- The Observer, Sunday November 11 2001
The beast waits patiently for several hours. Then a small forest creature, the size of a cat, comes to the water's edge. The predator springs from the depths, seizing its prey in its heavily toothed jaws and dragging it underwater.
The killer is ambulocetus, an ancestor of the whale. It ruled our planet 50 million years ago, and this week BBC1 viewers will be able to see how it lived when ambulocetus is resurrected in the first episode of Walking with Beasts - thanks to the skills of computer animation experts.
It makes gripping and highly controversial viewing - for just as the series' predecessor, the phenomenally successfully Walking with Dinosaurs, enmeshed its makers in accusations of deliberately blurring fact with fiction, so the new programmes have provoked claims that producers have sacrificed truth on the altar of drama.
Walking with Beasts follows the rise of mammals, from squeaky dinosaur food to rulers of the Earth. In it, species are depicted in different hues, though no evidence of their colour remains; actions of animals are interpreted in terms of modern creatures, although tens of millions of years of evolution separate them; while other prehistoric behaviour is extrapolated from a few pieces of fossil bone.
Yet many scenes have infuriated academics who believe Walking with Beasts contains dangerous distortions. 'We are turning science into a sort feeder industry for Jurassic Park,' said British palaeontologist Professor Michael Coates, now based at Chicago University. 'We are trivialising it and making claims for which there is no evidence.'
The series' experts argue that their assumptions are reasonable. 'In the case of ambulocetus, we know it is very similar to the modern crocodile. It catches its prey by snatching animals from the riverbank and it kills by drowning its victims,' said Professor Neill Alexander, of Leeds University. 'It is perfectly reasonable to assume ambulocetus did the same.'
The trouble is that the programme does not acknowledge the fact these depictions are based on assumptions. 'This is drama presented as documentary,' palaeontologist Professor Leslie Aiello, of University College London, said. 'All the animals have been given coloured coats, for example. It would have looked funny if they hadn't. But at no point do the makers admit they had to guess each colour - for there is simply no fossil evidence to provide any supporting evidence. Instead they pass it off as fact.'
Scientists such as Aiello believe a short documentary - providing support for each assumption made in the programmes - should have been screened as a closing item, in the style of the mini-documentaries presented at the end of each of the recent, acclaimed natural history programmes in the Blue Planet series.
However, the producers of Walking with Beasts claim they have done this. 'Viewers of digital TV will be able to watch all sorts of additional features about the evidence we used to make the programme,' said series producer Jasper James. 'They can see exactly what assumptions we have made.' But most viewers will simply see Walking with Beasts with its assumptions presented as facts. 'I don't think that is necessarily terrible,' said palaeontologist Dr Adrian Lister. 'You have to have some guesswork or you won't get anywhere.'
The real issue is: how much guesswork do you accept, and admit to, and how much fiddling with images to improve drama is acceptable?
'This sort of programme represents the thin end of a wedge,' Sir David Attenborough admits. 'We really need a code of conduct for making nature programmes in future. You don't want to break the spell of a documentary, but you do have to be honest about how you filmed something. We now have the ability to change images to suit our purposes, thanks to digital technology, and we are going to have to be very careful how we control that.'
