Ageing
Abstract
We will all grow old and die. The question is why. This question is explored from several perspectives, with the caveat that the answer is not known. Evolutionary pressure does not select for ageing of the individual, but we age nonetheless because evolution only selects for reproductive fitness. Our maximum lifespan potential is fixed at approximately 120 years. This does not mean, however, that how we age is immutable because the rate of human ageing has slowed significantly in the last 150 years, at least in some societies. Thus, the goal of ageing research is to allow us to live longer and healthier lives, with the awareness that we will not live forever.
Key Concepts
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Ageing is the natural effect of time and the environment on living organisms, with death as the end result.
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Ageing and death are not equivalent, but they are often closely related.
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Ageing occurs because evolution only selects for reproductive fitness.
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Ageing represents a combination of genetic factors, epigenetic factors, environmental exposures and chance.
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The rate of ageing has slowed dramatically in the last 150 years.
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Better development, including that occurring in utero, may lead to better ageing.
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Human genetic diseases exist in which one or more aspects of ageing are accelerated.
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Somatic mutations increase with age, but whether these mutations play a role in ageing is unclear.
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The maximum lifespan potential for humans is approximately 120 years.
