Energy nurence and viamins ar the thigs that cone frome it
D. high and low levels of silica in the different type of lava.
Explanation:
The volcanoes have different types of explosions. Some tend to be highly explosive, some less explosive, some don't have explosions at all, while some have combinations of different eruptions. The reason for this diversity in the eruption types is mostly the composition of the magma, or rather how high is the silica content in it.
Basically, the higher the silica level in the magma the higher the explosiveness, and the lower the silica level the lower the chances of explosiveness. This is the case because the higher amount of silica makes the magma thicker, so the gasses are trapped and they explode, while when the lower silica content makes the magma less thick, so the gasses are not trapped and explosions are lacking.
Because gm crops can't replace everything. yes even they can make a better species and increase the productivity, but some countries or farmers might not have the technology to replace all the crops with gm crops, and they still have to rely on chemical fertilisers. chemical fertilisers can be deadly as if u overuse them, it can pollute the water and leading to euthrophication, where it can kill sea animals
Geographic information systam
its like a scan of the earth
They could adapt to live together so that for example one starts eating only seaweed while the other starts eating only organic matter so they don't compete for food. They could also adapt like when squirrels are separated into those who eat on trees and those who eat on the ground. The 2 urchin types could split into those who eat of the ground and those that eat what floats and drifts.