genbio 2

• Biodiversity


  The variety of earth's species, the genes they contain, the ecosystems in which they live, and the ecosystems processes such as energy flow and nutrient cycling that sustain all life
• Biodiversity is a vital renewable resource
• Biodiversity sustains us and our economies
• Major components of earth's biodiversity

  • Functional diversity
  • Ecological diversity
  • Genetic diversity
  • Species diversity
• Functional diversity


  The biological and chemical processes such as energy flow and matter recycling needed for survival of species, communities, and ecosystems
• Ecological diversity


  The variety of terrestrial and aquatic ecosystems found in an area or on the earth
• Genetic diversity


  The variety of genetic material within a species or a population
• Species diversity


  The number and abundance of species present in different communities
• Biological Evolution by Natural Selection

  Explains how life changes over time
• Major components of Biological Evolution

  • Study of the Fossil Record
  • Biological Evolution (genes changing in populations)
  • Natural Selection (certain traits out survive others)
• Biological Evolution by Natural Selection is the major scientific theory that explains how life has changed over the last 3.5 billion years
• Mutations


  Change genes in cells
• Adaptive Traits


  Improve ability to survive and most lead to differential reproduction
• Genetic Resistance


  Allows organisms to tolerate chemicals designed to kill it
• Three Major adaptations of humans

  • Strong opposable thumbs
  • Ability to walk upright
  • Complex brain
• These adaptations helped us develop technologies, tools, and devices, to help our survival
• Environmental changes can lead to adaptations only for genetic traits already present in a population's gene pool or for traits resulting from mutations
• The populations ability to adapt may be limited by its reproductive capacity
• Species that reproduce quickly adapt in a short time, species that reproduce slowly adapt in a long time
• Three Common Myths about Evolution through Natural Selection

  • It is "Survival of the Fittest" not "Survival of the strongest" (reproductive success)
  • Organisms develop traits because they need or want them (genes are already present)
  • Evolution by natural selection involves some grand plan of nature in which species become more perfectly adapted (appears to be random)
• Location of continents and oceans influence climate


  Which determine where animals and plants can live
• Movement of continents


  Allows species to move, adapt, and form new species through natural selection, or become extinct
• Earthquakes and volcanoes


  Can separate and isolate populations, or destroy and habitats wiping out populations
• Climate change


  Can occur rapidly killing off species and allowing other species to fill their roles. This also changes areas of habitability
• Asteroid impacts


  Have also affected evolution through natural selection
• Plate Tectonic Movement will change the Earth in 100 million years
• Speciation


  Two species arise from one
• Geographic Isolation


  Different groups of the same population of a species become physically isolated from one another for long periods
• Reproductive Isolation


  Mutation and change by natural selection operate independently in the gene pools of geographically isolated populations
• Artificial selection


  Humans are playing an increasing role in the process of speciation by shuffling genes
• Genetic engineering


  Humans are playing an increasing role in the process of speciation by shuffling genes
• Extinction


  Where an entire species ceases to exist
• Endemic Species


  Are especially susceptible to extinction
• Background Extinction


  Is where species disappear at a slow rate
• Mass Extinction


  Is where large numbers of species are wiped out
• Extinction is a natural process, but much evidence indicates humans are major contributors to premature extinction
• Golden Toads located in Costa Rica's Monteverde Cloud Forest Reserve have become extinct due to changes in climate. It's habitat has dried up due to changes in climate
• Species Diversity


  The number of different species contained in a community
• Species Richness


  One component of species diversity
• Species Evenness


  One component of species diversity