Louis Leakey sent me to Gombe with the hope that a better understanding of chimpanzee behaviour might provide us with a window on our past.

Our study of Chimpanzees had helped to pinpoint not only the similarities between them and us, but also those ways in which we are most different. Admittedly, we're not the only beings with personalities, reasoning powers, altruism and emotions, nor are we the only beings capable of mental as well as physical suffering. But our intellect has grown mightedly in complexity since the first true man branched off from the ape man stock some 2 million years ago and we, and we, and only we, had developed a sophisticated spoken language.

For the first time in evolution, a species evolved was able to teach its young about objects and events not present, to pass on wisdom ? from the successes and mistakes of the past. With language, we can ask as can no other living being, those questions about who we are and why we're here. And this highly developed intellect means surely that we have a responsibility towards the other life forms of our planet, whose continued existence is threatened by the thoughtless behaviour of our own human species.

When I look back over my life, seems I've been extraordinarily lucky. Although as my mother Van always says, luck was only part of the story. She's always believed that success comes through determination and hard work, and that fault is not in our stars, but in ourselves that we're under? I certainly believe that's true. Yet I have worked hard all my life that I have to admit that the starts seem to have played their part, too.