quiz #7 Flashcards
what does it mean for predator/prey to evolve around one another
the traits that are advantageous to predators (stamina, speed, ability to kill prey) and prey (ability to escape predator, speed, etc.) will evolve so that the traits in a population that help either the predator or prey will continue to evolve as it is those species that will reach sexual maturity. These traits mean some animals will succeed (survival to reproduce) versus others will not and beneficial genes/traits will evolve over time.
define territory
area defended by an individual or group. protected areas for nesting, a harem, food
what is trophic cascade? using the example of predator reintroduction into Yellowstone national park in the US, explain how this impacted elements in the biosphere across trophic levels (ecosystem), the lithosphere, hydrosphere and the atmosphere. Focus on specific interactions and outline them clearly as well as giving overall impact.
trophic cascade: when an interaction at one trophic level has effects on other trophic levels. after the removal of wolves in the park, the deers reduced the vegetation to almost nothing. the wolves re-introduction changed the behaviour of the deer (avoided areas of the park they could most easily be trapped like valley). this meant that the bare land started growing and the trees grew higher. this caused birds to move in and the amount of beavers increased. the beavers provided habitats for a variety of amphibians.
define keystone species, what’s the sea otter example?
keystone species: play a crucial role in maintaining ecosystem biotic structure by either preventing other species from taking over an area or allowing other, less competitive species to flourish. sea otters eat sea urchins which protects kelp forests and other species
is a lack of suitable territory a density-dependent or density independent factor?
density dependent
in the short and long term, how does intraspecific competition impact a population?
short-term: density-dependent regulation (territoriality, self-thinning)
long-term: long-term changes as the species adapts to its environment
competitors in the same area must have different what?
niches
define selective pressures. give examples
environmental resistance factors that affect survival and reproduction. ex: predators, parasites, drought, lack of food
define natural selection and biological evolution
natural selection: process of specific traits favouring survival of certain individuals
biological evolution: modification of the gene pool of a species by natural selection over generations
define fitness
features (traits) that adapt an organism for survival and reproduction
a species faced with new selective pressure can do 1 of 3 things
1) adapt: through natural selection
2) migrate: move to an area with suitable conditions
3) go extinct: if the first two options are not possible
which factors determine whether a species can adapt under new conditions?
1) geographical distribution
2) specialization to a given habitat or food supply
3) genetic variation within the population
4) the reproductive rate relative to the rate of environmental change
why are r-select strategists more likely to be successful under stressful environments than k-selected?
for a few of the following reasons the housefly is less vulnerable to rapid environmental change:
1) wide distribution
2) large population
3) high degree of genetic variation
4) small size
5) high biotic potential
6) large number of offspring
7) short generation time
8) ability to migrate
whereas the condor has the following traits:
1) narrow distribution
2) small population
3) limited genetic variation
4) large size
5) low biotic potential
6) small number of offspring
7) long generation time
8) limited ability to migrate
define geographic isolation/how the evolution of new species occurs from it
when the original populations separate into two populations which prevents their genes from mixing. The two separate populations when exposed to different selective pressure will adapt differently. geographic isolation can introduce elements that rapidly lead to an evolution of a different species. for example, the arctic vs gray fox
