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

  • Ageing is the natural effect of time and the environment on living organisms, with death as the end result.

  • Ageing and death are not equivalent, but they are often closely related.

  • Ageing occurs because evolution only selects for reproductive fitness.

  • Ageing represents a combination of genetic factors, epigenetic factors, environmental exposures and chance.

  • The rate of ageing has slowed dramatically in the last 150 years.

  • Better development, including that occurring in utero, may lead to better ageing.

  • Human genetic diseases exist in which one or more aspects of ageing are accelerated.

  • Somatic mutations increase with age, but whether these mutations play a role in ageing is unclear.

  • The maximum lifespan potential for humans is approximately 120 years.

Keywords: lifespan; evolution; genetic aspects; epigenetics; premature ageing

Figure 1.

Patient with Werner syndrome at the age of 55. Photo courtesy of Dr. George Martin;

Figure 2.

Patient with Hutchinson–Gilford (progeria) syndrome at the age of 15. Photo courtesy of Progeria Research Foundation;


Further Reading

Almond D (2006) Is the 1918 influenza pandemic over? Long‐term effects of in utero influenza exposure in the post‐1940 U.S. population. Journal of Political Economics 114: 672–712.

Austad SN (1997) Why We Age. New York: Wiley.

Barker DJP (2007) The origins of the developmental origin theories. Journal of Internal Medicine 261: 412–417.

Finch CE (2007) The Biology of Human Longevity: Inflammation, Nutrition, and Aging in the Evolution of Life Spans. Amsterdam: Elsevier Press.

Finch CE and Kirkwood TBL (2000) Change, Development, and Aging. New York: Oxford University Press.

Fogel RW (2005) Changes in the disparities in chronic diseases during the course of the 20th century. Perspectives in Biology and Medicine 48: S150–S165.

Kirkwood TBL (2008) Understanding ageing from an evolutionary perspective. Journal of Internal Medicine 263: 117–127.

Kolata G (2006–2007) The New Age: (1) So big and healthy grandpa wouldn't even know you; (2) Live long? Die young? Answer isn't just in the genes; (3) Old but not frail: a matter of heart and head; (4) A surprising secret to long life: stay in school.

Kulow BA, Kennedy BK and Monnat RJ (2007) Werner and Hutchison–Gilford progeria syndromes: mechanistic basis of human progeroid diseases. Nature Reviews. Molecular Cell Biology 8: 394–404.

Loeb LA, Wallace DC and Martin GM (2005) The mitochondrial theory of aging and its relationship to reactive oxygen species damage and somatic mtDNA mutations. Proceeding of National Academy of Sciences, USA 102: 18769–18770.

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How to Cite close
Turker, Mitchell(Mar 2009) Ageing. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0001479.pub2]