bio quiz

• Evolution


  Change of species over time
• Artificial Selection


  • Intentional/selective breeding of plants or animals
  • People get to select which organisms to reproduce
• Natural Selection


  • Process through which populations of living organisms adapt and change
  • Heritable traits that help organisms survive and reproduce become more common in the population over a period of time
  • Traits that improve survival or reproduction accumulate in population
  • Adaptive change
  • Survivors have advantageous traits
• Genetic Drift


  • Allelic drift/sewall wright effect
  • Change in the frequency of a gene variant (allele) in a population due to random sampling of organisms
  • In contrast with natural selection
  • Frequency of traits changes in a population due to chance events
  • Random change
  • Survivors are lucky because it is random
• Both Natural Selection and Genetic Drift

  • Ways of how population change/evolve
  • Cannot operate unless there is genetic variation
• Mutation


  Change in the DNA
• Recombination


  • Pieces of DNA are broken and recombined to produce new combinations of alleles
  • Crossing-over during meiosis
• Andreas Vesalius: Comparative Anatomy


  • He began to notice that Galen had made mistakes
  • Wrote a book about his new discoveries called De humani corporis fabrica libri septem, or "The Seven Books on the Structure of Human Body" and commonly known as Fabrica
• Nicholas Steno: Fossils and the Birth of Paleontology


  • Birth of paleontology: a day in 1666 when two fishermen caught a giant shark off the coast of Livorno in Italy
  • Shark teeth resembled "tongue stones", triangular pieces of rock that had been known since ancient times
  • Declared that the tongue stones indeed came from the mouths of once-living sharks
  • Proposed the law of superposition
• John Ray: The "Species" Concept


  • He established the modern concept of species (organisms of one species do not interbreed)
  • Used fossils as the basic unit of taxonomy
  • Studied fossils, recognizing them as having formed from once-living organisms
  • Was deeply religious and rejected the possibility of an old and changing Earth
• Thomas Robert Malthus: The Ecology of Human Populations


  • Made his groundbreaking economic arguments by looking at humans as groups of individuals who were subject to the basic laws of behavior
  • Pointed out that the same forces of fertility and starvation that shaped the human race were also at work on animals and plants
• Carl Linnaeus: The Modern Taxonomic System


  • Took up the idea that plants reproduce sexually, using differences in reproductive structures to develop a system for classifying plants
  • Gave all his specimens a descriptive Latin binomial, or two-word name
• Georges-Louis Leclerc, Comte de Buffon: Evolution and the Age of the Earth


  • Set out the current knowledge of the whole of natural history in "Natural History" ("Histoire Naturelle")
  • Contributed to the debate over the age of the Earth, suggesting that our planet had formed in a molten state and that its gradual cooling must have taken far longer than the 6000 years
• Erasmus Darwin: Thoughts on Evolution


  • His book "The Loves of the Plants" introduced the public to the intricacies of plant taxonomy and reproduction
  • Said that life on Earth could be descended from a common ancestor in his book, "Zoonomia"
• Georges Cuvier: Contribution to Paleontology and The Catastrophism Model of Earth's History


  • His work was useful in interpreting the remains of the fossil animals and relating them to living species
  • Classified animals according to their body plan
  • His extensive studies of fossils gave rise to paleontology
  • Recognized that particular groups of fossil organisms were associated with certain rock strata
  • Used the concept of Catastrophism, explaining how large numbers had become extinct
  • Thought that life had existed unchanged on Earth for hundreds of thousands of years
• Jean-Baptiste Lamarck: Concepts of Evolution and Inheritance


  • Views on species were the opposite of Cuvier's
  • Proposed that individuals were able to pass to their offspring characteristics acquired during their own lifetime
  • Explained further that evolution produced more complex organisms from simple ancestors, and that this process of change took time
• Etienne Geoffroy Saint-Hillaire: Concepts of Evolution and Inheritance


  • Elaborated Lamarack's views
  • Suggested that if these environmental changes were harmful, then the organism would die and only those well-adapted to the environment would survive
• James Hutton: Principle of Uniformitarianism


  • Saw that there was no need for global catastrophes to shape the surface of the Earth
  • Given sufficient time, the gradual ongoing processes of erosion, sedimentation, and uplift could produce the geological features he saw (Principle of Uniformitarianism)
• Charles Lyell: Principles of Geology


  • Collected a large amount of supporting evidence of uniformitarianism and set this out in the "Principles of Geology"
  • Considered the origins of plants and animals
  • Recognized that many species had become extinct and been replaced by others
• Charles Robert Darwin: Theory of Evolution by Natural Selection


  • Left on the Beagle on what was to be a five-year voyage on December 27, 1831
  • His thinking was enormously influenced by the work done by previous scientists
  • Read Lyell's book and accepted the principle of Uniformitarianism first hand in South America
  • Found evidence supporting Lyell's theory
  • Noticed the variation of the Galapago Islands' giant tortoises from island to island but its significance only struck him after his return to England (Darwin's Finches)
  • Developed his theory of evolution by natural selection as a coherent explanation for his observations on the form and distributions of species, tying it into the concepts developed by others
  • Quickly produced an outline but took 25 years refining it while gathering supporting evidence
• Alfred Russel Wallace: Theory of Evolution


  • Came up with the idea that the best-adapted organisms in a population would survive to breed, passing on their adaptations to their offspring
  • Corresponded with Darwin, asking for comments and assistance on his papers
• The Theory of Evolution by Natural Selection


  • Darwin and Wallace both had the same concepts but even after both being read at a meeting at the Royal Society, Darwin's contribution is what we remember today
  • "On the Origin of Species by Means of Natural Selection, or the preservation of favored races in the struggle for life" was published in 1859
• Observations


  • Organisms of all species can produce so many offspring that their population size would increase exponentially if all individuals that are born reproduce successfully
  • Populations tend to remain stable in size, except for seasonal fluctuations
  • Environmental resources are limited
  • Individuals of a population vary extensively in their characteristics; no two individuals are exactly alike
  • Much of this variation is heritable
• Inferences


  • Production of more individuals than the environment can support leads to a struggle for existence among individuals of a population, with only a fraction of offspring surviving each generation
  • Survival in the struggle for existence is not random, but depends in part on the hereditary make-up of the surviving individuals. Those individuals whose inherited characteristics best fit them to their environment are likely to leave more offspring than less-fit individuals
  • This unequal ability of individuals to survive and reproduce will lead to a gradual change in a population, with favorable characteristics accumulating over the generations
• Simpler Explanation


  • Natural selection = differential reproductive success
  • Natural selection occurs as a result of interaction between the environment and genetic variability in the population
  • The outcome of natural selection is the adaptation of populations to their environment