Creatures attracts a different audience - 40 per cent of the users are female, probably because the software starts to ask some of the most fundamental questions: what is life, what is nurture, how does learning take place, how do you deal with death? It is a mixture of genetics, biochemistry, engineering, artificial life, artistic craft, humour and fun.

Digital DNA is behind the program. “Norns” hatch from eggs on your PC and rely on the user to teach, nurture and play with them. They have a simplified but complete biochemistry and can be crossbred and traded across the Internet. Older Norns actually teach the younger ones without your intervention. Unfortunately, the world also contains “Grendels” who are predatory, cruel and can pass on disease. Monitoring health is very important. Breeding increases diversity and Norns can be distinctive. They even die - death occurs after about 10 hours.

Cyberlife Technology is the creator of the Creatures series of programs. The Creatures Lab is located in Cambridge on the banks of the River Cam. “We have always been surprised by this software, and didn’t know how it was going to go when we brought out Creatures 1,” says Toby Simpson, chief technology officer. “What are you meant to do? Give birth to a creature and bring it up and get it to breed. It is the girls who have achieved some of the most remarkable things with the game.”

The innovative structure of the game has attracted a great deal of interest, far beyond the games world into the academic world of Artificial Life. Most computer games are heavily structured with extravagant amounts of code. The creatures’ behaviour is not scripted, it is emergent from the biological model of the animal itself.

Simpson describes the thinking: “Stephen Grand, who developed the original idea wanted to create something that would have the potential for evolution. We stole our ideas from nature, which is rather good at this stuff. We were taking advantage of a 3.7-billion-year-old research and development program with the advantage that Mother Nature will not sue us for using her intellectual property.”

Stephen modelled a whole load of building blocks and put them all together to mae a complete artificial organism: “The whole program is an extension on the new field of artificial life. Artificial life is about solving complex problems by using large populations of simple small things that you understand. The human being is the ultimate expression of that with 10 trillion cells, each of which is simple and straightforward and each of which in isolation we can understand. Put them all together in the right order and you get a thinking human being.”

Shortly after the launch of Creatures 1 in 1996 one of the users looked at the genome format and worked out where the gene boundaries were. They started taking genes out of the Grendels, who are the bad ones, and splicing them into the Norns who are the good guys. Genetic engineering was taking place!

Eventually Cyberlife supplied a genetics editor and sold thousands of copies. Whole websites went up detailing each gene. “Not simple”, observes Simpson. “You have to set up each and every chemical reaction, sort out the neural dynamics for each part of the brain.”

Simpson, who has developed the new Creatures Adventures, believes that they are into “stealth education”. He claims that is the best kind of education because you don’t know you are receiving it and you are enjoying it. The point was illustrated by a recent conversation with two sisters, aged 11 and 9. The nine-year-old asked why the genetics were aploid and not diploid: “She assured me that with diploid we would get dominant genes. Then she started to talk about the female cycle and oestrogen. She knew that you could check for pregnancy by looking at the combination of gonadotrophin and progesterone. She’d picked that up from Creatures. But you don’t have to pick it up and that is what makes the product interesting. It is an entertainment product meant to be fun not hard work. If you do learn that is a bonus. It is all based on sound scientific principles. We are the only computer company that I know who hires geneticists and biologists as a matter of course to make our organism.”

Stephen Grand’s original vision has subsequently moved away from Cyberlife. To develop his ideas further, he wants to have self-aware life forms living in computers or robots by the year 2020. He saw it as a way of moving from inanimate tools controlled by humans, through to animate tools, then on to tools which are artificially alive. Creatures is just the start.

Creatures 3Cost: pound;34.95www.creatures.co.ukwww.creatures3.com