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The evolutionary theory of ageing explains why ageing occurs, giving valuable insight into the mechanisms underlying the complex cellular and molecular changes that contribute to senescence. Such understanding also helps to clarify how the genome shapes the ageing process, thereby aiding the study of the genetic factors that influence longevity and(More)
Ageing is not adaptive since it reduces reproductive potential, and the argument that it evolved to provide offspring with living space is hard to sustain for most species. An alternative theory is based on the recognition that the force of natural selection declines with age, since in most environments individuals die from predation, disease or starvation.(More)
Evolutionary considerations suggest aging is caused not by active gene programming but by evolved limitations in somatic maintenance, resulting in a build-up of damage. Ecological factors such as hazard rates and food availability influence the trade-offs between investing in growth, reproduction, and somatic survival, explaining why species evolved(More)
In so far as it is associated with declining fertility and increasing mortality, senescence is directly detrimental to reproductive success. Natural selection should therefore act in the direction of postponing or eliminating senescence from the life history. The widespread occurrence of senescence is explained by observing that (i) the force of natural(More)
BACKGROUND The growing trend for women to postpone childbearing has resulted in a dramatic increase in the incidence of trisomic pregnancies. Maternal age-related miscarriage and birth defects are predominantly a consequence of chromosome segregation errors during the first meiotic division (MI), which involves the segregation of replicated recombined(More)
Thromboplastins vary in their sensitivity to the haemostatic defect induced by oral anticoagulants. To provide a means of standardising prothrombin time tests, the World Health Organization adopted in 1977 a scheme for calibrating thromboplastins in terms of an International Reference Preparation. Unfortunately, the model on which this scheme was based does(More)
Ageing is a highly complex process; it involves interactions between numerous biochemical and cellular mechanisms that affect many tissues in an organism. Although work on the biology of ageing is now advancing quickly, this inherent complexity means that information remains highly fragmented. We describe how a new web-based modelling initiative is seeking(More)
INTRODUCTION To investigate whether interstitial cells (ICs) are present in the adult mouse bladder, and what transmitters characterize adjacent nerve fibres, as ICs in human and guinea-pig bladder lie close to nerve fibres but transmitters present in these nerves have not yet been reported. MATERIALS AND METHODS Sections of the bladder wall from 12 adult(More)
Evolution theory indicates that ageing is caused by progressive accumulation of defects, since the evolutionary optimal level of maintenance is always below the minimum required for indefinite survival. Evolutionary theories also suggest that multiple processes are operating in parallel, but unfortunately they make no predictions about specific mechanisms.(More)