“…This, however, contradicts Gause's classic observation of mutual extinction in the protozoans, Paramecium and its predator Didinium (Gause(1934), Luckinbill(1973), Abrams and Ginzburg(2000)), and the well cited experimental observation of Huffaker (Huffaker(1958)). Until very recently, both ecologists and mathematicians chose to ignore the rich dynamics provided by the strict ratio-dependent models, especially that on the boundary and close to the origin (the origin is a singular equilibrium, which renders direct local stability analysis impossible).…”