Download document 4386316

Weeks 5,6,7 Of Independent Study-Section 14.4
By: Prubleen Matharu
Definitions:
Community: All populations in a given ecosystem at a given time
Ecological Niche: An organism’s biological characteristics, including use of and
interaction with abiotic and biotic resources in the environment
Fundamental Niche: The biological characteristics of the organism and the set of
resources individuals in the population are theoretically capable of using under ideal
conditions
Interspecific Competition: Interactions between individuals of different species for an
essential common resource that is in limited supply
Realized Niche: The biological characteristic of the organism and the resources
individuals in a population actually use under the prevailing environmental conditions
Symbiosis: Various interactions in which two species maintain a close, usually
physical, association: includes parasitism, mutualism, and commensalism
Interference Competition: Interspecific competition that involves aggression between
individuals of different species who fight over the same resource(s)
Exploitative Competition: Interspecific competition that involves consumption of
shared resoures by individuals of different species, where consumption by one species
may limit resource availability to other species
Resource Partitioning: Avoidance of, or reduction, competition for similar resources by
individuals of different species occupying different non-overlapping ecological niches
Mutualism: A symbiotic relationship in which both organisms benefit; as neither is
harmed, it is categorized as a +/+ relationship
Commensalism: A symbiotic relationship in which one organism benefits and the other
organism is unaffected; it is categorized as a +/o relationship
Parasitism: A symbiotic relationship in which one organism (the parasite) benefits at
the expense of another organism (the host), which is often harmed but usually not killed;
it is categorized as a +/- relationship
Obligatory Mutualism: A symbiotic relationship in which neither species involved could
survive without the other
Microparasites: Parasites, such as plasmodia or trypanosomes, that are too small so
see with the naked eye
Macroparasites: Larger parasites, such as tapeworms, fleas, and ticks that are readily
visible
Endoparasites: Parasites that live and feed within the host’s body
Ectoparasites: Parasites that live and feed on the outside surface of the host, such as
lice, ticks, and parasitic mites
Social Parasites: Parasites that complete their life cycle by manipulating the social
behaviour of their hosts
Study Notes
Some organisms within communities cannot exist independently of one another and
work together to survive (e.g pollination by insects for flowers)
Ecological Niches
Animals can either adapt constantly to changes in their community or survive by
occupying an ecological niche. The African lion’s ecological niche, for example, includes
what it eats, what eats it, the way it reproduces, its habitat, etc that describes its pattern
of living. Ideally, if resources were abundant and there was no competition with other
species they would come close to occupying its fundamental niche. In reality they face
interspecific competition with vultures and hyenas for similar resources and occupies
only a portion of its fundamental niche, what ecologists call realized niche. As an
example you are capable of becoming captain (fundamental), but competition from
others actually make you assistance captain (realized).
Classification of Interactions Between Two Species
Interaction
Competition
Predation
Symbiosis
Parasitism
Mutualism
Commensalism
Effect on Population
Interaction may be detrimental to one or both
species
Interaction is beneficial to one species and
usually lethal to the other
Interaction is beneficial to one species, and
harmful but not usually fatal to the other
Interaction is beneficial to both species
Interaction is beneficial to one species and the
other species is unaffected
Interspecific Competition
 Occurs between individuals of different populations (serves to restrict population
growth)
 Can occur in two ways
o Interference competition is actual fighting over resources (e.g birds
fighting over a birdhouse)
o The consumption of use of shared resources is called exploitative
competition (e.g both Arctic foxes and Snowy owls prey on the population
of Arctic hares)
 The greater the niches that overlap, the greater the competition
 Gause’s principle (competitive exclusion) states that if resources are limited, no
two species can remain in competition for exactly the same niche indifenititely
 Population of weaker competitor could decline
 Change in behaviour to survive
 Migration into another habitat to survive
 Resource partitioning-to minimize competition for food (lizards use various parts
of the trees)
 Competitors force species to evolve
Predation
 Interspecific interaction in which the population density of one species-the
predator-increases while the population density of the other species-the preydeclines
A model of the
predator-prey
cycle. Because of
the oscillations in
the populations,
the line in this
graph is referred
to as a sinusoidal
curve
Selected Results from Kreb’s Lynx-Hare Cycling Study
Plot Characteristics
Result
Plot 1
Predator Free
Hare density doubled
Plot 2
Extra Food
Hare density tripled
Plot 3
Predator reduction and
extra food
Hare density increased
eleven-fold (1100%)
Defence Mechanisms
 Plants use:
o Morphological defences (thorns, hooks, spikes etc.)
o Chemical defences against herbivores (e.g Blue Jay’s regurgitate
Monarch butterflies because of the toxins consumed from Milkweed
plants)
 Passive defence (hiding)
 Active defence (fleeing, more costly in terms of energy)
 Animals use : alarm calls, cryptic colouration (camouflage), visual warnings
 Mimicry:
o Batesian-a palatable or harmless species mimics an unpalatable or
harmful species (moths, butterflies)
o Mullerian-animal species that resemble one another and are all
poisonous or dangerous
Symbiosis (“living together”)
 Three different types: mutualism, commensalism, and parasitism
Mutualism
 Both organisms benefit
 Obligatory mutualism-where both species need each other to survive
Commensalism
 When a species benefits from another species while the other species is
unaffected
Parasitism
 ¼ animal species may be parasites
 Microparasites-microscopic in size with a rapid production rate
 Macroparasites-larger organisms, such as tapeworms, fleas, and lice
 Endoparasites-organisms that live inside the body of their hosts
 Ectoparasites-organisms that live and feed on the outside surface of their
host
 Social parasites-manipulate the social behaviour of another species so that
they can complete their life cycle
Disruption of Community Equilibrium
 Stability in biological communities exists when the resources necessary for
survival are sustained, populations do not exceed their environment’s carrying
capacity, and interspecific interactions contribute to biodiversity
 A variety of disturbances can affect this equilibrium such as a natural disaster,
the introduction of exotic (non-indigenous species)
Case Study: The Struggle for Survival Pg.678
1) In the first experiment it can be seen that the species that wins over the other
species reaches the density that it would, if grown independently. In Gause’s
second experiment if is seen that the growth of the two species together
benefitted one species while the second one appeared unaffected and
maintained the same population density as before. Therefore, it doesn’t appear
as to which ones grown separately or together, but rather which ones species are
grown together.
2)
Species
Alone
P. caudatum
P. aurelia
P. bursaria
125
155
35
With P.
caudatum
N/A
165
35
With P.
aurelia
45
N/A
N/A
With P.
bursaria
70
N/A
N/A
3) This statement is true because it demonstrates how both species relied on the
same resource which was the yeast, as both species shared their resource.
4) A theory as to why both paramecium survived is on how they reacted together,
and more of how their relationship was. My theory is that these two species
shared a symbiotic relationship either with each other, or with other organisms,
where P. caudatum appeared to benefit while P. bursaria appeared to be
unaffected. This symbiotic relationship is called commensalism and is relevant in
terms of these two species together, or with other organisms.
5) After researching the diet of each paramecium it can be found that the data
matches the experimental results. First, paramecium use their cilia to sweep food
they find into their oral groove, which is what P. caudatum and P. Aurelia both
do. They both rely on yeast or algae as their food source and physically eat it
which explains why one paramecium beat out the other, as it was exploitative
competition. In the second experiment, P. bursaria was found to have a symbiotic
relationship with a green algae called Chlorella. Because of this relationship P.
bursaria gets food from Chlorella and in turn provides a warm and safe
environment for the Chlorella. Therefore the paramecium in which had a
beneficial symbiotic relationship was not affected by other paramecium because
they didn’t have competition over the same food source. The paramecium that
share the same food source can only have one successful population.
Try This: Finding a Host Pg.686
Chosen endoparasite: Tapeworms
Explore an Issue: Profile of an Exotic Invader Pg. 687
a) The species that I have chosen is the West African bat. The West African bat
naturally preys on insects and small animals. This could cause the populations of
many insects to decrease which may have a domino effect on the other plants
and organisms that rely on those insects. This would also create interspecific
competition between other animals that prey at night and eat insects.
b) If this species was to be introduced, it would cause the government a lot of
money to be able to remove the whole species. Bat’s are also known to carry
diseases, as such in the recent outbreak of Ebola may have been linked to one
of these bat species, and could be detrimental to not just us humans, but to other
animals as well.
c) Some strategies and/or technologies include:
 Trapping
 Reducing resources
 Poison/chemical use
 Introduction of a natural predator to the invasive species
d)
Attention to the Canadian public! There has been new information of an invasive
species of bats somewhere in this area. The species of bats are the West African Bat.
This species of bats are larger compared to the bats that us Canadians are used to and
they may pose a threat to our ecosystems here in the North. The bats usually prey at
night and eat insects and small animals. These bats are not known to carry diseases,
however due to the recent Ebola outbreak there has been many links to this species of
bats and the virus. You are cautioned to not touch, feed, or house these animals as it is
unclear of how destructive they can be to our ecosystems around us and to our health.
These bats are also commonly called Fruit Bats. Below is a picture of what these bats
look like. If a bat is found please contact your local pest control authourities.
Section 14.4 Questions Pg. 688
1)
a)
b)
c)
d)
Exploitative (rely on the same resource)
Interference (actual fighting and killing of another species)
Interference (species physically fight off each other)
Exploitative (rely on the same resource)
2) Naturally, Balanus balanoides grow on the lower portion of the rocks on the shore
and Chthamalus stellatus on the lower portions. When the Balanus were removed from
the lower portions the Chthamalus were seen to be able to grow on the lower portions,
This means that out of the two species competing, it was Balanus that out competed
Chthamalus. The way things are in natural conditions is the realized niche where
Chthamalus could have a larger population number but the Balanus are competing with
resources so they are not reaching their potential. When the Balanus are removed, the
Chthamalus reach their fundamental niche because they can grow more freely without
competition and fully reach their actual potential.
3) Since the Mussels and Pisaster live together because their niches overlap, there is a
need for more or greater resources of different types for these two species to live
together. We can compare this to when they are alone as they don’t need as many
resources, but when they are together it indicates that the area is able to sustain both
species needs. The larger the amount and variety of resources, the more advantageous
it becomes for other species that may also use the same resources.
4) These two species are in interference and exploitative competition with each other
and adapt physically to their environment to survive. The two species may have had the
same food resource as each other, so the species had to adapt to their environment
and take on competition. The finch with the larger bill size may have adapted to be able
to reach insects further in trees and in the ground. Since this adaptation was in favour of
the finch, they passed on their genes to their offspring. Similarly with the short billed
finches who were also able to survive and pass down their genes. The reason why this
didn’t happen on the other islands was because there was no competition over the
same resource.
5)
a) Camouflage
b) Chemical
6) Predation is when one species captures, kills, and eats another species to survive.
Parasitism is when one species inhibits another species and survives off of their
nutrients and environment. These two are different because parasites use their host as
a food source and shelter and usually live inside of a host as long as possible where
predation is a temporary solution to hunger.
7) Obligatory Mutualism
Lab Exercise 14.4.1 Pg. 691
a) If wolves are introduced and naturally hunt deer, then the deer population will
decrease.
Changes in White-Tailed Deer and Wolf
Populations
Population Numbers
3000
2500
2000
1500
Series1
WhiteTailed Deer
1000
Series2
Wolves
500
0
1988
1990
1992
1994
1996
1998
2000
Years
b) In this situation the wolves are a limiting factor. This is because the wolves prey
on deer which lowers theirs numbers and cause other animals that may rely on
the deer to suffer. The wolves limit the growth of the organisms living in the forest
reserve directly or indirectly.
c) Some other factors that may limit the deer population include:
 Limited resources
 Disease
 Interspecific competition
 Natural disasters
d) As the density of the deer population increases, so does the wolf population. This
is because the wolves’ food source has increased in numbers making them more
readily available and easier to hunt. More wolves survive this way and reproduce
causing their population to increase.
e) Before the harp seals are unnecessarily killed we must first determine the root
cause for this populations decline. One thing we can do is determine the fishing
areas where there is the least amount of cod, and see if there is any relationship
between the fishing happening there compared to where the cod aren’t fished as
often. This will help us know if it is the fishing that is causing the cod population
to decrease. Another thing that can be done would be the same process, but with
the equipment and compare it to other sites that don’t use equipment. Then as a
final resort we can see how the harp seals interact with the cod and the amount
of damage that is really done. If it is the harp seals then they could be moved to a
different location or could be waited out since their population will decrease
anyways due to the decrease in their food source population.
Works Cited
https://www.ebiomedia.com/the-biology-classics-paramecium-diet.html
http://101science.com/paramecium.htm
http://www.open.edu/openlearnworks/mod/oucontent/view.php?id=198&printable=1
http://www.nbcnews.com/storyline/ebola-virus-outbreak/where-did-ebola-come-likelyone-person-gene-study-finds-n191161
http://www.open.edu/openlearnworks/mod/oucontent/view.php?id=198&printable=1
http://www.nbcnews.com/storyline/ebola-virus-outbreak/20-20-hindsight-doc-who-sentebola-patient-home-says-n263446
http://www.pri.org/stories/2014-08-13/ebola-crisis-rages-west-african-villagers-arewarned-away-fruit-bats
http://www.livescience.com/47946-where-did-ebola-come-from.html
http://www.2ndchance.info/tapeworm-cyclicimageLgfl.htm
http://www.nwf.org/what-we-do/protect-wildlife/invasive-species.aspx
http://www.hispanicallyspeakingnews.com/latino-daily-news/details/food-andagriculture-organization-warns-of-link-between-ebola-eating-fruit-/30606/