Flashcards in Exam Notes - Questions Deck (25)
How does the principle of allocation apply to the transgenic super mice example?
- doubling the growth of the mice reduced resources to other features
- mice ate less, stopped reproducing, slept more, caught more diseases, and didn't live as long
What trend do we see in a populations of high density?
- natural selection favours adaptations that enhance survival and reproduction with few resources
What trend do we see in populations of low density?
- natural selection favous adaptations that enhance rapid and elevated rates of reproduction
What kinds of growth pyramid can be seen in a population?
- rapid growth
- slow growth
- zero growth/decrease
Why do the Cthamalus barnacles have a different fundamental niche and realized niche?
- they are outcompeted by the balanus barnacles
- they are forced to the very top of the rock face (aka the top of their fundamental niche), because the balanus can't live there
What is an example of Batesian Mimicry?
- wasp beetles mimicing wasp colouring to seem more dangerous than they really are
What is an example of an inducible defence?
- mussels allocate more resources to shell strength and attachment to rock faces when there are predators around
What happens when a keystone predators is removed from it's ecosystem?
- the organisms that used to be prey for the predator grow in abundance
- this organism may outcompete other organisms in the area and reduce the biodiversity
What did Sousa test in his rock experiment? What were his findings?
- how disturbances affect an environment
- specifically how disturbances to a rock affect the intertidal plants and animals who affix to that rock
- found that intermediate amounts of disturbance had the greatest biodiversity over rarely disturbed rocks and often disturbed rocks (intermediate disturbance hypothesis)
Why is the idea of a climax community flawed?
- no area is truly stable, there will always be some amount of disturbance
- mature communities are more complex and always changing
What features that affect population might be found on a bigger, closer island over a smaller, farther island?
- higher immigration
- shorter distance for colonizers to travel
- lower extinction
- more resources
- more diverse habitat to be partitioned
What are some negative impacts that humans have on the ecosystem?
- oil spills
- poor logging practices
Who was Rachel Carson?
- journalist, advocate for biologist
- wrote "Silent Spring"
- exposed effects of DDT on the environment and helped get it banned in North America
What are some indicators that we have overshot the Earth's carrying capacity?
- decrease in vital ecosystems
- decrease in non-renewable resources
- ozone depletion
- climate change
- biodiversity loss
- fisheries collapse
What are similarities and differences between the expansionist perspective and the steady-state perspective?
- they both focus on a growing economy as something that is good
- expansionist sees the environment as being infinite, steady-state sees the environment as finite
- expansionist dumps waste, steady-state recycles
What are the goals of conservation biology?
- to offset the biodiversity crisis
- to preserve indivudual species
- to sustain ecosystems
- to maintain genetic variability
What often happens to small populations?
- small populations lead to inbreeding and random genetic drift
- leads to loss of genetic variability
- reduces individual fitness and population adaptability
- leads to lower reproduction and higher mortality
- leads to an even smaller population
What are some values of biodiversity?
- commercial value
- recreational and aesthetic value
- scientific value
- intrinsic value
What are the causes of extinction?
- habitat destruction
- habitat fragmentation
- introduction of exotic species
- overexploitation of resources
- disruption of food chains
- global warming
What did various researchers find on easter island?
- Flenley and King: used that pollen samples to discover that there was less palm tree pollen at the time that settlers arrived
- Steadman: island fauna had changed
- Diamond: discovered that the settlers caused deforestation, which led to soil erosion and a lack of trees for fishing canoes
What were some lessons learned from the Tragedy of the Commons?
- overuse and exploitation of the natural vegetation by having so many cattle caused soil erosion when it rained
What are some obstacles with commons?
- they are difficult to protect since there is no direct owner
- no one wants to assist with costs
- resources are not monitored effectively
What are some of the goals for wild life corridors?
- allow for recolonization
- allows for gene flow
- introduces new alleles that would possibly counteract deleterious effects of inbreeding or genetic drift
What is one example of a sustainable operation?
- collin's pine company
- family-owned logging company
- tree planting and selective logging allow them to continuously replenish their resources