Monday, 27 August 2012

Ancestral claims: why has there been comparatively little research into human origins?

It has been said that we live in a golden age of dinosaur discoveries: from Liaoning Province in China to the Dakota Badlands, new species are being named on an almost monthly basis. But if there is a plethora of dinosaur palaeontologists why has there seemingly been so few scientists studying the origin of Homo sapiens? Surely deciphering the ancestry of mankind is one of the great challenges?

The image of hominins has certainly evolved over the past thirty years, even the naming changing in scientific circles (from the broader term hominid), although as the title of the 2003 BBC series' Walking With Cavemen showed, popular perception has been slow to adopt new research. As a child, I had an early 1970s plastic model kit of a Neanderthal Man. I seem to recall it bore more than a passing resemblance to the Morlocks from the 1960 film adaptation of H.G. Wells's The Time Machine, a far cry from the individuals portrayed in Walking With Cavemen and other, more recent, series. Yet this idea of a shambling, zombie-like creature is still to some extent prevalent. Why should this be, when there is now evidence for Neanderthal ritual and art? Are we simply afraid of finding yet more nails in the coffin of human uniqueness (apologies for the rusty metaphor)?

There are still clear elements of taboo to the subject: the humbling  notion of humans being but a 'monkey shaved' was also felt by early evolutionists, with even natural selection co-founder Alfred Russel Wallace believing humanity the product of divine fiat. Perhaps a sense of embarrassment (try watching zoo visitors as they observe apes) combined with Western religious thought has prevented the discipline becoming popular in the way the love of all things dinosaur has skyrocketed since the 1970s.

Then again, it still seems that people misunderstand evolution via natural selection, considering progress as via ladders rather than differentiating bushes. The 2004 discovery of yet another new hominin species, Sahelanthropus tchadensis, led the Christian Science Monitor to describe it as that hoary old misnomer the 'missing link'. This is despite three decades of popularising by the likes of Dawkins, Fortey, Jay Gould, etal, to dispel the notion. You only have to read archaeologist (note: not palaeontologist) Mark Roberts’ account of the seemingly shoestring Homo heidelbergensis excavations at Boxgrove in England to realise that hominin research has been attracting about one per cent of the news (and a zillionth of the funds) directed towards cutting-edge particle physics.

A primary cause for the dearth of public knowledge can be put down to the actual lack of direct fossil evidence. Although Neanderthal remains were the first actually recognised as belonging to a human ancestor, it took several decades after the initial 1829 discovery before the identification was scientifically confirmed. Into the Twentieth Century the lack of finds allowed such embarrassments as the poor-quality Piltdown fake to be taken at face value. It is easy to see at least one key reason why this should be: human ancestry carries so much emotional baggage that it took over forty years before British scientists saw the obvious, instead of following the patriotism and jingoism inspired by the finds.

As it is, the history of hominin palaeontology has been riddled with contention, serendipity, unfortunate accidents and amateur bungling. If anyone wants to disprove the myth of science as a sterile, laboratory-conditioned activity, this sphere provides key evidence par excellence (good to get a rhythm going). From Eugene Dubois hiding his Java Man (Homo erectus) remains for several decades early in the Twentieth Century to the disappearance of Peking Man (also Homo erectus) fossils during the Second World War - not to mention the grinding up of yet more erectus bones for Chinese traditional medicine - the fate of finds is enough to make a dedicated specialist weep.

In addition, the fact that humans and their ancestors primarily evolved in what are today remote African locations with limited infrastructure can only exacerbate the situation. The work can be tedious, physically arduous and rewards few and far between. Yet fossil remains are the backbone of the discipline (almost a pun there, if you really look for it). After all, an increase in the number of finds can also lead to a paradigm shift in understanding: in the last few years it has been possible to undermine the opinion given on the BBC documentary The making of Walking with Dinosaurs, first broadcast back in 2000, that we would never know the colour of any dinosaur, courtesy of feathered Chinese theropod fossils (try saying that three times fast).

However, the last few decades has seen an improvement in the number of finds as funding has been allocated and professional enthusiasm increased. The problem has been that rather than solidifying the story of our ancestral line the number of species has multiplied without aiding the overall picture; there are still plenty of dashed lines on the human family tree. This indeterminacy has meant that a consensus is hard to find. If you examine any two charts of human ancestry, the chances are that they won’t agree. In the face of limited evidence it seems relatively easy for palaeoanthropologists to promote their own theories as to which species are our direct ancestors. Human nature being what it is, the favoured species usually happen to be those discovered by the said promoter. Such behaviour led to a thirty-year rift between two of the key players, Richard Leakey and Donald Johanson, partially over the number of branches on the direct ancestral tree. If anyone thinks the days of feuding scientists as long past (consider for example the Nineteenth Century American dinosaur pioneers Cope and Marsh) this quarrel ought to set the record straight.

One area of research that has undoubtedly given a boost to the understanding of human origins is the ability to retrieve and read ancient DNA. That’s not to say that it has yet produced much in the way of definitive evidence, but it undoubtedly widens the knowledge that can be gained from a paucity of finds. A recent report suggested that Homo sapiens and Neanderthals did not after all interbreed but share a similar genome via common ancestry. This is a reversal of a previous report that in turn countered earlier genetic evidence...and so on.

The relatively recent demise of the Neanderthals has provoked some interesting theories that show how science can reflect the concerns of contemporary society, namely that the violent aspect our species may have been directly responsible. There is currently no firm evidence for deliberate genocide, with other likely culprits ranging from inability to adjust to climate change to a less flexible neural architecture (specifically, missing out on the 'Great Leap Forward' via imaginative cogitation). Recent texts have attempted to downplay innate human aggression but writers closer in time to the world wars and to the heyday of Freudianism, especially Australian anthropologist Raymond Dart and American author Robert Ardrey, had a major influence on the subject with their promotion of the 'killer ape' theory. From 1960 onwards the first serious, sustained research on wild chimpanzees by Jane Goodall inadvertently reinforced the notion of mankind as a predominantly violent species. Given such notions, it is perhaps little wonder that funding has been lacking.

The new century has so far seen something of an improvement, with a large increase in the number of popular books and television programmes reflecting and in turn further developing public interest. The controversy surrounding the nature of the Homo floresiensis finds of 2003 has proved fortuitous, with general news media at long last paying serious attention. The ball may have been started rolling by the Chalcolithic ice mummy Otzi, who was discovered in the Alps in 1991. A young upstart at a mere 5,300 years old, the incredible preservation of the man, his clothing and tools have helped bridge the gap in how we relate to our prehistoric ancestors.

So times they are a-changing. The Ancient Human Occupation of Britain project is a sustained, well-funded effort to examine the past 700,000 years of evidence in the United Kingdom using a plethora of cross-discipline techniques in addition to conventional archaeology and palaeontology. The use of advanced dating methods such as electron spin resonance and the ability to analyse ancient DNA suggest that even without new finds, hominin research in the near future will generate some surprises. All I can say is that it's about time, too!