To put the history of life on planet earth into a time perspective, imagine unrolling a toilet roll down a hillside. If there are 400 sheets of tissue paper in the roll, then the very first life in the oceans is seen at sheet 240. The age of the dinosaurs begins at sheet 19. Dinosaurs in their many forms and great diversity are around for 14 and a half sheets. Dinosaurs are extinct by the end of the Cretaceous, 5 squares from the end, making way for the mammals. Our story and place on the timeline as upright walking apes begins only in the last half of the very last sheet. The human story as Homo sapiens, is represented by less than 2 millimeters of this, some 200,000 years.
Our own individual lifetimes cannot be depicted on this final sheet of the toilet roll as it would be too thin a line, yet we have been witness to more change to the planet, to the diversity of life, global climate and natural habitats in this same time period. We are undoubtedly the cause of the sixth mass extinction event that the planet has seen in its history.
The last 50 years has shown an enormous increase in human population, but also extraordinary leaps in technological innovation. The question that needs to be asked is if we can rise to the opportunity, to use our technology to better understand our impact, to stem the tide of extinction on land and in the oceans, to preserve what we have left, and to discover and understand more about our past. What the fossil record does do is to force us to contemplate our place on the planet. We are but one species of several hominids that inhabited planet earth and like our distant cousins who went extinct fairly recently, our time on planet earth is also finite. It won’t take much to tip the balance against us."