Symbioses - Mutualism

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Symbioses - Mutualism
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Mutualism

• Definition - the individuals in a population of
  each mutualist species grow and/or survive and/or
  reproduce at a higher rate when in the presence
  of individuals of the other. Each benefits (,)

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Mutualisms involving Culture of Crops or Livestock
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Leaf-cutter Ants genus Atta
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Diagram of Leaf-cutter ant colony nest
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Human Agriculture
Sustainable Dairy Industrial Wheat
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Digestive Mutualisms Involving Gut Inhabitants
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Ruminant with multiple stomachs
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Ruminant by-products
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Termite Mound Western Australia
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Termites
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Mycorrhizae
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Ectomycorrhizae
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Ectomycorrhizae
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Mycorrhizae worlds largest organisms?

• The mycelium of some forest fungi can extend
  enormous distances. In 1992 a single individual
  of Armillaria bulbosa was discovered that
  permeates more than 30 acres of forest soil in
  northern Michigan and was thought to be one of
  the world's largest living organisms. It may have
  been spawned by a single spore thousands of years
  ago. In 1998 another species Armillaria solidipes
  in the Blue Mountains of Oregon was found to
  consist of a subterranean mycelial network
  extending across 2400 acres. It must weigh
  thousands of metric tons. Its age could be from
  2500 to 8400 years old.

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Armillaria solidipes
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VAM Vesicular Arbuscular Mycorrhizae
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Nitrogen Fixing Mutualisms
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Red Clover A Classic Legume
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Normal Nitrogen Fixation
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Legume Root Nodules
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Rhizobium root nodules on a bean plant
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Animal-Algae Mutualisms
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Healthy Coral Reef - Indonesia
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Coral polyp with zooxanthellae - a
dinoflagellate, Symbiodinium
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Coral polyp coral animal is green, Zooxanthellae
is red
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Endosymbiotic Origin of Eukaryotes
Lynn Margulis
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Endosymbiotic Origin of Eukaryotes
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Endosymbiotic Origin of Eukaryotes

• The earliest eukaryotes acquired mitochondria by
  engulfing alpha proteobacteria.
• The early origin of mitochondria is supported by
  the fact that all eukaryotes studied so far
  either have mitochondria or had them in the past.
  Mitochondria have their own DNA and replicate
  themselves during cell division.
• Later in eukaryotic history, some lineages of
  heterotrophic eukaryotes acquired an additional
  endosymbionta photosynthetic cyanobacteriumthat
  evolved into plastids.
• This hypothesis is supported by the observation
  that the DNA of plastids in red and green algae
  closely resembles the DNA of cyanobacteria.
• Plastids in these algae are surrounded by two
  membranes, presumably derived from the cell
  membranes of host and endosymbiont.

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Stromatolites on coast of Western Australia
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The Nature of Communities and Ecosystems
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Sourdough bread ingredients and final product
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Redwood Forest
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Scale of Ecosystem Lake Superior
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Scale of Ecosystem Isle Royale
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Scale of Ecosystem Isle Royale Forest and
Pond
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Scale of Ecosystem Isle Royale Wetland
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Scale of Ecosystem Isle Royale Pitcher Plants
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Ecotone region where two communities/ecosystems
grade into each other
Forest-Marsh Ecotone
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Stability

• A stable community or ecosystem is one that has
  the ability to replace itself exist in place
  for more than one generation

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Douglas-Fir
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Pea Aphids
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Life cycle of the Pea Aphid
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Components of Stability

• 2 major components
• 1) resistance - the ability of a community or
  ecosystem to avoid disturbance
• 2) resilience - the speed with which a community
  or ecosystem returns to its former state
  following a disturbance that has displaced it
  from its initial condition

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Ecosystems and Stability
Grassland South Africa Rainforest Puerto Rico
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Additional Components of Stability

• Local stability describes the tendency of a
  community to return to its original state
  following a small disturbance
• Global stability describes the tendency of a
  community to return to its original state
  following a large disturbance

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Adaptive Capacity of an Ecosystem
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Adaptive Capacity of an Ecosystem
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Adaptive Capacity of an Ecosystem- Chesapeake Bay
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Adaptive Capacity in 3D
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Current Adaptive Capacity
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From Local vs. Global Stability

• dynamically fragile - a community which is stable
  only within a narrow range of environmental
  conditions
• dynamically robust - a community which is stable
  within a wide range of environmental conditions