Diagrams of interactomes look a bit like webs made by deranged spiders.
Comparing species' interactomes provides another way for scientists to explore the evolution of complex animals beyond just comparing the "parts list" of genes encoded in the genome.
While the interactome encompasses more of an organism's complexity than the genome alone, Stumpf says that comparing interactomes captures only part of the total difference in complexity between species.
That network of interactions, or "interactome," is about 10 times larger than that of the fruit fly and three times the size of the roundworm's interactome.
At least when we score on the basis of interactome size, the humans come out on top" in comparison with fruit flies and roundworms, Bonhoeffer says.