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FACTORS AFFECTING DISTRIBUTION OF POPULATIONS
FACTORS AFFECTING DISTRIBUTION OF POPULATIONS
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
- Think about your own tolerance to temperature. For 3 mins, ask your neighbour what you think you would do in -1 degrees, 22 degrees, 30 degrees, and 35+ degrees.
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
2. Acclimation: change in tolerance if change is slow.
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
2. Acclimation: change in tolerance if change is slow.
Same as before, discuss with your neighbour this situation: You have two fish tanks with four fish in each. In one tank you add a tablespoon of salt every day. What would happen?
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
2. Acclimation: change in tolerance if change is slow.
3. Geographical barrier: Simple – the populations can’t get there.
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
2. Acclimation: change in tolerance if change is slow.
3. Geographical barrier: Simple – the populations can’t get there.
Discuss some geographical barriers for populations.
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
2. Acclimation: change in tolerance if change is slow.
3. Geographical barrier: Simple – the populations can’t get there.
4. Leibig’s law: Whatever essential environmental factor is present in the least favourable amount.
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
2. Acclimation: change in tolerance if change is slow.
3. Geographical barrier: Simple – the populations can’t get there.
4. Leibig’s law: Whatever essential environmental factor is present in the least favourable amount.
What could this mean?
Factors affecting the distribution of populations
1. Tolerance: An organism’s ability to survive variation in environmental conditions.
Death / Lower limit of tolerance / Physiological Stress / Optimum / Physiologcial Stress /Upper limit of tolerance / Death
2. Acclimation: change in tolerance if change is slow.3. Geographical barrier: Simple – the populations
can’t get there. 4. Leibig’s law: Whatever essential environmental
factor is present in the least favourable amount. - Eg. Farms around here = cattle got ‘bush sickness’
because they were lacking an essential mineral – cobalt. Now they flourish.
Controls on a population Abiotic -
Controls on a population Abiotic – droughts, fire, flood, storms,
pesticides etc.
Controls on a population Abiotic – droughts, fire, flood, storms,
pesticides etc.Density-independent =
Controls on a population Abiotic – droughts, fire, flood, storms,
pesticides etc.Density-independent = A fire will burn
trees whether there are few or many.Density-dependent = space, water and
substrate where the organism lives. Dependent because
Controls on a population Abiotic – droughts, fire, flood, storms,
pesticides etc.Density-independent = A fire will burn
trees whether there are few or many.Density-dependent = space, water and
substrate where the organism lives. Dependent because if there is a limited amount of space, there will be a limited number of organisms.
Controls on a population Biotic -
Controls on a population Biotic – living influences. Members of
same species, members of another species.
Controls on a population Biotic – living influences. Members of
same species, members of another species.
Density-dependent = hit harder when pop. numbers are high.
Controls on a population Biotic – living influences. Members of
same species, members of another species.
Density-dependent = hit harder when pop. numbers are high.
EG?
Regulating factors What are some regulating facts on a
population?
Regulating factors Competition with species for limited
resource:
Regulating factors Competition with species for limited
resource: same species = same requirements from environment.
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource.
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food:
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity.
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space:
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well.
Regulating factors Competition with species for limited
resource: same species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Regulating factors Competition with species for limited resource: same
species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Not fully understood, but can cause stress syndrome – lack of hormones released when crowded and reproductive organs can shrink and become useless....
Regulating factors Competition with species for limited resource: same
species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Territories:
Regulating factors Competition with species for limited resource: same
species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Territories: Spreads population out.
Regulating factors Competition with species for limited resource: same
species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Territories: Spreads population out. Strongest = best territory.
Regulating factors Competition with species for limited resource: same
species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Territories: Spreads population out. Strongest = best territory. No territory = no mating.
Regulating factors Competition with species for limited resource: same
species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Territories: Spreads population out. Strongest = best territory. No territory = no mating. Heirachies = pecking order – top gets best food, shelter and mates. Ensures best genes mate with best genes.
Regulating factors Competition with species for limited resource: same
species = same requirements from environment. Survival of the fittest – best competitors for resource. This is INTRASPECIFIC competition.
Lack of food: limits re-productivity. EG. Flour beetles become cannibals!
Lack of space: Crowding – plants don’t grow well. EG. Gannets – No space = no breeding that year.
Territories: Spreads population out. Strongest = best territory. No territory = no mating. Heirachies = pecking order – top gets best food, shelter and mates. Ensures best genes mate with best genes.
Regulating Factors Self-poisoning:
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Interesting: Fungi produce penicillin which kills bacteria, but it also slows down the fungi’s growth rate.
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Probably MORE interesting: yeast produce ethanol. However yeast will stop growing when the alcohol reaches 12% (wine). If CO2 is not allowed to escape, the yeasts are poisoned = homemade ginger beer is fizzy, but not very alcoholic.
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Disease:
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Disease: Closer animals are to eachother, easier it is for disease to spread.
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Disease: Closer animals are to eachother, easier it is for disease to spread. Also, high population = more potential for range of disease. (EG. Super bug / human population too big?)
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Disease: Closer animals are to eachother, easier it is for disease to spread. Also, high population = more potential for range of disease.
Parasitism:
Regulating Factors Self-poisoning: bacteria. Wastes
accumulate and kill before the food runs out!
Disease: Closer animals are to eachother, easier it is for disease to spread. Also, high population = more potential for range of disease.
Parasitism: Live off host, but don’t kill them = keep numbers in check.
Competition between dif. species Usually results in
Competition between dif. species Usually results in one population getting
less until it DIES!
Competition between dif. species Usually results in one population getting
less until it DIES! This is all to do with the Gause principle
(we did this a few lessons ago) Predation:
Competition between dif. species Usually results in one population getting
less until it DIES! This is all to do with the Gause principle
(we did this a few lessons ago) Predation: if prey species rise, so do
predator species. Makes sense!
Competition between dif. species Usually results in one population getting
less until it DIES! This is all to do with the Gause principle
(we did this a few lessons ago) Predation: if prey species rise, so do
predator species. More predators = less prey. This in turn lets the prey’s food source to recover (EG – more foxes = less rabbits = more grasses/plants)
Competition between dif. species Usually results in one population getting
less until it DIES! This is all to do with the Gause principle
(we did this a few lessons ago) Predation: if prey species rise, so do
predator species. More predators = less prey. This in turn lets the prey’s food source to recover (EG – more foxes = less rabbits = more grasses/plants) Then, the predators can decrease too if there is less prey.
Competition between dif. species Usually results in one population getting
less until it DIES! This is all to do with the Gause principle
(we did this a few lessons ago) Predation: if prey species rise, so do
predator species. More predators = less prey. This in turn lets the prey’s food source to recover (EG – more foxes = less rabbits = more grasses/plants) Then, the predators can decrease too if there is less prey.
Something to think about In nature, parasites don’t kill their host,
and predators don’t ‘wipe out’ the prey population.
Something to think about In nature, parasites don’t kill their host,
and predators don’t ‘wipe out’ the prey population.
Humans break all the laws when it comes to predator-prey relationships – we hunt things to near extinction (and in the past, actual extinction).
Something to think about In nature, parasites don’t kill their host,
and predators don’t ‘wipe out’ the prey population.
Humans break all the laws when it comes to predator-prey relationships – we hunt things to near extinction (and in the past, actual extinction).
EG. Whaling. There is little or no risk to the humans who hunt whales, yet the whale has certain death.
Something to think about In nature, parasites don’t kill their host,
and predators don’t ‘wipe out’ the prey population.
Humans break all the laws when it comes to predator-prey relationships – we hunt things to near extinction (and in the past, actual extinction).
EG. Whaling. There is little or no risk to the humans who hunt whales, yet the whale has certain death.
How is this fair in the balance of nature?
Emigration Population can be reduced if some of the
animals leave.
Emigration Population can be reduced if some of the
animals leave. May be due to lack of food, crowds, too
much competition.
