Okay. I have officially heard it all. Microbiology and archaeology combine to retrace lost Roman roads.
I know. I was skeptical too. Well, here's basically how it works/tracks back to Roman times. Molds want to find food via the shortest path between points A and B. So, they meander (slime along) until they get to the food (a flake of oatmeal). The odd thing is that when food was placed in roughly the places (on agar in a petri dish) as 17 towns and major cities of the ancient Roman empire, the slime mold traveled the same route as the Roman roads. Researchers found this to be true of known (and still used) roads as well as military roads only described in ancient travel texts. Interesting! So next time I need directions, I might try a trusty slime mold. It would take days, but all for the advancement of science, I say!