Back in 1981 a book came out – After Man, by Dugal Dixon – that I loved to read in the Geophysical Institute Library. It took as a premise that human beings were extinct, and asked what animals might have evolved to fifty million years in the future. The Discovery Channel, with Dougal Dixon, updated the idea and produced a TV series, now available as a set of 3 DVDs, called The Future is Wild. (It’s also available as a paperback book, but this review is of the DVD set.)

Most of the computer-aided nature videos I’ve reviewed to this point have involved re-creations of extinct animals, from early arthropods to mammoths. With these, we generally have enough fossil evidence to have a pretty good idea of how the animal (or plant) was built. Colors, scales, feather or fur are to some extent guesswork – but increasingly evidence is being found even for these. The movement of these extinct animals is increasingly well understood, in part from animators and paleontologists working together.

What will happen in the future takes a lot more guesswork.

These videos cover three time periods: 5 million years in the future, 100 million years from now, and 200 million years ahead, the last assumed to be 100 million years after a catastrophe has produced a major extinction event.

Some things we can do a reasonable job of predicting. We have a pretty good feel for how the tectonic plates move, and just as we can take that back in time to know what the overall distribution of continents and oceans was in the distant past, we can carry it forward to tell where land, water and mountains will be in the future.

Climate is to some extent determined by the distribution of land and water, so future climates can also be very roughly estimated. One factor not so easy to predict, the amount of greenhouse gasses in the air, is uncertain and remains so.

Further, we have a pretty good idea of how evolution works. The best part of the DVD is the tracing back of the evolution of assumed future creatures using our knowledge of how creatures alive today have evolved.

The actual predicted animals are flights of fancy, constrained by known facts about the adaptations of modern plants and animals. The 5 million year scenario assumes an ice age. The shagrats, for instance, correctly show the reduction of appendages, thick coats and increased size typical of cold-evolved animals. But animals that migrate seasonally must have efficient locomotion, as well. Modern animals able to tolerate and thrive in cold climates include some long-legged types such as caribou and moose, for long-distance travel (caribou) and travel through deep snow (moose) as well as compact creatures such as musk oxen. Granted some of the rather poor locomotion of the shagrats may be attributed to the animation (the original program was produced in 2002) but it still seems to me that features leading to poor locomotion would be selected against.

The other two time periods addressed are 100 thousand and 200 thousand years in the future. In the first, carbon dioxide and oxygen levels are assumed to be very high, leading to a hothouse world with insects much larger than today’s. In the second, after a major extinction event, the continents have all come together to create a supercontinent and a global ocean. Fish are assumed to have evolved into a flying creature, though they are spoken of as extinct even though sharks have survived. Inconsistent. The environments are reasonable; I’m not so sure about the inhabitants.

I also have some doubts about the assumed extinctions. It is certainly true that bears, big cats and wolves are under threat today – but the threat is primarily from human activities. The starting point for this assumed evolution, especially in the 5 million year scenario, is critically dependent on how and when humans become extinct, but this is never addressed. Still less is the extinction of entire large clades, such as the mammals. This has rarely happened in the past. Even the dinosaurs are still with us, as birds. Mammals may well evolve into something quite different, but it seems unlikely to me that the strategy of high investment in young and feeding them through special glands will become extinct.

The DVD is worth watching for its insights on how evolution works and some of the more interesting and bizarre relationships it has produced today, as well as the geography and weather patterns of the future. But don’t take the future life-forms too seriously.