02. EVOLUTION, BIOLOGICAL COMMUNITIES & SPECIES INTERACTIONS

• Adaptation


  The acquisition of traits that allow a species to survive in its environment
• Acclimation


  When an individual organism can respond immediately to a changing environment
• Genetic traits


  Traits passed from generation to generation that allow a species to live more successfully in its environment. This process of adaptation to environment is explained by the theory of evolution
• Evolution


  The basic idea that species change over generations because individuals compete for scarce resources
• Natural Selection


  The process of better-selected individuals passing their traits to the next generation
• Mutations


  Changes to the DNA coding sequence of individuals that occurs occasionally, and the changed sequences are inherited by offspring
• Limiting factors of species

  • Physiological stress due to inappropriate levels of some critical environmental factor
  • Competition with other species
  • Predation, including parasitism and disease
  • Luck
• Critical factor


  According to the chemist Justus von Liebig (1840), it is the single factor in shortest supply relative to demand that determines where a species lives
• Tolerance limits


  The minimum and maximum levels of environmental factors beyond which a particular species cannot survive or is unable to reproduce
• Habitat


  The place or set of environmental conditions in which a particular organism lives
• Ecological niche


  Describes both the role played by a species in a biological community and the set of environmental factors that determine its distribution
• Generalists


  Species that tolerate a wide range of conditions or exploit a wide range of resources
• Specialists


  Species that have a narrow ecological niche
• Allopatric speciation


  Speciation that occurs when populations are geographically separated
• Sympatric speciation


  Speciation that occurs within one geographic area
• Directional selection


  The shift toward one extreme of a trait
• Taxonomy


  The study of types of organisms and their relationships
• Binomials


  Identify and describe species using Latin or Latinized nouns and adjectives, or names of people or places
• Competition


  A type of antagonistic relationship within a biological community where organisms compete for limited resources
• Intraspecific competition


  Competition among members of the same species
• Interspecific competition


  Competition between members of different species
• Predator


  Any organism that feeds directly on another living organism, whether or not this kills the prey
• Symbiosis


  Two or more species live intimately together, with their fates linked
• Mutualism


  A type of symbiosis in which both members benefit
• Commensalism


  A type of symbiosis in which one member clearly benefits and the other is neither benefited nor harmed
• Parasitism


  A form of predation that may also be considered symbiosis because of the dependency of the parasite on its host
• Endosymbiosis


  One species living inside another one
• Ectosymbiosis


  One species living on the surface of the other species
• Keystone species


  Plays a critical role in a biological community that is out of proportion to its abundance
• Primary productivity


  The rate of biomass production, an indication of the rate of solar energy conversion to chemical energy
• Abundance


  An expression of the total number of organisms in a biological community
• Diversity


  A measure of the number of different species, ecological niches, or genetic variation present
• Ecological structure


  Patterns of spatial distribution of individuals and populations within a community, as well as the relation of a particular community to its surroundings
• Constancy


  Lack of fluctuations in composition or functions
• Inertia


  Resistance to perturbations
• Renewal


  Ability to repair damage after disturbance
• Ecotones


  The boundaries between adjacent communities
• Closed community


  A community that is sharply divided from its neighbors
• Open community


  A community with gradual or indistinct boundaries over which many species cross
• Ecological succession


  The history of community development