The Sixth Extinction: Biodiversity and its survival, By Richard Leakey and Roger Lewin, Weidenfeld amp; Nicolson Pounds 18.99

Bernard Wood, who worked with Richard Leakey on crucial projects, reflects on a man of many parts.

The first of these two books chronicles the Leakey family. One of its prominent members, the “alpha male” of the clan, is the driving force of the second. In Ancestral Passions, Virginia Morell traces the phylogeny of the Leakeys and describes the dynamics of that extraordinary scientific family. In doing so she provides us with the details of the ontogeny of the senior author of the second book.

In the The Sixth Extinction, Richard Leakey and Roger Lewin warn us that modern humans are promoting an extinction event that is showing signs of being every bit as awesome as the asteroid impact that put paid to whole suites of plants and animals - the extinction that was, commercially at least, so successfully exploited in the film Jurassic Park.

Aside from the name Leakey, the theme that dominates these two excellent books is power. One book “dissects” a family replete with powerful personalities and reveals something that will come as no surprise to any serious student of human relationships, familial or otherwise. It shows intellectually gifted and charismatic people struggling to come to terms with the challenge of developing functional relationships within their family and in particular with their offspring.

In the process, they discover that the talents that serve them so well in the pursuit and implementation of science sometimes prove to be impediments when applied to parenthood. The other book warns us of the power of modern human behaviour, and in particular of the consequences for biodiversity when the impoverished understandably pursue their search for “free” sources of energy to the detriment of habitats. It is estimated that because of the present rate of destruction and fragmentation of habitats, species will soon begin to disappear at the rate of 100,000 a year.

I have to confess that I am not a neutral commentator as far as Ancestral Passions is concerned. Anyone who reads the index assiduously will find eight entries under Bernard Wood. Who could be neutral when described as “lanky and good natured”? Alas, the description of me as a young scientist working with Leakey now no longer fits a 50-year-old professor struggling to come to terms with the combined effects of the not-so-gradual decline of higher education and of his faculties.

More seriously, my acquaintance with many of the people, and my involvement with not a few of the events, covered in the latter part of the book, allow me to reassure readers that Virginia Morell’s account is well-researched and commendably balanced and fair. Morell’s skill combined with the fact that it is almost impossible to make an account of the life of the Leakeys dull ensures that the reader’s attention is captured as the saga unfolds.

Her research has thrown new light on the events surrounding the decision by the Leakeys and their scientific colleagues to name a new species of Homo. It also reminds us that the decision to extend their work into Ethiopia resulted in the finds that provided the first substantial clue that modern humans evolved in Africa. Finally, it lays to rest many of the wilder accusations that the Leakeys regarded the prehistory of East Africa as their feifdom.

Richard Leakey comes into the book on page 137 and he is the last person to be mentioned by name on the final page. In effect, though, the whole book is relevant to any attempt to try to understand how “nature” and “nurture” have combined to make him the person he is.

By any standards, he had two remarkable parents; Louis was the better known, but arguably Mary had as much, if not more, influence on their sons and it was her input that determined the durability and significance of their scientific achievements. Richard’s was not a conventional childhood for it was spent, both literally and metaphorically, in the wake of a human dynamo and in the shadow of a mother with a formidable capacity for work and an intellect to match.

If Richard was ever to visit a therapist (although my guess is that such an event is about as likely to occur as water is to flow uphill) much would be made of the apparent lack of parental attention. However, it is perhaps just those things that would capture the attention of a therapist that have helped to mould him into the effective and indefatigable character he has become.

Most of us struggle to achieve relatively modest success and a little notoriety in one career, but Richard has made his mark in at least four occupations - palaeoanthropologist, museum director, author and conservationist - and looks to be well on the way to succeeding in a fifth,politics, as well.

His achievements as the leader of a scientific endeavour that had a major and longlasting impact on the history of palaeoanthropology are easily overlooked in the rush to point to the “mistakes” that are alleged to have been made. One of these involves the use of a layer of volcanic ash to provide a date for a skull that has proved to be very important in our understanding of human evolutionary history.

What was at issue was a mismatch between the dates that were being suggested by “biochronology”, that is, using the presence of fossil animals in the strata as a dating method, and the dates for the ash layer that were being produced by what was then the relatively new method of potassium-argon isotope dating. If the “isotope” date was correct, then the skull, which is known by its catalogue number, KNM-ER 1470, would have been more than half a million years older than any comparable specimen, whereas if the “fossil” date was confirmed, then the discovery of the skull would have made much less of an impact.

Initially, it looked as if the fossil clock might be giving misleading results because of biases in the occurrence of some of the fossil animals crucial to its role as a “clock”. Richard and his colleagues, of whom I was one, reasoned that without recourse to the absolute “isotope” dates there is always a risk that the “fossil” clock dates will be consistent but erroneous. As a group we were determined to make sure that the “fossil” method of dating was tested against the new generation of “isotope” dates.

In the event, we were frustrated and ultimately confounded because the “absolute” date we had pinned our hopes on proved to be as fickle as the basis for the “fossil” clock. The supporters of the “fossil” dating method carried the day. However, even with the wonderful clarity that comes with hindsight. I am still convinced that the principle was correct even if the execution was wanting.

In The Sixth Extinction, Leakey and Lewin make a convincing case for the culpability of humankind as the certain agents of what will, unless we modify our behaviour, be an extinction event that will ultimately result in the demise of our own species. We are inextricably enmeshed in the world’s biodiversity and if it is impoverished beyond a certain point we, too, will follow the plants, spiders and fish into the limbo of extinction.

Richard Leakey’s background in palaeoanthropology and conservation, and his two brushes with mortality in the forms of kidney failure and his more recent air crash, probably make him uniquely equipped to bear such an important message.

Even if Richard and his generation do not succeed in alerting mankind to its folly, there are “chips off the old block” in the form of feisty daughters, who probably will. Many may feel that it is appropriate in a book about the Leakeys that the last reference to a human being, on the final page, should be to a vivacious young woman. You will have to read the book to find out who it is - you will not be disappointed.

Bernard Wood is Derby Professor of Anatomy at The University of Liverpool