Non perishable food is the answer to this
Answer:
You first kill/dominate the other and then you dictate whatever is left.....
Try, Dinosaurs, birds. fish, reptiles. amphibians.
I believe the biosphere is fragile, because over time all of the pollution us humans have made; If its from air pulloution, acid rain or even water pollution. the toxic acids over time have made the biosphere and the ozon layer weaker and more thin. which causes the biosphere to become weaker.