Interactions Among Living Things

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Interactions Among Living Things
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Adapting to the Environment

• Natural Selection a characteristic that makes
  an individual better suited to its environment
  may eventually become common in that species.
• Natural selection results in adaptations or
  behaviors and physical characteristics that allow
  organisms to live successfully in their
  environments.
• (you will hear more about this during Evolution)

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Interactions Among Living Things

• Organisms have adaptations that help them survive
  in their environment

• All organisms have their own Niche.
• Niche is the role of an organism in its
  environment or how it makes its living.
• NICHE INCLUDES
• type of food the organisms eats
• how it obtains this food
• which other organisms use this organism as food
• when and how it reproduces
• physical conditions it requires to survive

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Three types of Interactions among Organisms

• Competition
• Predation
• Symbiosis

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COMPETITION

• The simultaneous demand by two or more organisms
  for limited environmental resources, such as
  nutrients, living space, or light.

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PREDATOR/PREY

• Predator- organisms that obtain their nutritional
  energy by killing and eating other organisms.
• Prey Any creature that is hunted and caught to
  be eaten for food.

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Symbiosis
Organisms within a community interact with each
other in many ways. Some are predators, some are
prey. Some compete with one another, some
cooperate. Some species form symbiotic
relationships with other species
Mutualism benefits both
Commensalism benefits one, other unaffected
Parasitism benefits one, harms other
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SYMBIOTIC RELATIONSHIPS

• MUTUALISM-An association between organisms of two
  different species
• in which each member benefits.
• EXAMPLE

Example Rainforest ants and the Whistling Thorn
and Bullhorn Acacia trees. ants nest inside the
plant's thorns. ants protect acacias from attack
by herbivores (which they frequently eat,
introducing a resource component to this
service-service relationship)
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• Commensalism- the relation between two different
  kinds of organisms when one receives benefits
  from the other without affecting or damaging it.

• Barnacles adhering to the skin of a whale or
  shell of a mollusk barnacle is a mollusks that
  benefits by finding a habitat where nutrients are
  available. (In the case of lodging on the living
  organism, the barnacle is transported to new
  sources of food.)
• The presence of barnacle populations does not
  appear to hamper or enhance the survival of the
  animals carrying them.

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PARASITISM

• symbiosis in which one organism lives as a
  parasite in or on another organism and usually
  does some harm to it.
• Hosts is the
• organism that the
• parasite lives
• on

Ticks on a bird
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Competition

• It is the struggle between organisms as they
  attempt to use the same limited resource
• Occurs when two species occupy
• the same niche
• Why cant two species occupy the same niche?
• If two species occupy the same niche, they will
  compete directly against each other and one
  species will eventually die off

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• In Australia Rabbits compete with herbivores
  like the western Quoll which became extinct
• Rabbits were brought in they were an invasive
  species whose destruction of habitats is
  responsible for the extinction or major decline
  of many native animals such as the Western Quoll.

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Predation

• The interaction in which one organism kills
  another for food is called predation
• The organism that does the killing is the
  predator
• The organism that is killed is the prey

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Adaptations

• Predator adaptations
• Help them catch and kill prey
• Cheetah can run very fast for a short time
• Jellyfishs tentacles contain a poisonous
  substance that paralyze tiny water animals
• Prey adaptations
• Help them avoid becoming prey
• Alertness and speed of an antelope help protect
  it from its predators
• Smelly spray of a skunk

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Predation and Population Size

• Predator and prey populations rise and fall in
  related cycles.

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Predation
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Defense Strategies
False Coloring
Mimicry
Protective Covering
Warning Coloring
Camouflage
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Changes in Communities
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Ecosystems are always changing
Primary Succession a series of changes that
occur in an area where no soil or organisms
exist. In a barren area, a new community is
established with pioneer species (first species
in the area), like mosses, that do well with
little or no soil. Mosses eventually give way to
coniferous trees.
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Ecosystems are always changing
Secondary Succession a series of changes that
occur in an area where the ecosystem has been
disturbed. When a disturbance (fire, flood, or
tornados) damages a community but soil remains,
the community gets reestablished from seeds and
roots left behind. Grasses grow, then small
shrubs, and eventually trees.
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Types of Succession

• Secondary
• After a blowout
• Re-establish a community
• Already had living organisms
• Fire, flood, human disruption

• Primary
• 1st time plants
• or animals are
• established
• New island
• Volcanoes
• Bare soil, rock

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Pioneer species

• Are the first plants to grow in an area
• Lichens (algae fungi) break apart rock to make
  soil
• Grasses
• Annual flowers
• Mosses

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Succession communities
2. Intermediate species
3. Climax community

• Pioneer
• species

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Intermediate Community
Is characterized by trees that grow fairly fast
like pine trees that needs lots of sun.
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Plant community that no longer undergoes changes
in species composition due to succession.   Hard
woods likeoak maple trees
CLIMAX COMMUNITY