Chapter 11

  1. LUCA
    Last Universal Common Ancestor
  2. Extant
    not extinct (still alive)
  3. Phylogenetic Event Horizon
    point in history in which phylogenic analysis cannot possibly see [LUCA represents a phylogenetic event horizon]
  4. RNA World
    RNA is the basis of life
  5. Prebiotic Soup Hypothesis
    pool of molecules that existed in liquid form before life arose—developed over time, grown more diverse via matter arriving on extraterrestrial objects known to carry amino acids, purines, and pyrimidines--energy from lightning, volcano, internal heat, cosmic rays
  6. Miller-Urey Experiment
    simulation of the "prebiotic soup hypothesis"--found that amino acids (the building blocks of life) formed
  7. Spiegelman Experiment
    Tested RNA for heritability and observed natural selection acting on the mutations
  8. Ribozymes
    RNA enzymes (not proteins--less stable and efficient than proteins)
  9. Mutualism
    beneficial interaction between two species that increases fitness
  10. Molecular Mutualism
    two or more molecular substrates combine in a positive way to replication--important for replicators
  11. Hypercycle Model
    rate of replication of one replicator is dependent on the concentration of the preceding replicator--relies on molecular mutualism [i.e. A --> B --> C --> D --> A]
  12. Altruism
    species interaction in which only one party benefits, and the other suffers negative consequences
  13. Protocell
    primitive cell (membrane)
  14. Benefits of protocell (encapsulation)
    • increases concentration of replicators
    • control microenvironment inside the cell
    • creating chemical gradients across membrane
    • cell membrane as defense mechanism
    • partitioning various functions
  15. Transposon Mutagenesis
    technique for systematically disrupting gene function
  16. Essential Genes
    • energy metabolism
    • regulatory function
    • fatty acid/lipid metabolism
    • synthesis of nucleotides
    • transcription
    • DNA metabolism
    • protein binding
  17. Minimal Gene Set
    • Genes that are critical for proper function
    • 16: assoc w/ gene metabolism
    • 106: linked to RNA metabolism
    • 15: processing/folding proteins
    • 56: energetic/intermediate metabolism
    • 13: other cellular processes
Card Set
Chapter 11
Origin and Evolution of Early Life