Differences in the relative abundance of different species in a community result from (choose any/all that apply, points deducted for incorrect answers):
a. variation in dispersal
b. time since last disturbance
c. predation and disease
d. differential reproduction rates
e. differential survival rates
f. variation in competitive ability to capture a particular resource
g. random effects

Which of the following is true about the introduction of a non-native species to an environment? (a) they usually adapt quickly so they can have a positive affect on the environment. (b) they can disrupt the environment and cause much damage and devastation to native species. (c) they usually become predators in a food chain and to keep prey populations under control. (d) because the native species are better-adapted to the environment, the non-native species always end up dying out.