Ecosystems

1
Ecosystems
Interactions among living things
2
Natural Selection

• A process by which characteristics that make an
  individual better suited to it's environment
  become more common in the species.
• Sometimes referred to as survival of the fittest

3
How Does Natural Selection work?

• Those with the unique characteristics best suited
  for their environment will survive and produce
  offspring.
• End result ADAPTATIONS

4
English Peppered Moth Natural selection in action
dark moth - random mutation not as common
Soot covered tree England 1800s
camouflaged moth
5
Adaptations

• Behaviors or physical characteristics that allow
  organisms to live successfully in their
  environment

Shell for protection
Long neck to reach leaves
Long shallow roots, needles to protect from
animals
6
Niche

• An organisms role in an ecosystem niche.
• Niche and Habitat are different
• Address of an organism Habitat
• Job or Profession Niche

Organism tree
Habitat Forest
Niche produce oxygen provide home
for birds
7
Explain why two organisms cannot occupy the same
niche

• If two species occupy the exact same niche in
  nature, one will die off due to competition for
  limited resources.

8
Video Link Niche, Competition, Predation, and
Symbiosis
http//www.youtube.com/watch?vD1aRSeT-mQE
9
Three major types of interactions among organisms

• Competition
• Predation
• Symbiosis

10
Competition

• The struggle between organisms to survive as they
  attempt to use the same limited resources.

11
Predation

• An interaction in which one organism kills
  another for food.

12
Predator or Prey

• Predator - organism that does the killing
• Prey organism that is killed.

13
Effect of predation on population size

• What variable is plotted on the x-axis?
  ______
• What two variables are plotted on the y-axis?
  ________ and __________

years
of moose
of wolves
14
Effect of predation on population size

• How did the moose population change between 1965
  and 1972 ___________
• How did the wolf population change between 1973
  and 1976? __________

It increased
It increased
15
Effect of predation on population size

• How might the change in moose population have
  lead to the change in wolf population?
• The wolf preys on the moose so more moose meant
  more food for the wolf.

16
Effect of predation on population size

• How might disease in the wolf population one year
  affect the moose population the next year?
• Disease in the wolf population might cause some
  to die. With less predators, the moose population
  would most likely increase.

17
Examples of Predator Adaptations

• Cheetah speed
• Owl eyes
• Jelly fish venom

18
Defense Strategies of Prey

• Mimicry
• Protective Covering
• False Coloring
• Warning color
• Camouflage

19
Video Link on Predator and Prey Interactions
http//www.youtube.com/watch?vvZynrBA91fY
20
Interactions Three Types
21
Symbiosis a close relationship in nature that
benefits at least one species
Bacteria from gut of termite
Termites
22
Symbiosis
23
Mutualism

• Both species benefit

24
Commensalism

• One species benefits, but the other isnt harmed
  or helped.

25
Parasitism

• One species benefits and the other is harmed.
• The one benefiting is the parasite
• The one being harmed is a host