gen bio2

• Spontaneous Generation
• Pasteur's contributions to science
• Pasteurization

  A method to prevent milk and wine from causing sickness
• Pasteur's experiment to disprove spontaneous generation

  In 1859, Pasteur boiled a meat broth in a flask with a curved neck that prevented particles from reaching the broth, putting an end to the theory of spontaneous generation
• All living beings, regardless of size, come from other living beings
• Extraterrestrial origins: Panspermia
• Supporters of Panspermia theory

  • Chemist Svante Arrhenius (1859-1927)
  • Astronomer Fred Hoyle (1915-2001)
• Life might have arrived on Earth in the form of bacteria carried by meteorites or sown by other intelligent extraterrestrial beings
• Conditions bacteria must have endured in their journey through space are extreme (ultraviolet radiation, extremely cold temperatures, etc)
• Supporters of Panspermia theory

  • Chemist Svante Arrhenius (1859-1927)
  • Astronomer Fred Hoyle (1915-2001)
• Panspermia does not answer the question of the Origins of Life
• Oparin's Hypothesis

  • The first organic molecules originated through reactions of gases of the primitive atmosphere using energy from electrical storms and ultraviolet radiation
  • Organic molecules gathered in the ocean for millions of years, forming a primordial soup where molecules reacted and became more complex
  • Some molecules were able to auto-replicate, leading to the formation of coacervates which later originated the first cells
• The Miller Experiment

  Stanley Lloyd Miller (1930-2007) reproduced conditions of the primitive atmosphere in his lab, forming small organic molecules like amino acids, proving life may have begun from a chemical evolution
• Biological Evolution is the change in inherited traits in one population over time, leading to a gradual transformation of simple living things into more complex species across generations
• Fixist Theories believed all species on Earth were invariable and stable, created as seen today, supported by a literal interpretation of the Bible
• Evidences in favor of Evolution

  • Fossils
  • Proof of an older Earth than described in the Bible
  • Plesyosaurus
• Mary Anning (1799-1847) was a famous British fossil collector who made significant discoveries, proving extinction with findings like the first specimen of Ichtyosaurus and the first Plesyosaurus
• Georges Cuvier (1769-1832)


  • Established extinction as a fact
  • Explained fossils with his theory of Catastrophism, attributing fossils to animals that died during past geological catastrophes
  • Believed in fixism, suggesting fossils were the result of "successive creations" to replace extinct species after each catastrophe
• Cuvier was a fixist: according to him fossils were the result of "successive creations" to replace the extinct species after each catastrophe. He counted up to 27 different creations
• Presumably, the last catastrophe had been the Universal Flood
• Erasmus Darwin belonged to the British Enlightenment movement
• Erasmus Darwin was a natural philosopher, doctor, abolitionist, and poet
• Erasmus Darwin refused to be King George III's personal physician
• In his work Zoönomia, Erasmus Darwin expressed views that foreshadowed a theory of evolution, which were read and commented on by his grandson Charles Darwin
• Erasmus Darwin advocated a proper education for girls
• Subjects Erasmus Darwin believed girls should learn


  • Physical exercise
  • Botany
  • Chemistry
  • Mineralogy
• Erasmus Darwin's evolutionary ideas were primitive and more poetical than scientifically grounded
• Erasmus Darwin's free-thinking had an important influence on his grandson Charles Darwin
• Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck, known as Lamarck, was a French soldier and naturalist
• Lamarck was the first to formulate a theory of evolution that included a mechanism
• Lamarck was one of the first to use the term "Biology" in its modern sense
• Lamarck's theory


  • The environment is able to induce changes in animals
  • Organisms have a drive to perfection, changing from simple to complex and better adapted
  • New organs develop if needed for a new function
  • Adaptation occurs when there is a change in the environment
  • Use and disuse affect organ development
  • Inheritance of acquired characteristics
• Weismann's experiment with mice tails disproved Lamarck's theory of inheritance of acquired characteristics
• Evolution by Natural Selection according to Charles Darwin

  1. Living beings produce larger offspring that can survive with limited resources

  2. Individuals in populations have small inheritable differences

  3. Only the fittest survive

  4. Survivors transmit their traits to offspring

  5. Accumulation of small variations through generations produce new adaptations
• Natural Selection according to Charles Darwin


  • Natural variability of inheritable traits in a population
  • Traits that give advantage to survival are favoured
  • Changes add over time through generations producing adaptations
• Survival of the fittest individuals

  They are more likely to survive and leave offspring, favoured by Natural Selection
• Effect of different characteristics on survival

  What Charles Darwin called Natural Selection
• Although Darwin continued studying different fields of science and corresponding with hundreds of scientists worldwide, he seemed in no hurry to publish the theory of evolution
• Darwin used to walk along his sandwalk in Downe House, thinking about his scientific theories
• Darwin knew his Theory of Evolution might bring problems with the Church and possibly didn't want to hurt his wife, Emma