John Stremlau
a second look
Twenty years after the first nuclear explosion Albert Einstein issued his famous lament about politics falling behind physics. “The unleashed power of the atom,” he warned, “has changed everything save our modes of thinking and we thus drift toward unparalleled catastrophes.”
Africa’s contributions to the nuclear age were poignant but peripheral. Uranium used in the first atomic bombs came from the Congo and South Africa eventually became the first nuclear power to terminate its weapons programme.
Today science is again racing ahead of society. Last year’s successful sequencing of the human genome marks the start of another scientific revolution, one that could yield new technologies for altering human evolution. And for the first time Africans can make a major contributions to the advancement of global scientific knowledge.
This was the theme of Dr Malegapuru William Makgoba’s stirring address last week to a graduating class of science majors at Wits University.
As president of the Medical Research Council (MRC) his main focus was on the frontiers of human genetics. But he also implied that if we fail to deal with the social, political, economic and ethical implications of DNA analysis we too risk “unparalleled catastrophes”.
Advances in biomedical science and social policy must proceed on two levels, altering the beliefs and behaviours of groups and individuals.
At the group level, anyone remotely aware of the advances in genetics over the past decade knows that variants affecting skin colour and facial features are of no scientific significance. They probably involve a few hundred of the billions of nucleotides in any person’s DNA. All groups share common ancestry with the small number of people at times fewer than 20?000 who became isolated in East Africa from their ancestors, those archaic human beings scattered around Europe, Asia and Africa 100?000 to 200?000 years ago.
As our modern ancestors acquired smaller builds and new social and language skills, they migrated across Africa and in all other directions. They peacefully supplanted their archaic counterparts in Europe and then entered the Americas about 12 000 years ago. All this took very little time, in evolutionary terms, which helps explain why humans are far more homogeneous in their essential genetic make-up than most other creatures.
Among man’s most tragic follies has been his persistent and willful restriction of access to social status, economic opportunity, education and political power according to so trivial a criterion as race or some other equally meaningless physical difference. Adaptations to climate, which was in no way linked to intelligence or other abilities, geneticists now agree, are responsible for the slight DNA differences that affect skin colour.
Science at last has confirmed what most theologians and democrats have long believed: all people are created equal. At issue is how to provide equal opportunities and protection for everyone to realise his or her full potential.
Not only do people in all racial and ethnic groups have essentially the same set of genes, we now know all groups also share all the major variants of those genes. This does not really matter in the case of a simple trait such as skin colour but has profound implications for the development of complex attributes such as intelligence or our ability to defend against disease.
Differences in rates of infections among racial groups are not, for the most part, the result of any inherent or genetic differences, but of access to medical care, a basic education and information, an adequate diet, or the degree of mental stress so often a function of economic inequity and social discrimination. Understanding the complexities of individual genetic variations and how to target medical interventions to prevent or treat disease will benefit all groups.
Makgoba’s challenge to the Wits graduates was to see South Africa as one of the world’s most important scientific and social laboratories in the global revolution in human biology. Not surprisingly, he chose as his main example HIV/Aids.
To inform our understanding of how to attack the HI virus at the molecular level and in ways that can be tailored to individual genetic composition, Makgoba noted that South Africa is home to the Khoi and San people, who have the oldest set of genes among mankind today. By studying them, as units at the universities of the Witwatersrand, Western Cape and Cape Town are now doing, South African scientists can take advantage of the genomic and bio-information revolution and make their own major and novel contributions.
This could contribute to the development of vaccines for HIV, tuberculosis (TB), malaria, and more generally help unlock other genetic secrets for developing human capacity.
In unusually frank language for a graduation ceremony, Makgoba issued a familiar but shocking litany of what the Aids crisis will do to our families, friends and nation unless the virus is not contained and defeated. He compared our plight to the plague, or black death, that preceded the European renaissance, reaching Europe in 1347 and England a year later, where it reportedly killed half the people. Such catastrophes are not, he argued, inevitable. Both Thailand and South Africa had an HIV prevalence rate of 0,7% in 1990, while today Thailand is at 2% and South Africa at 22%.
South Africa is now at the leading edge of HIV vaccine development and TB drug innovations. The MRC will invest R75-million more in the next three years to deploy 370 scientists locally and internationally in the search for an HIV vaccine.
South Africa already has nine candidate vaccines, six from our own scientists. Trials will begin shortly. The MRC is also headquarters for a 10-year, R4-billion effort to develop better treatment for TB. For young South African scientists the opportunities to contribute to the well-being of people here and throughout the world is enormous.
Realising the benefits from scientific discoveries for treating HIV/Aids will be meaningless without changes in national policies and personal behaviour. Science, politics and ethics now converge in justifying affirmative action in public health, education and other aspects of capacity building to help historically disadvantaged people better defend themselves against such deadly viruses as HIV/Aids. Equally important, everyone at all levels of society must face and speak the truth about such deeply personal issues of whether, how, and with whom to have sex, for that is the frontline of HIV/Aids prevention.
For the poor and vulnerable, especially girls and women, talk of choice can be cruelly meaningless. It therefore falls to the rest of us to vindicate Makgoba’s belief that South Africa will make major contributions to global understanding of genetic diversity, its relationship to behaviour and health, and halt the spread of deadly diseases that are aggravated by deprivation, most crucially HIV/Aids.
John Stremlau heads the international relations department at the University of the Witwatersrand