“A world without rodents would be a very different world. It is less likely to come to pass than a world dominated by rodents and free of people. If nuclear war destroys humanity and most of the rest of life, a good bet for survival in the short term, and for evolutionary ancestry in the long term, is rats. I have a post-Armageddon vision. We and all other large animals are gone. Rodents emerge as the ultimate post-human scavengers. They gnaw their way through New York, London and Tokyo, digesting spilled larders, ghost supermarkets and human corpses and turning them into new generations of rats and mice, whose racing populations explode out of the cities and into the countryside. When all the relics of human profligacy are eaten, populations crash again, and the rodents turn on each other, and on the cockroaches scavenging with them. In a period of intense competition, short generations perhaps with radioactivity enhanced mutation-rates boost rapid evolution. With human ships and planes gone, islands become islands again, with local populations isolated save for occasional lucky raftings: ideal conditions for evolutionary divergence. Within 5 million years, a whole range of new species replace the ones we know. Herds of giant grazing rats are stalked by sabre-toothed predatory rats.* Given enough time, will a species of intelligent, cultivated rats emerge? Will rodent historians and scientists eventually organise careful archaeological digs (gnaws?) through the strata of our long-compacted cities, and reconstruct the peculiar and temporarily tragic circumstances that gave ratkind its big break?”
From The Ancestor’s Tale by Richard Dawkins. It’s a great read.
*Dougal Dixon long ago foresaw this, and he had the talent to paint it, in his imaginative book After Man: A Zoology of the Future.”
After Man: A Zoology of the Future
Dixon he presents his hypothesis on how the fauna and geography could change 50 million years from now.
While there are a wide variety of creatures in After Man, many of these can fall into easily recognizable groups, e.g. rabbucks, gigantelopes, predator rats, etc. Some of the larger groups in the future include…
Rabbucks – Rabbucks are the future equivalent of deer and antelope but descended, as the name suggests, from rabbits. They live in almost any environment, and they mostly feed on grass. Their anatomy resembles that of a hooved mammals, though there are a few primitive hopping forms lurking around.
Gigantelope – The gigantelope take the niche in the future that was formerly held by elephants, giraffes, moose, and other large herbivores. Resembling the ancient sauropods, they are descended from antelopes, and range in a wide variety of forms. One subbranch have evolved into the large, moose-like herbivores of the north, the hornheads.
Predator Rats - The major group of predators in the future. Like our modern carnivorans, they exist on almost every continent and fill almost every carnivorous niche. They evovled, as the name suggests,from rats, and range in forms resembling polar bears, wolves, wolverines, cats, and even aquatic walrus-like forms.
Carnivorans – For the most part, Dixon assumes that carnivorans have either gone extinct, or have been forced into peripheral niches like the creodonts were in the Oligocene. A few still exist, such as the shurrack, and all but one, the striger, is descended from cats.