bio exam 4 ch 18 & 15

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bio exam 4 ch 18 & 15
2013-07-26 15:33:10
evolution mtc section bio 101 Darwin natural selection

Darwin, evolution, origin of life
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  1. Important Dates in Geological Time
    Earth forms
    4.5 billion years ago
  2. Origin of Life
    4.0 - 3.0 billion years ago
  3. Oldest prokaryotic organisms
    3.5 billion years ago
  4. Earliest eukaryotic organisms
    1.5 billion years ago
  5. Earliest animals
    0.5 billion years ago
  6. 1862 - Louis Pasteur (France)
    • disproves the belief in "spontaneous generation"
    • life has to come from life
  7. 1920 - Alexander Oparin (Russia) & the early atmosphere
    • Oparin believed the early atmosphere consisted of
    • water vapor (H2O)
    • hydrogen (H2)
    • methane (CH4) and
    • ammonia (NH3)
    • but no molecular oxygen (free O2 by itself). This represented an atmosphere that contained not only the four essential elements in biochemistry but was also a "reducing atmosphere" that would favor the formation of more complex molecules necessary to form the first cells.
  8. 1953 - Stanley Miller (United States)
    • proved: Inorganic molecules can react to produce small organic molecules.
    • performed experiments to test whether the atmospheric conditions that Oparin suggested would allow the formation of the molecules necessary to form cells. Miller discovered that Oparin's reducing atmosphere was conducive to the formation of carbohydrates, proteins, nucleic acids, and lipids.
  9. Major Events Necessary to the Origin of Life on Earth
    • 1. Atmosphere must contain sources of carbon, hydrogen, oxygen, and nitrogen. 
    • 2. Large molecules (carbohydrates, lipids, proteins, and nucleic acids) must form from the smaller compounds in the atmosphere and primitive seas. 
    • 3. Cell membranes must form from the large molecules. 
    • 4. Genetic machinery must be installed within a cell to control replication and other cell functions. 
    • 5. Eukaryotic cells must evolve from prokaryotic cells.
  10. Proposed Early "Cells"
    • 1. coacervates - first cells had lipid-based membranes as proposed by Oparin.
    • 2. microspheres - first cells had protein-based membranes as proposed by Sidney Fox.
  11. Origin of the Cell's Genetic Machinery
    • The first cell is most likely RNA genes that are capable of replicating themselves & directing protein synthesis
    • Reverse transcription could have led to DNA genes
    • RNA was responsible for both DNA and protein formation
    • Eventually protein synthesis would have been carried out according to the central dogma, with information flowing from DNA to RNA to protein
  12. From Prokaryotic to Eukaryotic Cells
    • Prokaryotic cells preceded eukaryotic cells. The present structure of the eukaryotic cell was formed by enfolding the cell membrane
    • The mitochondria and the chloroplasts present in cells evolved from a bacteria-like organism (mitochondrion) and an alga-like organism (chloroplast) that invaded early cells and developed a favorable (mutualistic) association.
  13. eras oldest to youngest
    • PreCambrian
    • Paleozoic
    • Mesozoic
    • Cenozoic
  14. PreCambrian
    • 4.6 billion - 590 million years ago
    • No multicellular creatures; marine creature dominant; origin of prokaryotes and eukaryotes
  15. Paleozoic
    • 590 - 248 million years ago
    • Dominant animals include amphibians and fish; first vascular plants
  16. Mesozoic
    • 248 - 65 million years ago
    • Dominant animals include the dinosaurs; dominant plants include conifers
  17. Cenozoic
    • 65 million - present
    • Current era; dominant animals include mammals, dominant plants include flowering plants; modern man
  18. Evolution
    the changes that have transformed life on earth from its earliest beginnings to the diversity that exists today. Evolutionary biology provides a cohesiveness to nature and allows us to "make sense" of the world that surrounds us.
  19. Natural Selection
    • the theory proposed by Charles Darwin to explain the process of evolution
    • the mechanism that brings about adaptation to the environment as evolution occurs
  20. Aristotle (384-322)
    Believed species to be fixed and permanent; living things could be arranged on a scale of complexity Scala naturae (scale of nature)
  21. Carolus Linnaeus (1707-1778)
    • Swedish physician and botanist
    • the "father of modern taxonomy"; created a taxonomic system based on morphological (form and structure) comparisons. (kingdom, phylum, class, order, family, genus, and species)
    • created binomial nomenclature and standardized the language of taxonomy through the use of Latin.
    • Believed in the immutability of species, "God creates, Linnaeus arranges".
  22. Georges Cuvier (1769-1832)
    • French anatomist who developed the science of paleontology
    • developed theory of catastrophism: a belief that the boundaries between various fossil assemblages could be explained by catastrophic events occurring in earth's past
    • staunch opponent of evolution
  23. Charles Lyell (1797-1875)
    • English geologist who wrote Principles of Geology,
    • theory of uniformitarianism: which implied that geological processes are so uniform that their rates must balance out through time; implied an old age for the earth.
    • never fully accepted idea of evolution
  24. Jean Baptiste Lamarck (1744-1829)
    • theory of use and disuse, theory of inheritance of acquired characteristics (both discredited)
    • Lamarck emphasized
    • (1) that evolution was the best way to explain what can be observed in the fossil record
    • (2) the great age of the earth
    • (3) the important role the environment plays in the evolution of organisms.
  25. Erasmus Darwin
    Charles Darwin's grandfather who speculated about evolution as a process in Zoonomia (1794). His writings may have had some influence on his grandson's theories.
  26. Alfred Russell Wallace (1823-1913)
    Independently developed a theory of evolution by a process nearly identical to what Darwin referred to as "natural selection".
  27. Thomas Huxley
    English anatomist and physiologist; nicknamed "Darwin's Bulldog" due to his staunch defense of Darwin's view of evolution by natural selection.
  28. Charles Darwin (1809-1882)
    Developed the theory of evolution by natural selection (gradualism); in 1859 published The Origin of Species.
  29. Gregor Mendel
    Austrian monk considered the "father of Genetics" due to his research in 1865, but his research was unknown to Wallace and Darwin.
  30. 5) What group of islands observed during his voyage greatly influenced Darwin’s           thinking about evolution? where are they?
    • Galapagos Islands
    • off the coast of south america
  31. (6) Name 2 groups of animals that were observed on these islands that would            later be referenced in Darwin’s work on evolution?
    • finches
    • tortoises
  32. (12) Which scientist developed an idea very similar to that of Darwin, which encouraged Darwin to go ahead and publish?
    Alfred Russell Wallace
  33. (13) List 5 major points to Darwin’s theory of natural selection?
    • (1) Population tend to exhibit exponential growth; there is a tremendous potential in nature for overproduction of offspring. 
    • (2) Resources needed for survival are limited in nature, which leads to a struggle for survival.
    • (3) Individuals within populations vary. Some of these variations are more or less
    • advantageous in the struggle for existence. 
    • (4) The individuals with the best combination of characteristics will survive ("survival of the fittest"). 
    • (5) The survivors will have an opportunity to reproduce and pass the characteristics that gave them the survival edge on to their offspring.
  34. (14) What is meant by “fitness” in a Darwinian context? Would fitness necessarily mean the physically strongest organism?
    fitness: is the relative reproductive success of an individual (Barney Fife who has 5 kids is more fit than The Rock who has 0)
  35. adaptation
    Change that helps a species become more suited to its environment
  36. “Industrial melanism”
    English Pepper Moths - example of natural selection; darker moths were selected for survival as the industrial revolution wore on and pollution became more pronounced
  37. evidence that evolution has occurred
    • fossil record
    • biogeography
    • taxonomy
    • comparative anatomy
    • comparative embryology
    • molecular biology (biochemistry)
  38. fossils
    remains or evidence of some organism that lived long ago
  39. Transitional fossils
    are a common ancestor for two different groups of organisms
  40. Biogeography
    the distribution patterns of organisms
  41. Taxonomy
    classification which implies descent
  42. Comparative anatomy
    • homologous organs and structures
    • vestigial structures
  43. homologous
    parts of organisms that exhibit similar basic structures and embryonic origins
  44. analogous
    parts of organisms that are similar in function only
  45. vestigial structures
    remnant of a structure that was functional in some ancestor but is no longer functional in the organism in question
  46. Comparative embryology
    • All vertebrate embryos have:
    • A postanal tail
    • Paired pharyngeal (gill) pouches
  47. Molecular biology (biochemistry)
    • All living organisms:
    • 1. Use the same basic biochemical molecules
    • 2. Utilize same DNA triplet code
    • 3. Utilize same 20 amino acids in their proteins
    • DNA base-sequence differences: (cytochrome c)
    • When very similar, suggest recent common descent
    • When more different, suggest more ancient common descent