Plankton is the organisms that form the base of most open ocean food webs because fish eat plankton and bigger fish like sharks eat the little fish that eats the plankton.
In open ocean food web, the organism that lies at the bottom is planktons. Photo plankton consists of chlorophyll and is able to produce food of its own. The zoo planktons then feed on the photo planktons. Corals also survive by eating planktons. Small fishes survive by eating zooplanktons. Larges fishes then feed on smaller fishes. Thus, plankton is at the base of a complex aquatic food web.
The genetic variations that are best suited for their enviornment
Explanation:
Those that are not well suited for their environment will die off, leaving only the ones that are suited for it. This species will slowly take hold until the species has adapted and become a completely different one.
There are 6 base pair changes between species A and species B. Since we know the rate of change is 1 base pair every 4 million years, we know 6x 4 million is likely how long ago the species diverged. 6x 4 million = 24 million years
