Lecture 9-10 Mutualism and Symbiosis Flashcards
What Is Symbiosis?
Symbiosis is when organisms live together
what is mutualism
Mutualism when species live together in a mutually beneficial relationship
How does mutualism and symbiosis differ?
For organisms to engage in a mutualistic relationship, both species must be benefiting the other in some way that is usually related to food and resources
What are the different types of reciprocal change
Nutritional, Defensive, and dispersal
Nutritional Mutualism
When species get food or shelter from a plant, that plant will receive nutrients from the organism
Defensive Mutualism
Exchange of protection for food
Dispersal mutualism
Plants and animals will exchange seed dispersal for food. So the animals will eat the food from plants, expel them with seeds and the seeds will flower
Invasional Meltdown
This is when 2 non native species facilitate mutualism and propel each other’s growth
What is Reciprocal Adaptation?
Give an example
Reciprocal Adaptation includes two species that have specific traits that seem to fit together, and this match will facilitate an evolutionary growth with each other and benefit each other’s fitness
An example is Darwin’s Orchid where this orchid has a very narrow path and in order for it to be pollinated it requires an insect wit a vary long and narrow sucking tube.
Mutualist Networks
Mutualist networks explain that mutualist relationships are strictly tied to 2 species alone, in most cases 2 species will benefit each other, which benefit others. New generations will produce new partners to form mutualist interactions, known as horizontal transmission
Microbiomes
All the microbes living in a community
Dispersal
Species moving out to a new area nearby
What are the benefits of dispersal
- avoid competition
- avoid in breeding
-colonize new areas
Metapopulation
Spatially distinct populations that are connected through dispersal
What is a patch? How does it relate to metapopulations?
A patch is a distinct population in a metapopulation
What is the benefit of metapopulations in terms of avoiding or recovering from extinctions
If a patch goes extinct, it can be locally repopulated by neighbouring patches
How can metapopulations allow for species co-existence
When predators and prey exist in unstable communities where they are quickly being killed off because of resource limitation, the solution usually involves in pairing these numbers so they can form a stable communities, through dispersal
What is involved in patch dynamics?
Patch dynamics looks at patch occupancy over time.
in patch occupancy, we look at the colonization, which is affected by the fraction of average occupied patches, P and the fraction of empty patches, 1-P
What is the model of Levin’s Patch occupancy? Explain each variable.
dP/dT= cP(1-P)-eP
c= constant
P=Patches
1-P= fraction of empty patches
e= constant that relates the rate at which patches go extinct
What does global co-existence require?
Species A must be better at dispersing, or a faster disperser
Species B must always outcompete them
This is a competition-colonization trade-off
Example of a metapopulation
Pikas are an example of a metapopulation because they have a varying occupancy in different patches and a source sink pattern
What are the different ways a population can be driven to extinction?
competitive exclusion
predator-prey interactions
Allee effect at low tendencies
stochasticity fluctuations in population numbers
How are these tendencies countered
Predation through preventing competitive exclusion
variation in life-history trade-off, competition colonization
What is a Metacommunity and how does it differ from a metapopulation
metacommunity is a set of local communities that are linked through the dispersal of local species.
This is different from metapopulation because the latter is spatially distinct population linked through dispersal
What determines the number of species on an island
colonization
extinction
in-situ speciation
What is the goal of the theory of island biogeography?
Predict the population of a species by looking at the island’s size and isolation
MacArthur and Wilson only considered colonization and extinction
What is the difference in the equilibrium value at a far and near island
Sn>Sf
What is the difference in equilibrium value at a small and large island?
Sl>Ss
For all types of island, list equilibrium value in terms of largest to smallest
Snl>Sns>Sfl>Sfs
How does habitat size and isolation affect species richness
Habitat size decreases with isolation and increases with are
Species richness will be very small if habitat size decreases with isolation
