Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Questioning the evidence for Earth's oldest fossils


Structures resembling remarkably preserved bacterial and cyanobacterial microfossils from 3,465-million-year-old Apex cherts of the Warrawoona Group in Western Australia1,2,3,4 currently provide the oldest morphological evidence for life on Earth and have been taken to support an early beginning for oxygen-producing photosynthesis5. Eleven species of filamentous prokaryote, distinguished by shape and geometry, have been put forward as meeting the criteria required of authentic Archaean microfossils1,2,3,4,5, and contrast with other microfossils dismissed as either unreliable or unreproducible1,3,6,7. These structures are nearly a billion years older than putative cyanobacterial biomarkers8, genomic arguments for cyanobacteria9, an oxygenic atmosphere10 and any comparably diverse suite of microfossils5. Here we report new research on the type and re-collected material, involving mapping, optical and electron microscopy, digital image analysis, micro-Raman spectroscopy and other geochemical techniques. We reinterpret the purported microfossil-like structure as secondary artefacts formed from amorphous graphite within multiple generations of metalliferous hydrothermal vein chert and volcanic glass. Although there is no support for primary biological morphology, a Fischer–Tropsch-type synthesis of carbon compounds and carbon isotopic fractionation is inferred for one of the oldest known hydrothermal systems on Earth.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Geological sketch map of the Apex chert at Chinaman Creek, showing sample numbers and site of the Schopf ‘microfossil’ locality (sample 4) from a metalliferous hydrothermal chert breccia vein that cross-cuts hydrothermally altered pillow basalt.
Figure 2: Automontages of inferred artefacts from the Apex chert.
Figure 3: Automontages of inferred artefacts from the Apex chert.
Figure 4: Raman spectra of associated graphitic objects (<1 mm apart) within NHM V.63165.

Similar content being viewed by others


  1. Schopf, J. W. & Packer, B. M. Early Archean (3.3 billion to 3.5 billion-year-old) microfossils from Warrawoona Group, Australia. Science 237, 70–73 (1987).

    Article  ADS  CAS  Google Scholar 

  2. Schopf, J. W. in The Proterozoic Biosphere: a Multidisciplinary Study (eds Schopf, J. W. & Klein, C.) 25–39 (Cambridge University Press, Cambridge, 1992).

    Book  Google Scholar 

  3. Schopf, J. W. Microfossils of the Early Archean Apex Chert: new evidence of the antiquity of life. Science 260, 640–646 (1993).

    Article  ADS  CAS  Google Scholar 

  4. Schopf, J. W. in Early Life on Earth (ed. Bengtson, S.) 193–206 (Columbia University Press, New York, 1994).

    Google Scholar 

  5. Schopf, J. W. The Cradle of Life (Princeton Univ. Press, New York, 1999).

    Google Scholar 

  6. Buick, R., Dunlop, J. S. R. & Groves, D. I. Stromatolite recognition in ancient rocks: an appraisal of irregularly laminated structures in an early Archaean chert-barite unit from North Pole, Western Australia. Alcheringa 5, 161–181 (1981).

    Article  Google Scholar 

  7. Buick, R. Microfossil recognition in Archean rocks: an appraisal of spheroids and filaments from a 3500 M.Y. old chert-barite unit at North Pole, Western Australia. Palaios 5, 441–459 (1990).

    Article  ADS  Google Scholar 

  8. Summons, R. E., Jahnke, L. L., Hope, M. & Logan, G. A. 2-Methylhopanoids as biomarkers for cyanobacterial oxygenic photosynthesis. Nature 400, 554–557 (1999).

    Article  ADS  CAS  Google Scholar 

  9. Hedges, S. B. et al. A genomic timescale for the origin of eukaryotes. BioMed Central Evol. Biol. 1, article 4, 1–10 (2001).

    Google Scholar 

  10. Catling, D., Zahnle, K. J. & McKay, C. P. 2001. Biogenic methane, hydrogen escape, and the irreversible oxidation of early Earth. Science 293, 839–843 (2001).

    Article  ADS  CAS  Google Scholar 

  11. Van Kranendonk, M. J. Volcanic degassing, hydrothermal circulation and the flourishing of life on Earth: new evidence from the c. 3.45 Ga Warrawoona Group, Pilbara Craton, Western Australia. Precambrian Res. (in press).

  12. Nijman, W., De Bruin, K. & Valkering, M. Growth fault control of early Archaean cherts, barite mounds, and chert-barite veins, North Pole Dome, Eastern Pilbara, Western Australia. Precambr. Res. 88, 25–52 (1998).

    Article  ADS  CAS  Google Scholar 

  13. Strauss, H. & Moore, T. B. in The Proterozoic Biosphere: a Multidisciplinary Study (eds Schopf, J. W. & Klein, C.) 711–798 (Cambridge University Press, Cambridge, 1992).

    Google Scholar 

  14. de Ronde, C. E. J. & Ebbesen, T. W. 3.2 b.y. of organic compound formation near sea-floor hot springs. Geology 24, 791–794 (1996).

    Article  ADS  CAS  Google Scholar 

  15. Robert, F. Carbon and oxygen isotope variations in Precambrian cherts. Geochim. Cosmochim. Acta 52, 1473–1478 (1988).

    Article  ADS  CAS  Google Scholar 

  16. Shen, Y., Buick, R. & Canfield, D. E. Isotopic evidence for microbial sulphate reduction in the early Archaean era. Nature 410, 77–81 (2001).

    Article  ADS  CAS  Google Scholar 

  17. Awramik, S. M. & Semikhatov, M. A. The relationship between morphology, microstructure, and microbiota in three vertically intergrading stromatolites from the Gunflint Iron Formation. Can. J. Earth Sci. 16, 484–495 (1979).

    Article  ADS  Google Scholar 

  18. Mendelson, C. V. & Schopf, J. W. in The Proterozoic Biosphere: a Multidisciplinary Study (eds Schopf, J. W. & Klein, C.) 867–951 (Cambridge University Press, Cambridge, 1992).

    Google Scholar 

  19. Kudryatsev, A. B., Schopf, J. W., Agresti, D. G. & Wdowiak, T. J. In situ laser-raman imagery of Precambrian microscopic fossils. Proc. N. Am. Acad. Sci. 98, 823–826 (2001).

    Article  ADS  Google Scholar 

  20. Wopenka, B. & Pasteris, J. D. Structural characterization of kerogens to granulite-facies graphite: applicability of Raman microprobe spectroscopy. Am. Mineralogist 78, 533–557 (1993).

    CAS  Google Scholar 

  21. Tuinstra, F. & Koenig, J. L. Raman spectrum of graphite. J. Chem. Phys. 53, 1126–1130 (1970).

    Article  ADS  CAS  Google Scholar 

  22. Oehler, J. H. Hydrothermal crystallization of silica gel. Bull. Geol. Soc. Am. 87, 1143–1152 (1976).

    Article  CAS  Google Scholar 

  23. Baker, R. T. K & Harris, P. in Chemistry and Physics of Carbon (ed. Walker, P. L. & Thrower, P. A.) 2–165 (Dekker, New York, 1978).

    Google Scholar 

  24. Grotzinger, J. P. & Rothman, D. H. An abiotic model for stromatolite morphogenesis. Nature 383, 423–425 (1996).

    Article  ADS  CAS  Google Scholar 

  25. Westall, F. et al. Early Archaean fossil bacteria and biofilms in hydrothermally-influenced sediments from the Barberton greenstone belt, South Africa. Precambr. Res. 106, 93–116 (2001).

    Article  ADS  CAS  Google Scholar 

  26. Holm, N. G. & Charlou, J. L. Initial idicators of abiotic formation of hydrocarbons in the Rainbow ultramafic hydrothermal system, Mid-Atlantic Ridge. Earth Planet. Sci. Lett. 191, 1–8 (2001).

    Article  ADS  CAS  Google Scholar 

  27. Lancet, M. S. & Anders, E. Carbon isotope fractionation in Fischer–Tropsch synthesis and in meteorites. Science 170, 980–982 (1970).

    Article  ADS  CAS  Google Scholar 

  28. Kagi, H. et al. Proper understanding of down-shifted Raman spectra of natural graphite: direct estimation of laser-induced rise in sample temperature. Geochim. Cosmochim. Acta 58, 3527–3530 (1994).

    Article  ADS  CAS  Google Scholar 

  29. Matthews, D. E. & Hayes, J. M. Isotope-ratio-monitoring gas chromatography – mass spectrometry. Anal. Chem. 50, 1465–1473 (1978).

    Article  CAS  Google Scholar 

  30. Clayton, R. N. & Mayeda, T. K. The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis. Geochim. Cosmochim. Acta 27, 43–52 (1963).

    Article  ADS  CAS  Google Scholar 

Download references


We thank C. A. Stoakes, A. T. Brasier and D. Huston for assistance with field work; N. Charnley, D. Sansom and A. T. Brasier for laboratory support; the Natural History Museum, London, for the loan of the type slides and re-collected material; R. Buick, J. Farmer, J. P. Grotzinger, A. H. Knoll, E. Nisbet, S. Moorbath, J. W. Schopf and R. E. Summons for comments on earlier versions of the manuscript; and The Royal Society, NASA Astrobiology Institute and The Carnegie Institution of Washington for support. This paper is published by permission of the Director of the Geological Survey of Western Australia.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Martin D. Brasier.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Brasier, M., Green, O., Jephcoat, A. et al. Questioning the evidence for Earth's oldest fossils. Nature 416, 76–81 (2002).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing