Which statement best describes an ecosystem
maintaining a state of approximate equilibrium?
(1) nutrients from decayed organisms are
recycled in a forest ecosystem.
(2) all the frog species in a south american rain
forest become extinct.
(3) a mutation spreads through a species of
bacterium, making them unable to decompose
wastes.
(4) mice are released into a field ecosystem as
food for a declining predator population.