Modelling the recent common ancestry of all living humans

  • Nature volume 431, pages 562566 (30 September 2004)
  • doi:10.1038/nature02842
  • Download Citation
Published online:


If a common ancestor of all living humans is defined as an individual who is a genealogical ancestor of all present-day people, the most recent common ancestor (MRCA) for a randomly mating population would have lived in the very recent past1,2,3. However, the random mating model ignores essential aspects of population substructure, such as the tendency of individuals to choose mates from the same social group, and the relative isolation of geographically separated groups. Here we show that recent common ancestors also emerge from two models incorporating substantial population substructure. One model, designed for simplicity and theoretical insight, yields explicit mathematical results through a probabilistic analysis. A more elaborate second model, designed to capture historical population dynamics in a more realistic way, is analysed computationally through Monte Carlo simulations. These analyses suggest that the genealogies of all living humans overlap in remarkable ways in the recent past. In particular, the MRCA of all present-day humans lived just a few thousand years ago in these models. Moreover, among all individuals living more than just a few thousand years earlier than the MRCA, each present-day human has exactly the same set of genealogical ancestors.

  • Subscribe to Nature for full access:



Additional access options:

Already a subscriber?  Log in  now or  Register  for online access.


  1. 1.

    in Genealogical Demography (eds Dyke, B. & Morrill, W. T.) 85–93 (Academic, New York, 1980)

  2. 2.

    Recent common ancestors of all present-day individuals. Adv. Appl. Probab. 31, 1002–1026, 1027–1038 (1999)

  3. 3.

    , & On the genealogy of a population of biparental individuals. J. Theor. Biol. 203, 303–315 (2000)

  4. 4.

    , , & Mitochondrial genome variation and the origin of modern humans. Nature 408, 708–713 (2000)

  5. 5.

    , , , & Recent common ancestry of human Y chromosomes: Evidence from DNA sequence data. Proc. Natl Acad. Sci. USA 97, 7360–7365 (2000)

  6. 6.

    in Oxford Surveys of Evolutionary Biology (eds Harvey, P. H. & Partridge, L.) 1–44 (Oxford Univ. Press, New York, 1990)

  7. 7.

    American Holocaust: Columbus and the Conquest of the New World (Oxford Univ. Press, New York, 1992)

  8. 8.

    , Death Rates by Age, Race, and Sex, United States, 1900–1953, Vital Statistics—Special Reports Vol. 43 (US Government Printing Office, Washington DC, 1956)

  9. 9.

    Model fitting and hypothesis testing for age-specific mortality data. J. Evol. Biol. 12, 430–439 (1999)

  10. 10.

    The Malthusian parameter of ascents: What prevents the exponential increase of one's ancestors? Proc. Natl Acad. Sci. USA 93, 15276–15278 (1996)

  11. 11.

    , & Distribution of repetitions of ancestors in genealogical trees. Physica A 281, 1–16 (2000)

  12. 12.

    & On the number of ancestors to a DNA sequence. Genetics 147, 1459–1468 (1997)

  13. 13.

    Tasmanian archaeology: Establishing the sequences. Ann. Rev. Anthropol. 24, 423–446 (1995)

  14. 14.

    Fitzhugh, W. W. & Chausonnet, V. (eds) Crossroads of Continents: Cultures of Siberia and Alaska (Smithsonian Institution Press, Washington DC, 1988)

  15. 15.

    et al. Maternal and paternal lineages of the Samaritan isolate: Mutation rates and time to most recent common male ancestor. Ann. Hum. Genet. 67, 153–164 (2003)

  16. 16.

    , , & Pingelap and Mokil atolls: Migration. Am. J. Hum. Genet. 23, 339–349 (1971)

  17. 17.

    Cultures in Contact: World Migrations in the Second Millennium (Duke Univ. Press, Durham, North Carolina, 2002)

  18. 18.

    et al. The genetic legacy of the Mongols. Am. J. Hum. Genet. 72, 717–721 (2003)

  19. 19.

    & Archeology, population genetics and studies of human racial ancestry. Am. J. Phys. Anthropol. 44, 31–50 (1976)

  20. 20.

    & Gene frequencies and microdifferentiation among the Makiritare indians. IV. A comparison of a genetic network with ethnohistory and migration matrices; a new index of genetic isolation. Am. J. Hum. Genet. 22, 538–561 (1970)

  21. 21.

    in Current Developments in Anthropological Genetics (eds Mielke, J. H. & Crawford, M. H.) 135–208 (Plenum, New York, 1980)

  22. 22.

    The coalescent and the genealogical process in geographically structured populations. J. Math. Biol. 29, 59–75 (1990)

  23. 23.

    Genealogy and subpopulation differentiation under various models of population structure. J. Math. Biol. 37, 535–585 (1998)

  24. 24.

    & The study of structured populations—new hope for a difficult and divided science. Nature Rev. Genet. 4, 535–543 (2003)

Download references


The research of D.L.T.R. was supported by the National Institutes of Health.

Author information


  1. Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA

    • Douglas L. T. Rohde
  2. 7609 Sebago Road, Bethesda, Maryland 20817, USA

    • Steve Olson
  3. Department of Statistics, Yale University, New Haven, Connecticut 06520, USA

    • Joseph T. Chang


  1. Search for Douglas L. T. Rohde in:

  2. Search for Steve Olson in:

  3. Search for Joseph T. Chang in:

Competing interests

The authors declare that they have no competing financial interests.

Corresponding author

Correspondence to Douglas L. T. Rohde.

Supplementary information

PDF files

  1. 1.

    Supplementary Methods A

    This file contains additional Methods (Further explanation and derivations of mathematical results) and an extra reference.

  2. 2.

    Supplementary Methods B

    This file contains additional Methods (further details of the computational model), Supplementary Figure 1, Supplementary Table 1 and extra references.


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.