of an organism. Examples are animal kingdom, plant kingdom, etc.
• Phylum (plural, phyla) - a division of kingdom. Phyla in the animal kingdom include chordates (internal skeleton) and arthropods (external skeleton).
• Class - a division of a phylum. Classes in the chordate phylum include mammals and birds.
• Order - a division of class. Orders in the mammal class include rodents and primates.
• Family -  a division of an order. Families in the primate order include hominids (apes and humans) and hylobatids (gibbons).
• Genus - a division of a family. Genera in the hominid family include Homo (humans) and Pan (chimpanzees).
• Species - taxon that is below the genus and the lowest taxon. Species in the Pan genus include Pan troglodytes and paniscus.
• Thomas Malthus

  • Author of the 1798 book, "An Essay on the Principle of Population."
  • English cleric, scholar, and influential economist.
  • He concluded that as more offspring are born, a more competitive nature would arise; more offspring also means fewer resources will be available.
• Georges Cuvler

  • Father of Paleontology
  • Theory of Catastrophism - boundaries represent floods, drought that destroyed many species.
  • According to him, all fossils are remains of extinct life forms.
• James Hutton's Theory of Gradualism

  • Profound changes can result from the cumulative effect of slow but continuous processes.
  • Also proposed that the Earth was shaped by geological forces occurring over very long periods of time.
• Charles Lyell's Principle of Geology

  • argued that the formation of Earth's crust took place through countless small changes occurring over vast periods of time, all according to known natural laws.
• Jean Baptiste de Lamarck

  • one of the first scientists to recognize that living things changed over time and that all species descended from other species.
  • Lamarckism - proposed that the characteristics that an animal acquired during its lifetime could be passed on to its offspring.
  • 1809 - published "Inheritance of Acquired Characteristics."
  • Inheritance of such a characteristic means its re-appearance in one or more individuals in the next or in succeeding generations.
• Evolution of Charles Darwin's Theory

  • Noticed that plants and animals were different from those he knew in Europe.
  • Spent a month observing life on the Galapagos Islands and realized that each island has different rainfall and vegetation and its unique assortment of plant and animal species.