Community Ecology & Species Interaction (Exam 2)

  1. Mutualism
    • (+, +) both species benefit
    • EX - shrimp cleaning fish mouth and feeding off the remains
  2. Commensalism
    • (+, O) one species benefits and the other is not affected
    • EX - bird building a nest in a tree
  3. Consumption
    • (+, -) one species benefits at the expense of the other
    • EX - predator / prey
  4. Parasitism
    • (+, -) parasite feeds on host and gains nutrition from host
    • EX - house flies in owl
  5. Competition
    • (-,-) both species expend energy in the interaction
    • EX - animals fighting for same food source
  6. Intraspecific Competition
    between same species 
  7. Interspecific Competition
    between members of different species
  8. Niche
    role of an organism in the environment
  9. Fundamental Niche
    range of resources a species uses without competition 
  10. Realized Niche 
    range of resources a species uses with competition
  11. Niche Overlap
    2 species share a portion of their niche
  12. Competitive Exclusion Principle
    no 2 species can have the exact same niche and be able to coexist
  13. Niche Partitioning
    using the environment in slightly different ways to reduce competition
  14. 6 Types of Competition
    • 1. Consumptive: organisms consume same resources
    • 2. Preemptive: organisms occupy space, preventing access to resources
    • 3. Overgrowth: one organism grows over another
    • 4. Chemical: one species produces toxins that negatively affect another species
    • 5. Territorial: mobile organisms protect a feeding or breeding territory
    • 6. Encounter: organisms interfere directly for access to specific resources
  15. Disturbances
    anything that removes living organisms from an area
  16. Succession
    change in community structure over time
  17. 2 Types of Succession
    • 1. Primary Succession: disturbance that removes everything including soil
    • 2. Secondary Succession: disturbance that removes vegetation but not the top soil
  18. Species Diversity
    composition of a species in an area
  19. Species Richness
    how many species present 
  20. Species Evenness
    how many individuals of each species are present
  21. Diploid
    2 sets of chromosomes
  22. Haploid
    1 set of chromosomes
  23. Allele
    alternate forms of a gene
  24. Gene Pool
    all genetic info in the population
  25. Genetic Structure
    allele frequencies, genotype frequencies
  26. Hardy-Weinberg Theorem
    Frequencies of alleles & genotypes in a population's gene pool remain constant over the generations unless acted upon by agents other than sexual recombination
  27. Assumptions of the Hardy-Weinberg Theorem
    • 1. Infinitely large population size
    • 2. No gene flow (no immigration / emigration)
    • 3. No mutations 
    • 4. Random Mating
    • 5. No Natural Selection
  28. Evolution
    change in allele frequencies over time
  29. Difference Between Micro and Macroevolution
    • micro - genetic level
    • macro - speciation
  30. 5 Things That Cause Microevolution
    • 1. Genetic Drift
    • 2. Gene Flow
    • 3. Mutations
    • 4. Non Random Mating
    • 5. Natural Selection
  31. Two Scientists That Discovered Natural Selection
    Charles Darwin, Alfred Russel Wallace
  32. Fossil
    any trace of an organism that lived in the past
  33. Fossil Record
    all of the fossils that have been found and describe 
  34. 2 Ways of Aging Fossils
    • 1. Relative Aging: comparing where fossils are located relative to one another (deeper = older)
    • 2. Absolute Aging: Radiometric Aging
  35. Carbon 14 Half Life
    5600 years
  36. Uranium 238 Half Life
    4.5 billion years
  37. Who is Culvier and What Did He Accomplish
    discovered irish elk fossil and said that extinction is occuring
  38. Law of Succession
    extinct species are succeeded (followed by) similar species
  39. Transitional Forms
    fossil species with traits that are immediate between older and younger species
  40. Plate Tectonics
    movement of land masses 
  41. Vestigial Trait
    reduced or incompletely developed structures that have reduced or no functions that clearly ressemble organs in other species

    EX - coccyx (tail bone) in humans
  42. Analogy
    species with common characteristics but not by common descent

    EX - flight in birds & insects
  43. Phylogeny
    evolutionary history of a group of organisms 
  44. Homology 
    similarity between different species because of common ancestory 
  45. 3 Types of Homologies
    • 1. Structural: similarities in morphology of organism (form)
    • 2. Developmental: overall morphology of embryo
    • 3. Genetic: look at nd compare sequence of nucleotides
  46. Natural Selection
    Best adapted to environment reproduces and survives
  47. 4 Steps of Natural Selection
    • 1. individual variation in traits
    • 2. traits have a genetic basis that is heritable
    • 3. only a subset of the offspring produced each year survive
    • 4. the survivors are the ones that have traits that best adapt them to the environment (naturally selected)
  48. 3 Modes of Natural Selection 
    • 1. Directional Selection: selects against one extreme trait in favor of the other traits
    • 2. Stabilizing Selection: selecting against both extremes in favor of average.
    • 3. Disruptive Selection: selecting against average in favor of the extreme traits, leads to speciation
  49. Sexual Selection
    best traits to attract a mate will get to reproduce and pass genes on to the next generation
  50. Sexual Dimorphism
    males and females have different forms
  51. What are the 2 Components of Sexual Selection
    • 1. Female Choice
    • 2. Male-Male Competition
Card Set
Community Ecology & Species Interaction (Exam 2)
community ecology and species interaction exam 2