“We could not use the same trick to make food webs circular,” he went on.
So they used another trick, he said. Since all organisms die and decompose, they created a “detritus pool” that all species link to. The pool also links to primary producers in a food web, which make use of the decomposed matter.
Their algorithm differs also in that it determines the relative importance of species through reverse engineering — by seeing which species make the food web collapse fastest if they are removed. The researchers found that the algorithm produces results that were as accurate as much more complex (and computationally costly) software that builds webs from the ground up, simulating evolution.
The next step, Dr. Allesina said, is to refine the algorithm so that it will work with more complex webs. There are many other factors that affect extinctions, including pollution and habitat loss. The goal is to create an algorithm that can take these and other elements into account as well.