In one example, a program in Hawaii began using discarded fishing nets as an energy source. In order to start this program, what kind of observations needed to be made and how did this program use those observations to know that this plan would work?

Paleontologists have found plant fossils deep within the layers of the north polar region. these leaf fossils have been labeled as to the rock layers they were found in, with the lower numbers being layers close to the earth's surface and higher numbers representing deeper layers. according to the numbers of these four leaf fossils, what might you infer?