Immortality of the Germ-Line versus Disposability of the Soma

  • Thomas B. L. Kirkwood


The germ-line of species is immortal, at least in the sense that an unbroken continuity extends backwards in time to the origin of terrestrial life and forwards in time to an indeterminate future. This observation is a truism. However, when set against the fact that the bodies of higher animals are intrinsically mortal, yet composed of the same basic materials as their germ cells, the observation leads to the central puzzle of gerontology. Each new-born individual begins its life as young as did each of its ancestors but with the same certitude, if it does not meet with an earlier accident, that within a specific span of time it will arrive, through a process of steadily accelerating decrepitude, at death. The puzzle has two sides: why and how has the somatic part of higher animals come to be mortal, and how is the germ-line kept free of the progressive deterioration in the soma?


Germ Cell Somatic Cell Natural Increase Germ Cell Lineage Random Defect 
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  1. Bernstein, H., 1977, Germ line recombination may be primarily a manifestation of DNA repair processes, J. Theor. Biol., 69:371PubMedCrossRefGoogle Scholar
  2. Charlesworth, B., 1980, “Evolution in Age-Structured Populations,” Cambridge University Press, Cambridge.Google Scholar
  3. Comfort, A., 1979, “The Biology of Senescence,” 3rd edition, Churchill Livingstone, Edinburgh.Google Scholar
  4. Francis, A. A., Lee, W. H., and Regan, J. D., 1981, The relationship of DNA excision repair of ultraviolet-induced lesions to the maximum lifespan of mammals, Mech. Ageing Dev., 16:181.PubMedCrossRefGoogle Scholar
  5. Haldane, J. B. S., 1941, “New Paths in Genetics,” Allen and Unwin, London.Google Scholar
  6. Hall, K. Y., Hart, R. W., Benirschke, A. K., and Walford, R. L., 1984, Correlation between ultraviolet-induced DNA repair in primate lymphocytes and species maximum achievable lifespan, Mech. Ageing Dev., 24:163.PubMedCrossRefGoogle Scholar
  7. Hart, R. W., and Setlow, R. B., 1974, Correlation between deoxyribonucleic acid excision repair and lifespan in a number of mammalian species, Proc. Nat. Acad. Sci., U.S.A., 71:2169.CrossRefGoogle Scholar
  8. Kirkwood, T. B. L., 1977, Evolution of ageing, Nature, 270:301.PubMedCrossRefGoogle Scholar
  9. Kirkwood, T. B. L., 1981, Repair and its evolution: survival versus reproduction, in: “Physiological Ecology: An Evolutionary Approach to Resource Use,” C. R. Townsend and P. Calow, eds., Blackwell Scientific Publications, Oxford.Google Scholar
  10. Kirkwood, T. B. L., 1985, Comparative and evolutionary aspects of longevity, in: “Handbook of the Biology of Aging,” C. E. Finch and E. L. Schneider, eds., Van Nostrand Reinhold, New York.Google Scholar
  11. Kirkwood, T. B. L., and Cremer, T., 1982, Cytogerontology since 1881: a reappraisal of August Weismann and a review of modern progress, Hum. Genet., 60:101.PubMedCrossRefGoogle Scholar
  12. Kirkwood, T. B. L., and Holliday, R., 1979, The evolution of ageing and longevity, Proc. Roy. Soc., Lond., B205:531.CrossRefGoogle Scholar
  13. Kirkwood, T. B. L., and Holliday, R., 1986, Ageing as a consequence of natural selection, in: “The Biology of Human Ageing,” K. J. Collins and A. H. Bittles, eds., Cambridge University Press, Cambridge.Google Scholar
  14. Medawar, P. B., 1952, “An Unsolved Problem in Biology,” H. K. Lewis, London.Google Scholar
  15. Medvedev, Z. A., 1981, On the immortality of the germ line: genetic and biochemical mechanisms. A review, Mech. Ageing Dev., 17:331.PubMedCrossRefGoogle Scholar
  16. Reichman, O. J., 1984, Evolution of regeneration capabilities, Am. Nat., 123:752.CrossRefGoogle Scholar
  17. Sacher, G. A., 1978, Evolution of longevity and survival characteristics in mammals, in: “The Genetics of Aging,” E. L. Schneider, ed., Plenum, New York.Google Scholar
  18. Sheldrake, A. R., 1974, The ageing, growth and death of cells, Nature, 250:381.CrossRefGoogle Scholar
  19. Topp, W., Hall, J. D., Rifkin, D., Levine, A. J., and Pollack, R., 1977, The characterisation of SV40-transformed cell lines derived from mouse teratocarcinoma: growth properties and differentiated characteristics, J. Cell. Physiol., 93–269.Google Scholar
  20. Townsend, C. R., and Calow, P. C., 1981, “Physiological Ecology: An Evolutionary Approach to Resource Use,” Blackwell Scientific Publications, Oxford.Google Scholar
  21. Treton, J. A., and Courtois, Y., 1982, Correlation between DNA excision repair and mammalian lifespan in lens epithelial cells, Cell Biol. Int. Rep., 6:253.PubMedCrossRefGoogle Scholar
  22. Weismann, A., 1890, Untitled correspondence, Nature, 41:317 (reprinted as Appendix 2 in Kirkwood, T. B. L., and Cremer, T., 1982, cited above).CrossRefGoogle Scholar
  23. Williams, G. C., 1957, Pleiotropy, natural selection and the evolution of senescence, Evolution, 11:398.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • Thomas B. L. Kirkwood
    • 1
  1. 1.National Institute for Medical ResearchLondonEngland

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