Download ecosystem evolution

Ecosystems
Ecosystems are areas where the
abiotic and biotic interact to form a
community of populations
May be large or micro
Each is individual in its
combination of factors
Niche
How an organism obtains its four
needs:

Food, water, space, shelter
Includes breeding and childrearing behavior
Often defined by natural selection
Ecosystem Evolution
Niches within ecosystems are
usually filled
Organisms with the adaptations to
overcome limiting factors survive to
pass on the traits
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Ecosystem Evolution
As time passes, organisms within
the system have evolved
characteristic traits for the system.
Each individual ecosystem is fairly
unique in its evolution
Evolutionary patterns
Two basic patterns of evolution


Generalists
Specialists
Evolutionary Patterns
Generalists



Can tolerate a wide range of
conditions
Seldom need any special condition to
survive
Niche is large and common
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Evolutionary patterns
Specialists



Usually has one narrow tolerance
range
Often needs a special condition to do
well
Often occupies a limited niche
Abiotic Factors
Non-living factors



These factors cause many young to
die before reproductive age.
Adaptations that allow organisms to
survive get passed on and become
common
If the factor is extreme, many
adaptations will evolve to overcome it
Main abiotic factors
2 main abiotic limiting factors


Precipitation
Heat
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Precipitation
Water needed for digestion of
nutrients
Can get too much

Need excretion adaptations
Can be too little

Need to obtain or conserve
Heat
Minimal amount needed to
maintain enzyme function

Need to obtain or slow metabolism
Too much can shut down enzyme
action

Need to cool body down
Lesser abiotic factors
Light



Needed for photosynthesis
Regulate body cycles
Helps form vitamins
Wind


Impact height of plants
Increase impact of temperature
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Lesser abiotic factors
Soil




Particle size determines types of plant
life possible
Nutrient content
Moisture retention
pH
Main biotic factors
2 main biotic limiting factors


Intraspecific competition
Interspecific competition
Interspecific / Food Chains
Obtaining food
•
best to obtain most energy for least
energy expended
• A key herbivore often develops


Key herbivore often fluctuates on a
regular cycle/ prolific reproduction
Predators must evolve strategies to
survive low cycles
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Energy flow
May determine evolution of
hunting/feeding behaviors
Due to limit of energy to
carnivores, most efficient have
advantage

Stalking, pack hunting, ambush,
trapping behaviors evolved
Interspecific / Food Chains
Avoiding predation


Speed, size, camouflage works
Chemicals, herding and mimicry also
used
• These protect the species, not the individual

Early gestation allows for species to
survive high predation rates
Intraspecific Competition
Reduced by avoidance

Eating different foods at different
stages in life / metamorphasis
… by Mom

Parental care tends to bring about
equality among siblings
… by heirarchy

Know your place and be stress free
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Ecosystem Evolution
The final assemblage of organisms
are the result of all of these factors
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