Montag, 29. August 2011
Science is no stranger to controversy. The pursuit of discovery, of knowledge, is often uncomfortable and disconcerting. I have never been one to shy away from stating what I believe to be the truth, however difficult it might prove to be. This has, at times, got me in hot water.
Rarely more so than right now, where I find myself at the centre of a storm of criticism. I can understand much of this reaction. For if I said what I was quoted as saying, then I can only admit that I am bewildered by it. To those who have drawn the inference from my words that Africa, as a continent, is somehow genetically inferior, I can only apologise unreservedly. That is not what I meant. More importantly from my point of view, there is no scientific basis for such a belief.
I have always fiercely defended the position that we should base our view of the world on the state of our knowledge, on fact, and not on what we would like it to be. This is why genetics is so important. For it will lead us to answers to many of the big and difficult questions that have troubled people for hundreds, if not thousands, of years.
But those answers may not be easy, for, as I know all too well, genetics can be cruel. My own son may be one of its victims. Warm and perceptive at the age of 37, Rufus cannot lead an independent life because of schizophrenia, lacking the ability to engage in day-to-day activities. For all too long, my wife Ruth and I hoped that what Rufus needed was an appropriate challenge on which to focus. But as he passed into adolescence, I feared the origin of his diminished life lay in his genes. It was this realisation that led me to help to bring the human genome project into existence.
In doing so, I knew that many new moral dilemmas would arise as a consequence and would early on establish the ethical, legal and societal components of the genome project. Since 1978, when a pail of water was dumped over my Harvard friend E O Wilson for saying that genes influence human behaviour, the assault against human behavioural genetics by wishful thinking has remained vigorous.
But irrationality must soon recede. It will soon be possible to read individual genetic messages at costs which will not bankrupt our health systems. In so doing, I hope we see whether changes in DNA sequence, not environmental influences, result in behaviour differences. Finally, we should be able to establish the relative importance of nature as opposed to nurture.
One in three people looking for a job in temporary employment bureaux in Los Angeles is a psychopath or a sociopath. Is this a consequence of their environment or their genetic components? DNA sequencing should give us the answer. The thought that some people are innately wicked disturbs me. But science is not here to make us feel good. It is to answer questions in the service of knowledge and greater understanding.
In finding out the extent to which genes influence moral behaviour, we shall also be able to understand how genes influence intellectual capacities. Right now, at my institute in the US we are working on gene-caused failures in brain development that frequently lead to autism and schizophrenia. We may also find that differences in these respective brain development genes also lead to differences in our abilities to carry out different mental tasks.
In some cases, how these genes function may help us to understand variations in IQ, or why some people excel at poetry but are terrible at mathematics. All too often people with high mathematical abilities have autistic traits. The same gene that gives some people such great mathematical abilities may also lead to autistic behaviour. This is why, in studying autism and schizophrenia, we believe that we shall come very close to a better understanding of intelligence and, therefore, of the differences in intelligence.
We do not yet adequately understand the way in which the different environments in the world have selected over time the genes which determine our capacity to do different things. The overwhelming desire of society today is to assume that equal powers of reason are a universal heritage of humanity. It may well be. But simply wanting this to be the case is not enough. This is not science.
To question this is not to give in to racism. This is not a discussion about superiority or inferiority, it is about seeking to understand differences, about why some of us are great musicians and others great engineers. It is very likely that at least some 10 to 15 years will pass before we get an adequate understanding for the relative importance of nature versus nurture in the achievement of important human objectives. Until then, we as scientists, wherever we wish to place ourselves in this great debate, should take care in claiming what are unarguable truths without the support of evidence.
The writer, a Nobel prizewinner for his part in unraveling DNA, is chairman of Cold Spring Harbor Laboratory in the United States
Montag, 22. August 2011
The Evolution of Domain-General Mechanisms in Intelligence and Learning
Dan Chiappe and Kevin MacDonald (2003)
Dan Chiappe and Kevin MacDonald (2003)
For both humans and animals, domain-general mechanisms are fallible but powerful tools for attaining evolutionary goals (e.g., resources) in uncertain, novel environments that were not recurrent features of the environment of evolutionary adaptedness. Domain-general mechanisms interact in complex ways with domain-specific, information encapsulated modules, most importantly by manipulating information obtained from various modules in attempting to solve novel problems. Mechanisms of general intelligence, particularly the executive functions of working memory, underlie analogical reasoning as well as the decontextualization processes that are central to human thought. Although there is a variety of evolved, special purpose learning devices, learning is also characterized by domain-general mechanisms able to achieve evolutionary goals by making novel and serendipitous associations with environmental cues.
Montag, 15. August 2011
Sonntag, 7. August 2011
..."What this means, for example, is that if humans were to disappear save a single race that would repopulate the earth, the diversity loss would be the same as the loss if two couples from a random mating population were to reconstitute a population."
Misunderstandings of Kin Selection and the Delay in Quantifying Ethnic Kinship
Frank Salter (2008)
Frank Salter (2008)
This paper discusses likely causes of a thirty-year delay in quantifying the kinship, or relatedness, between random members of ethnic groups. The introduction consists of reporting that quantification (Harpending 2002; Salter 2002), briefly discussing its constituent theoretical steps, and pointing to its theoretical importance. The main goal is to discuss some of the misconceptions that delayed quantification and which are still widespread in the social and evolutionary literature. Recent population-genetic research has quantified the genetic similarity between random members of an ethnic group as up to three orders of magnitude greater than that computed from genealogies. The kinship between random co-ethnics can exceed that between grandparent and grandchild. Quantifying ethnic kinship, whether within bands, tribes or modern ethnies, is theoretically significant because it is essential for developing and testing evolutionary theories of ethnic altruism, just as understanding the evolution of nepotism began with the quantification of kinship within families. Quantifying ethnic kinship is a prerequisite for exploring the applicability of kin selection theory to ethnicity. The theoretical tools for that quantification were provided by W. D. Hamilton by 1971 yet it was achieved in 2002, a delay of three decades. This paper identifies some of the factors that contributed to this extraordinary delay. These include misinterpretations by leading geneticists and evolutionary theorists that continue to be widely accepted as a basis for rejecting ethnic kinship and related theories. Fallacies and oversights that have impeded the realization of ethnic kinship are described. Refutations are usually available in the mainstream scientific literature from the 1970s and 1980s, though the argument based on the distinction between neutral and functional genes has been empirically falsified only since 2000. Examples are chosen from leading scientists who have made important contributions in other areas of genetics, especially L. L. Cavalli-Sforza, C. Venter, R. Lewontin, and R. Dawkins. An appendix by H. Harpending puts in perspective Lewontin’s argument that ethnies (including races) are genetically insubstantial categories due to variation being greater within than among them, by showing that the same is true of nuclear families. It is now clear that ethnies do generally have genetic identities, that despite blurred boundaries they are in fact, not only in myth, descent groups. The significance of ethnic group similarity can only be apprehended through the lens of theory, not through naïve evaluation of data. If the kinship found within extended families is significant, then probably so too is that found between members of ethnic groups.