ANDREW BROWN
Journalist, the Guardian; Author, In the Beginning Was the Worm: Finding the Secrets of Life in a Tiny Hermaphrodite

Yes, of course the genetics of human diversity are interesting, and some scientists are interested in them for disinterested motives. But I think it is unfair to Gould to suppose that there are only bad reasons to be leery of this interest, and unfair to Lewontin to suppose that there is anything very much more illuminating or important that we can say than that race is a social construction even if we can find genetic clusters which would, as Armand Leroi suggests, allow a geneticist to look at a sample of my spit and tell from it where all my great great grandparents lived.

In defence of Gould, I would say that of course a little knowledge is a dangerous thing; and the best cure for dangerous knowledge is more and better knowledge. However, there is no guarantee that we will find this further knowledge quickly or at all; while we are looking, great harm may be done with the dangerous and partial stuff. There is nothing unreasonable in wishing that certain discoveries had never been made. Some people would consider lobotomy, or even Freudian psychoanalysis cases in point. I am certain that any research in to human genetic differences will be seized on by racist scientists and racists generally. Whether you think an advance in knowledge is worth this cost is a political judgement with no obvious or final answer.

The Left is often accused of groundless optimism about human nature. In this case Gould was pessimistic and his grounds for pessimism seem reasonable to me. If you look at the way that science is twisted and abused in the current American debates on climate change and creationism, it's difficult to feel that a public debate on the reality of race will be conducted in a spirit of disinterested longing for truth.

But let's look at the sort of knowledge that Leroi wants. The genetics of skin colour are interesting and could perhaps be worked out quite quickly. The genetics of breast shape are possibly even more interesting and I'm sure you could get funding to study them. But the real fascination and the real tabus surround the genetics of intelligence and behaviour. If these turned out to vary between races, as it appears they vary between sexes, we would have a sensational scientific discovery.

Now, one of the points about this list is that the more interesting these qualities are, the harder it is to read them out from the genome. Breast shape may be produced by genes and nutrition, but what constitutes a desirable shape has varied greatly in the last fifty years, and the kind of nutrition that fashionable women allow themselves has varied with this preference too. Similarly, the kinds of intelligence, and the kinds of behaviour, that are rewarded and considered desirable in children, have changed a great deal in the last hundred years, and will presumably change a great deal in the next century too. To call some human trait "socially constructed" doesn't mean we can change it at will; and it certainly doesn't mean there is no genetic component.

This comes out clearly in the classic Wilson/Daly studies of homicide rates. These show there must be a strong genetic component to our species' homicidal behaviour, simply because the pattern stays constant across widely differing societies with widely differing homicide rates. But the evidence which shows us this also shows that changing the environment can hugely diminish the rate at which young men do in fact kill each other. Which half of the story is more important?

Still, we can be certain that the research will be done. Some new things will be found, and on an individual level, they will be important and useful. We will know more about genetic variations among human groups, and we may, just possibly, discover more about the genetics of behaviour and intelligence and how they vary. On that subject we could hardly know less than we do now. The real question is how these two kinds of knowledge will fit together. Will there be any correlation between the clusters of genes that control appearance, which do undoubtedly exist, presumably as a result of sexual selection; and other gene clusters, as yet undiscovered, which affect intelligence and behaviour? It is these second clusters that people are really interested in, and here there is no evidence to suggest that Lewontin's results are misleading and that the variations are greater within races than between them (and that the greatest variation is found in Africa). But we won't know for a very long time because we don't know which genes are involved and even whether they cluster.

In the mean time, all those people who already think they know what "race" means will be convinced that science has proved them right. They will twist the work of decent scientists like Leroi to indecent ends. Gould himself had this happen to him when creationists abused his work on punctuated equilibrium. Only if you think that racism is, in the modern world, less widespread than creationism can you laugh at the spectacle of Gould's ghost wringing his hands.

TIM D. WHITE
Paleontologist; Co-director Middle Awash Human Origins and Evolution Project

Human Variety: Evolution's Creation

Armand Leroi's points are made stronger by adding the dimension of time. Countries and races may seem ancient and fixed without the perspectives of history and evolutionary biology. It is sobering to consider that only fifteen generations separate us from Washington, Jefferson and Napoleon.

Ten thousand generations ago, a man died at the edge of a tropical African lake. The place, now called Herto, is in today's Ethiopia. We now know Herto man by the tools his people fashioned from volcanic rock, and by his skull. His skin was almost certainly dark, but a forensic scientist would be baffled by the shape of the man's skull. It clearly belongs to our species Homo sapiens, but it defies attribution to a specific modern human group.

Whether measured in geological or evolutionary terms, Herto man didn't live very long ago. After all, the well-known Australopithecus female "Lucy" was born nearby, but she had died about 200,000 generations before Herto man was even conceived. By any reckoning, our species is a youngster among hominids, primates, and mammals.

The Herto man lived at the same time that European neanderthals (presumably light-skinned) inhabited a landscape refrigerated by the penultimate glaciation. Therefore, when combined with studies on modern human and neanderthal DNA, it is clear that Pleistocene Earth witnessed hominid biological variation at the species level.

Human evolutionists have long known that today's one-hominid planet is an anomaly rather than the rule. And racial variation would certainly have characterized any of the hominid species spread across major segments of the Old World. We can already dimly perceive a bit of that sub-specific variation in the skeletal fragments already recovered, but we can still only imagine the soft tissue features that would have distinguished Iberian, Malayan and Somalian Homo erectus.

But when did geographic diversity arise within Homo sapiens? By baffling the forensic scientist, the Herto man gives us a clue. His skull is shaped more like a modern Australian aboriginal than a modern Ethiopian, but no modern human matches it exactly.

So the 160,000-year-old Herto cranium shows us that the skeletal features allowing contemporary forensic scientists to differentiate today's Africans from Europeans or Asians had not yet evolved, even at this late date in human evolution. Confirmation comes from studies of the modern human Y-chromosome and mitochondrial DNA. These suggest that the common roots of the human species are very shallow compared to the vast majority of other mammalian species. Whether considered paleontologically or genetically, it appears that much of the physical variation to which Armand Leroi draws our attention evolved during the last little bit of our more-than-six-million-year tenure as a lineage separate from the African chimpanzees.

Like Marco Polo, Herodotus and Columbus, we all recognize that modern human physical variation is geographically patterned. Was this always the case? No, most fundamentally because we were not always modern humans! Phenotypic variation among primates results primarily from Darwinian selection, mate choice, and genetic drift. Our molecules and the fossilized bones of our ancestors indicate that our roots are shallow relative to other mammalian species. Our anatomical and physiological variation inform us about the where and when of our origins.

Our genes, our bodies, and the racial variation in our young species are not social constructs. Rather, these are all the products of evolutionary forces operating over the last couple of hundred millennia. Understanding any of them requires the unique perspective of evolutionary biology.

ALUN ANDERSON
Editor-in-Chief, Publishing Director, New Scientist.

Armand Leroi is bound to please the right wingers with his view that "genetic data show that races clearly do exist". I'm sure that is not his intention but I also doubt that everyone will read as far as his belief that "skin colour does not give the measure of a man, that it tells nothing about his abilities or temperament". That genetics has a bad history of being misunderstood and misapplied scarcely needs restating.

Leroi's call for a better understanding of the genetics of human diversity is welcome. Whether everyone would classify "we don't know why some girls have big breasts and some of them have small breasts" as an "important question", I'm less than sure although it may be one that will attract novel sources of research funding! More generally, knowing more about diversity might settle the question of whether "beauty" is really an expression of biological fitness and that would certainly be worth knowing.

Trying to resurrect race is much less worthwhile. All that has really happened in recent years is that some geneticists have realised that if you measure a number of different genetic differences between people you can then cluster these differences into groups that broadly mirror our common sense notion of race. This is not really too surprising as we would anticipate that if we can make a reasonable guess about someone's origins then must be some set of genetic differences underlying them.

The trouble is that these genetic clusters are not that well defined, still muddle up some people with quite different origins, and have not been associated with anything deep or fundamental about people of different origins. Leroi pretty much says so himself. To fill out the quote above, Leroi says in full that "Some [contributors to the journal Nature Genetics] argued that, looked at the right way, genetic data show that races clearly do exist". Elsewhere we find "Race is merely a shorthand that enables us to speak sensibly, though with no great precision, about genetic rather than cultural or political differences". Leroi at first appears to support the view that classifying people by "race" would at least make it possible to "improve medical care" by tailoring treatment to race. But he quickly goes on to say that: "Everyone agrees that race is a crude way of predicting who gets some disease or responds to some treatment".

Indeed so, for a focus on race can blind doctors to groupings that cut across racial lines. Sickle cell anaemia, for example, is often regarded as an African disease but occurs in a number of groups around the world. Nor would a broad classification based on "racial categories" tell you that Ashkenazi Jews, for example, are prone to a rare mutation that causes breast cancer. These issues have been explored in some depth in New Scientist.

Race is too crude and too shallow a concept to be worth resurrecting even as a scientific shorthand and has already done too much harm. In medicine, it is the individual genotypes determining disease susceptibility and drug reactions that are worth pursuing. If we would like to know more about diversity—why some people have straight and some have curly hair, for example—classifying broad racial clusters does not really help us to find the answer.

Although in my view Leroi overstates the case for race as a useful concept, I still applaud him for speaking about diversity and biology. At a recent session I chaired at the World Economic Forum in Switzerland on Gender and the Brain, the real anger came from US scientists and intellectuals, venting their frustration that any discussion of biological differences relating to sex or race is a forbidden zone in universities in America. Although this session occurred at the height of the controversy over Larry Summers's poorly thought out remarks on female scientists, which certainly raised temperatures, it does indeed seem an indicator, as Leroi put it, that "it's time that we grew up".

May she be granted beauty and yet not
Beauty to make a stranger's eye distraught,
Or hers before a looking-glass, for such,
Being made beautiful overmuch,
Consider beauty a sufficient end,
Lose natural kindness and maybe
The heart-revealing intimacy
That chooses right, and never find a friend.

... Deformity is daring.
It is its essence to o'ertake mankind
By heart and soul, and make itself the equal —
Aye, the superior of the rest. There is
A spur in its halt movements, to become
All that the others cannot, in such things
As still are free to both, to compensate
For stepdame Nature's avarice.

Treason is ne'er successful
Here's the reason:
When it's successful,
Then it's not called "treason."