evobio

• Evolution


  A change in the genetic composition of a population over time
• Descent with modification


  The gradual appearance of all biological diversity
• Reasons for evolution

  • Mutation
  • Migration
  • Genetic drift
  • Natural selection
• Evolution only occurs when there is a change in gene frequency within a population over time
• Genetic differences are heritable and can be passed on to the next generation
• Evolution results in long-term change
• Andreas Vesalius


  • Comparative anatomy, observations no more relying on text by ancient expert, animals have many anatomical similarities to animals and places us in the natural world

  
• William Harvey and William Paley


  • Observation, Harvey understand natural world by envisioning living things as machines, Paley was a proponent of natural theology, mechanisms are the products of divine creation, discovered blood was pumped from the heart
• Nicholas Steno


  • Birth of paleontology, fossils are not oddly-shaped rocks; evident of past life, sediments were laid down in layers trapping organisms, preserving snapshots of life at different points in the history of earth

  
• Carolus Linnaeus


  • Binomial and hierarchies, organized life into hierarchy of classification (KPCOFGS)
• George Louie Leclerc-Comte de Buffon


  • Old Earth ancient life, Earth is old, understand its history in terms of natural processes, life has history and natural process, explain its origins and subsequent change, proposed species shared ancestors instead of arising separately
• Thomas Malthus


  • Human populations subjected to same basic laws of nature as other, growth outstrip the resources available to support population
• Georges Cuvier


  • Extinction happens! During occasional catastrophic events on Earth, did not believed in organisms evolved, organisms function perfectly, any change would destroy balance
• William Smith


  • Biostratigraphy, Smith discovered that using fossils, rock layers can be identified in order they formed with use if fossils
• Jean Baptiste-Lamarck


  • Evolution happens through natural processes, mechanisms of inheritance of acquired characteristics and internal force that cause life to evolve into more complex
• Inheritance of Acquired Characteristics

  Organisms adapt to its environment, changes passed to offspring, evolution of new and improved adaptions
• Theory of use and disuse


  By using or not using body parts, an individual tends to develop certain characteristics, passed to offspring, species evolved as a result of interactions with environment, genes cannot be altered by any effort by an organism
• Karl Ernst von Baer


  • Developmental similarities, embryology does not reflect a progression from lower to higher, but many have have similar developmental stage
• Charles Lyell


  • Uniformitarianism, same processes occur
• Charles Darwin


  • British Naturalist (1809 - 1882), provided evidence that existing species have evolved from pre-existing ones, theory of Evolution by Natural Selection, observed the similarities among many discrete species and noted the differences that enabled them to be adapted to their environmental conditions (Finches in Galapagos Islands)

  
• Darwin's theory of evolution by natural selection

  • Overproduction
  • Variation
  • Competition
  • Differential reproductive success
• When populations are separated, natural selection on two separate populations can produce two distinct populations with different characteristics resulting in two separate species
• Microevolution


  Changes of a population over time
• Macroevolution


  The formation of species

  
• Evidences supporting the theory of evolution

  • Fossil records
  • Fossil dating (biostratification)
  • Radiometric dating
  • Comparative anatomy of related species
  • Distribution of plants and animals
  • Related species have similar patterns of development
  • Molecular comparisons between organisms

  
• Five related theories


  • Perpetual change
  • Common descent
  • Multiplication of species
  • Gradualism
  • Natural selection
• Gregor Mendel


  • Chromosomes and mutation, concluded inheritance is not blending parental traits, but rather passing discrete genetic units from parents
• Ernst Haeckel


  • Early evolutionary development, common ancestry can be seen on development of an organism, ontogeny recapitulates phylogeny
• Alfred Russel Wallace


  • Biogeography, species distribution is the result of its evolutionary history, co-discoverer of theory natural selection, explored amazon basin (1848-1852), sent Darwin an unpublished manuscript to read prior to its publication

  
• Alfred Wegener


  • Continents once formed a super continent and have split apart
• Thomas Henry Huxley


  • Human evolved over time, known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution, agnostic, believes that the human mind could not go beyond limits
• Eugene Dubois


  • Human evolved over time, Dutch anatomist and geologist, discovered the remains of Java man, the first known fossil of Homo erectus
• Thomas Hunt Morgan


  • Chromosomes contain hereditary materials, mutation to chromosomes have small effects, 1910, study fruit fly detected mutant male fly (white eyes not red)
• Fisher, Haldane and Wright


  • Random mutation, mathematical models in study of evolution, evolution driven by small mutations, not drastic ones
• Theodosius Dobzhansky


  • Modern synthesis, combine genetics and natural history to show mutations, genetic variability, and isolation act to create new species, integrate the data and theory of genetics, paleontology, systematics, other sciences
• Ernsy Mayr


  • Speciation, geographic isolation important in the accumulation of genetic differences, incipient species
• Clair Patterson


  • Earth is 4.5 byo, enough time for evolution by natural selection
• Lynn Margulis


  • Organisms from very distinct lineages joined together symbiotically and formed new lineages
• James Watson and Francis Crick

  • Discovered structure of DNA lead to understand mutation, changes in DNA, drive evolution
• Stephen Jay Gould


  • Modern evo-devo, changes in regulatory genes that affect development is important source of variation for evolution, study development and how genes control development can tell us about evolution