last test

  1. microevolution
    •result of genetic changes, gives rise to new species
  2. macroevolution
    large-scale changes or trends that apply to groups of species
  3. natural selection
    • Encourages “survival of the fittest”
    • Individuals with certain traits are more likely to survive, reproduce, and pass the genes that encode those traits to their offspring

    • brings about adaptive evolution by acting on an organism’s phenotype consistently
    • increases the frequencies of alleles that enhance survival and reproduction
    • favors certain genotypes by acting on the phenotypes of certain organisms
  4. smog
    • Smoke + fog = smog
    • Constituents–Nitrogen oxides–Hydrocarbons–Eye and respiratory irritants–Small oil droplets, wood particles, coal ash, asbestos, lead, animal waste, dust
    • Major source: burning fossil fuels
    • Thermal inversion: atmospheric conditions that trap smog and prevent its dispersal
    • Control: air pollution abatement measures
  5. evidence of evolution
  6. biodiversty
    refers to species richness, the varity of living organisms on earth

    • Plants (through photosynthesis) recycle carbon dioxide for oxygen
    • Plants: source of medicines
    • Food sources
    • Stability of ecosystems
  7. sustainable world
  8. hominid
    Hominoids that are more human-like
  9. hominiod
  10. homo habilis
  11. homo sapiens
  12. homologous structures
    • body structures that share a common origin
    • Example: vertebrate forelimbs
  13. population growth
    • greatest:
    • least:
  14. genetic drift
    • describes how allele frequencies fluctuate unpredictably from one generation to the next
    • is significant in small populations.  The smaller a sample, the greater the chance of deviation from a predicted result
    • causes allele frequencies to change at random
    • can lead to a loss of genetic variation within populations
    • can cause harmful alleles to become fixed, tends to reduce genetic variation through losses of alleles
  15. gene flow
    • consists of the movement of alleles among populations
    • Alleles can be transferred through the  movement of fertile individuals or gametes (for example, pollen)
    • Gene flow is more likely than mutation to alter allele frequencies directly
    • Can increase or decrease allele frequencies & can induce speciation
  16. analogous structures
    features in distantly related groups

    Analogous traits arise when groups independently adapt to similar environments in similar ways
  17. Darwin developed 2 main ideas
    • Descent with modification explains life’s unity and diversity
    • Natural selection is a cause of adaptive evolution
  18. artificial selection
    Darwin noted that humans have modified other species by selecting and breeding individuals with desired traits

    Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals

    This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations
  19. Vestigial structures
    • body structures that no longer have a function but are homologous to structures in other organisms
    • Example: human coccyx
  20. Relative fitness
    is the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals
  21. founder effect
    • The founder effect occurs when a few individuals become isolated from a larger population
    • Allele frequencies in the small founder population can be different from those in the larger parent population
  22. bottle neck effect
    • The bottleneck effect is a sudden reduction in  population size due to a change in the environment
    • The resulting gene pool may no longer be reflective of the original population’s gene pool
  23. ecological footprint
    • The ecological footprint concept summarizes the aggregate land and water area needed to sustain the people of a nation
    • It is one measure of how close we are to the carrying capacity of Earth
  24. niche
    an organism’s role in a community
  25. Climax community
    • Succession ends with the establishment of the climax community
    • Most efficient, most varied, most stable
    • If disrupted, takes a long time to recover
  26. Decomposers
    Use dead organisms as energy source
  27. Omnivores
    Use either plants or animals as energy sources
  28. Biogeochemical cycles
    Include living organisms, geologic events, weather events
  29. Exchange pool
    (water, soil, atmosphere) water cycle
  30. Biomass
    producers consumers decomposers
  31. reservior
    • rocks
    • ocean sediments
    • fossil fuels
  32. eutrophication
    Rapid growth of plant life leading to death of animal life resulting from excessive organic or inorganic nutrients
  33. Carbon cycle
    • largely a gaseous cycle
    • –Carbon in living organisms is exchanged with atmospheric carbon dioxide
    • –Closely tied to photosynthesis and aerobic respiration
  34. nitrogen cycle
    • Nitrogen: essential component of proteins and nucleic acids
    • Atmosphere: largest reservoir of nitrogen
    • Nitrogen fixation: converts atmospheric
    • nitrogen to ammonium–Legumes (peas, alfalfa, soy beans)
    • Nitrification: converts ammonium to nitrate
    • Denitrification: converts nitrates back to nitrogen gas (N2)
  35. sedimentary cycle
    Phosphorus never enters the atmosphere
  36. Greenhouse effect
    • Gases let sunlight through, but trap heat from radiating back outward
    • Greenhouse effect responsible for:Global warming
  37. ozone
    • two different atmospheric locations–Pollutant in troposphere (near Earth’s surface)
    • Toxic, causes respiratory difficulties–Protective shield in the stratosphere
    • Shields the Earth’s surface from UV light
Card Set
last test