Pg. 235 chap 12 questions
What is metapopulations:
-set of subpopulations that are connected by dispersal or movements in and out of the region
- there is always a core population where dispersal is the highest and emigration and it has the
lowest risk of extinction
- metapopulation as a whole never changes but minor changes in sub pop.
-metapopulations has 4 conditions:
1. Suitable habitat that OCCURS in discrete patches:- it has to be large enough to support
2. Subpopulation cannot be too isolated
3. Every subpopulation is substantially at risk of extinction ( including the largest subpop)
4.dynamics of subpopulation is not synchronized otherwise it will be one big pop
if one pop goes extinct then it gets recolonized by a diff..ind of diff populations move into that
- if the immigration rate is high they wont distinct they will be function as one continuous
- the immigration rate shows how different they are, how discrete they are…the lower it is the
more discrete they are the higher the more synchronized they are
if no ind is coming to repopulation/recolonization that its going to die out
4. the distance btw metapop it affects the rate of colonization if ur really far apart your less likely
to get colonized
- the closer they are the higher the probability of colonization and the lower the chance of
extinction while the further apart they are higher the chance of extinction and lower rate of
5. means each habitat is different population dynamics is different…different species but similar
enough to recolonize each other they can reproduce but different enough to be defined.
If you have a large patch compared to small patch…forest fire in small patch will destroy
-everyone is ind in local pop then extinction ate increase because they are not together they are
independent…they are not depending on one another.
if you have rabbits and one of them live in desert vs forest…if the forest goes on fire it doesn’t
affect the one in desert so they go and recolonize it.
-role of immigration in maintain the persistence of local pop that would otherwise go extinct has been termed as the rescue effect.
7. Source population= individuals moving out this population offers more resources and more
individuals are colonizing it…the sink population does not offer much resources
8. source habitat would be better thant he sink because the source is where the growth rate is
higher than the sink…
9. weather patterns- etc…look at the summary
1.Amensalim= neutral for one and bad for the other.Taller trees growing over the smaller trees…
if the tree was already grown
- competition is when they are both negatively affected but the other one, one is neutral and the
other is negatively affected
2. little fishes eating off the shark (commensalism example)
mutualism= they both benefit
- remove the other organism and observe whether its still neutral or not etc
3. if there aren’t predators they are going to overpopulate and take out all the resources
- deer: if you have the predator it controls the population—its still growing but logistically instead
4.if there is no –ve interaction then that means their relative fitness will decrease because they
don’t need to adapt to anything anymore they just maintain themselves ( they are perfect) eg.
humans we are degrading—eating candies= damaging + we are getting fatter.
5.No, if you have randomly ppl being killed for prey- the phenotypic is going to be same no
- natural selection favors one thing over the other
6.the prey only got it evolved to hide from the predator
- coevolution joint