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EMBL/EMBO Joint Conference 2004

Tom Kirkwood, University of Newcastle, UK

Biography

Tom Kirkwood was born on 6 July 1951 in Durban, South Africa. Educated in biology and mathematics at the Universities of Cambridge and Oxford, he worked at the UK National Institute for Medical Research from 1981 until 1993, when he became Britainës first Professor of Biological Gerontology at the University of Manchester. In 1999, he was appointed Professor of Medicine at the University of Newcastle-upon-Tyne, where he is Co-Director of the Institute for Aging and Health and heads the Department of Gerontology. He has been Chair of the British Society for Research on Aging, Governor and Chair of the Research Advisory Council of the medical research charity 'Research into Aging', and Chair of the UK Foresight Task Force on 'Health Care of Older People'. He is author of the award-winning books Time of Our Lives: the Science of Human Aging and of Chance, Development and Aging, co-authored with leading US gerontologist Caleb Finch. He gave the BBC Reith Lectures in 2001 on The End of Age (also published in book form) and has contributed to numerous television and radio documentaries and discussions about aging. Kirkwood has been actively involved in aging research since 1975. His work on the disposable soma theory, first proposed in 1977, provides an evolutionary explanation of aging that makes testable predictions about cell and molecular mechanisms and the genetic basis of longevity. The current focus of his research group is on testing these ideas, particularly the role of cell stress response and maintenance systems in aging and longevity. The group has a core interest in modelling the complex molecular mechanisms that contribute to aging and has pioneered network models that permit analysis of interactions between different contributing processes. At an experimental level, the group focuses on integrative mechanisms of cell aging and recently identified some of the first clear evidence for intrinsic age-related changes in the functional properties of tissue stem cells. At a population level, the group has shown evidence in human records of a trade-off between fertility and longevity, as predicted by the disposable soma theory, and has developed evolutionary models to explain menopause in humans and the life-extending effects of calorie restriction in rodents.

Abstract

Times of our lives: What controls length of life?

The last decades have seen exciting progress in solving one of the greatest puzzles in the life sciences: why do we age and what controls length of life? Evidence points to a modest but significant genetic contribution to human lifespan, explaining about 25 per cent of the variation in longevity within the population. However, the genetic contribution to aging comes about indirectly, not through genes that actively bring about senescence and death but through genes that regulate survival. Our survival mechanisms are outstanding but evolved at a time when extrinsic mortality was much more severe and when reproduction was a much higher priority than being able to live forever. Some of the most important genetic factors are indeed proving to be those that involve trade-offs, for example, balancing the benefits of increased fertility against increased survival. There are also important interactions between genetic predisposition for a longer or shorter life and environmental or chance factors, which in turn may be influenced by lifestyle or socio-economic circumstances. There is much greater plasticity in the aging process than has hitherto been recognised, and it is this plasticity that underlies, for example, the actions of long-term calorie restriction in extending life span. The urgency of aging research has never been higher and it is therefore fortunate that we can at last anticipate rapid progress in further unravelling not only the genes that influence longevity but also the detailed molecular mechanisms which are at play. The complexity of aging is such that the scale of the task should not be underestimated. In an age of science when increasingly we are beginning to appreciate the importance of the integrative approach ‰ assembling a composite picture from the many important discoveries that have flowed from highly focused, reductionist techniques ‰ aging can be seen as one where the discipline of 'systems biology' has a great deal to contribute. Expectations of life have never been greater; it is essential that science engages directly and realistically with delivering the knowledge base that can support a greater quality of life in old age.