Plant behaviour from human imprints and the cultivation of wild cereals in Holocene Sahara

Abstract

The human selection of food plants cannot always have been aimed exclusively at isolating the traits typical of domesticated species today. Each phase of global change must have obliged plants and humans to cope with and develop innovative adaptive strategies. Hundreds of thousands of wild cereal seeds from the Holocene ‘green Sahara’ tell a story of cultural trajectories and environmental instability revealing that a complex suite of weediness traits were preferred by both hunter-gatherers and pastoralists. The archaeobotanical record of the Takarkori rockshelter in southwest Libya covering four millennia of human occupation in the central Sahara gives us a unique insight into long-term plant manipulation and cultivation without domestication. The success of a number of millets was rooted in their invasive-opportunistic behaviour, rewarded during their coexistence with people in Africa. These wild plants were selected for features that were precious in the past but pernicious for agriculture today. Reconnecting past practices with modern farming strategies can help us to seek out the best resources for the future.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Context of the archaeobotanical record of Takarkori rockshelter.
Fig. 2: Multiplot of calibrated (cal bc) radiocarbon dates of the 30 archaeobotanical samples.
Fig. 3: Spot and mix plant accumulations.
Fig. 4: The archaeobotanical record of plant accumulations from the Takarkori rockshelter is unique in showing so clearly the coexistence of gathering and cultivation of wild cereals.
Fig. 5: Morphometry of ellipticity.

References

  1. 1.

    Zeder, M. A. Core questions in domestication research. Proc. Natl Acad. Sci. USA 112, 3191–3198 (2015).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  2. 2.

    García-Granero, J. J., Urem-Kotsou, D., Bogaard, A. & Kotsos, S. Cooking plant foods in the northern Aegean: microbotanical evidence from Neolithic Stavroupoli (Thessaloniki, Greece). Quat. Int. https://doi.org/10.1016/j.quaint.2017.04.007 (2017).

  3. 3.

    Diamond, J. Evolution, consequences and future of plant and animal domestication. Nature 418, 700–707 (2002).

    CAS  Article  PubMed  Google Scholar 

  4. 4.

    Cox, S. in Plant Breeding and Farmer Participation (eds Ceccarelli, E. P. G. S. & Weltzien, E.) 1–26 (FAO, Rome, 2009).

  5. 5.

    Baucom, R. S. & Holt, J. S. Weeds of agricultural importance: bridging the gap between evolutionary ecology and crop and weed science. New Phytol. 184, 741–743 (2009).

    Article  PubMed  Google Scholar 

  6. 6.

    Kuester, A., Conner, J. K., Culley, T. & Baucom, R. S. How weeds emerge: A taxonomic and trait-based examination using United States data. New Phytol. 202, 1055–1068 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  7. 7.

    Smith, B. D. Low-level food production. J. Archaeol. Res. 9, 1–43 (2001).

    Article  Google Scholar 

  8. 8.

    Weiss, E., Kislev, M. & Hartmann, A. Autonomous cultivation before domestication. Science 312, 1608–1610 (2006).

    CAS  Article  PubMed  Google Scholar 

  9. 9.

    Willcox, G., Fornite, S. & Herveux, L. Early Holocene cultivation before domestication in northern Syria. Veg. Hist. Archaeobot. 17, 313–325 (2008).

    Article  Google Scholar 

  10. 10.

    Murphy, D. J. People, Plants & Genes: The Story Of Crops And Humanity. (Oxford Univ. Press, Oxford, 2007).

    Google Scholar 

  11. 11.

    Fuller, D. Q. et al. Convergent evolution and parallelism in plant domestication revealed by an expanding archaeological record. Proc. Natl Acad. Sci. USA 111, 6147–6152 (2014).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  12. 12.

    Meyer, R. S. & Purugganan, M. D. Evolution of crop species: genetics of domestication and diversification. Nat. Genet. 14, 840–852 (2013).

    CAS  Article  Google Scholar 

  13. 13.

    White, C. E. & Makarewicz, C. A. Harvesting practices and early Neolithic barley cultivation at el-Hemmeh, Jordan. Veg. Hist. Archaeobot. 21, 85–94 (2012).

    Article  Google Scholar 

  14. 14.

    Fuller, D. Q. & Allaby, R. G. Seed dispersal and crop domestication: shattering, germination, and seasonality in evolution under cultivation. Annu. Plant Rev. 38, 238–295 (2009).

    Google Scholar 

  15. 15.

    Fuller, D. Q., Allaby, R. G. & Stevens, C. Domestication as innovation: the entanglement of techniques, technology and chance in the domestication of cereal crops. World Archaeol. 42, 13–28 (2010).

    Article  Google Scholar 

  16. 16.

    Purugganan, M. D. & Fuller, D. Q. The nature of selection during domestication. Nature 457, 843–848 (2009).

    CAS  Article  PubMed  Google Scholar 

  17. 17.

    Willcox, G., Nesbitt, M. & Bittmann, F. From collecting to cultivation: transitions to a production economy in the Near East. Veget. Hist. Archaeobot. 21, 81–83 (2012).

    Article  Google Scholar 

  18. 18.

    Kislev, M. E., Weiss, E. & Hartmann, A. Impetus for sowing and the beginning of agriculture: ground collecting of wild cereals. Proc. Natl Acad. Sci. USA 101, 2692–2695 (2004).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  19. 19.

    Biagetti, S. & di Lernia, S. Holocene deposits of Saharan rock shelters: the case of Takarkori and other sites from the Tadrart Acacus Mountains (Southwest Libya). Afr. Archaeol. Rev. 30, 305–338 (2013).

    Article  Google Scholar 

  20. 20.

    Cremaschi, M. et al. Takarkori rock shelter (SW Libya): an archive of Holocene climate and environmental changes in the central Sahara. Quat. Sci. Rev. 101, 36–60 (2014).

    Article  Google Scholar 

  21. 21.

    di Lernia, S. & Tafuri, M. A. Persistent deathplaces and mobile landmarks: The Holocene mortuary and isotopic record from Wadi Takarkori (SW Libya). J. Anthropol. Archaeol. 32, 1–15 (2013).

    Article  Google Scholar 

  22. 22.

    Mercuri, A. M. Plant exploitation and ethnopalynological evidence from the Wadi Teshuinat area (Tadrart Acacus, Libyan Sahara). J. Archaeol. Sci. 35, 1619–1642 (2008).

    Article  Google Scholar 

  23. 23.

    di Lernia, S. Dismantling dung: delayed use of food resources among Early Holocene foragers of the Libyan Sahara. J. Anthropol. Archaeol. 20, 408–441 (2001).

    Article  Google Scholar 

  24. 24.

    di Lernia, S. et al. Colour in context: pigments and other coloured residues from the Early-Middle Holocene site of Takarkori (SW Libya). Archaeol. Anthr. Sci. 8, 381–402 (2016).

    Article  Google Scholar 

  25. 25.

    di Lernia, S., Massamba N'siala, I. & Mercuri, A. M. Saharan prehistoric basketry. Archaeological and archaeobotanical analysis of the early-middle Holocene assemblage from Takarkori (Acacus Mts., SW Libya). J. Archaeol. Sci. 39, 1837–1853 (2012).

    Article  Google Scholar 

  26. 26.

    Dunne, J. et al. First dairying in green Saharan Africa in the fifth millennium BC. Nature 486, 390–394 (2012).

    CAS  Article  PubMed  Google Scholar 

  27. 27.

    Dunne, J., Mercuri, A. M., Evershed, R. P., Bruni, S. & di Lernia, S. Earliest direct evidence of plant processing in prehistoric Saharan pottery. Nat. Plants 3, 16194 (2016).

    Article  PubMed  Google Scholar 

  28. 28.

    Ozenda, P. Flore Et Végétation Du Sahara (Centre National de la Recherche Scientifique, Paris, 2000).

  29. 29.

    Mercuri, A. M. Human influence, plant landscape evolution and climate inferences from the archaeobotanical records of the Wadi Teshuinat area (Libyan Sahara). J. Arid. Environ. 72, 1950–1967 (2008).

    Article  Google Scholar 

  30. 30.

    Song, J., Zhao, Z. & Fuller, D. Q. The archaeobotanical significance of immature millet grains: an experimental case study of Chinese millet crop processing. Veg. Hist. Archaeobot. 22, 141–152 (2013).

    Article  Google Scholar 

  31. 31.

    Moreno-Larrazabal, A., Teira-Brión, A., Sopelana-Salcedo, I., Arranz-Otaegui, A. & Zapata, L. Ethnobotany of millet cultivation in the north of the Iberian Peninsula. Veg. Hist. Archaeobot. 24, 541–554 (2015).

    Article  Google Scholar 

  32. 32.

    Kuijt, I. & Finlayson, B. Evidence for food storage and predomestication granaries 11,000 years ago in the Jordan Valley. Proc. Natl. Acad. Sci. USA 106, 10966–10970 (2009).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  33. 33.

    Cremaschi, M. in Droughts, Food and Culture (ed. Hassan, F. A.) 65–81 (Springer, New York, 2002).

  34. 34.

    Kuper, R. & Kröpelin, S. Climate-controlled Holocene occupation in the Sahara: motor of Africa's evolution. Science 313, 803–807 (2006).

    CAS  Article  PubMed  Google Scholar 

  35. 35.

    Castelletti, L. et al. in The Uan Afuda Cave Hunter-gatherer Societes of Central Sahara (ed. di Lernia, S.) 131–148 (AZA Monographs 1, All’Insegna del Giglio, Firenze, 1999).

  36. 36.

    Cremaschi, M. & Zerboni, A. in Landscape and Societies, Selected Cases (eds Martini, I. P. & Chesworth, W.) 67–89 (Springer, Dordrecht, 2011).

  37. 37.

    Wasylikowa, K., & Dahlberg, J. in The Exploitation of Plant Resources in Ancient Africa (ed. Van der Veen, M.) 11–31 (Springer, New York, 1999).

  38. 38.

    Fuller, D. Q. Contrasting patterns in crop domestication and domestication rates: recent archaeobotanical insights from the Old World. Ann. Bot. 100, 903–924 (2007).

    Article  PubMed  PubMed Central  Google Scholar 

  39. 39.

    De Wet, J. M. J. Cereals for the semi-arid tropics. In Proc. Plant Domestication by Induced Mutation (ed. Ridgman, W. J.) 79–88 (International Atomic Energy Agency, 1986).

  40. 40.

    Walker, S., Wu, H. & Bell, K. Emergence and seed persistence of Echinochloa colona, Urochloa panicoides and Hibiscus trionum in the sub-tropical environment of north-eastern Australia. Plant Prot. Q 25, 127 (2010).

    Google Scholar 

  41. 41.

    Clarke, J. et al. Climatic changes and social transformations in the Near East and North Africa during the ‘long’ 4th millennium BC: a comparative study of environmental and archaeological evidence. Quat. Sci. Rev. 136, 96–121 (2016).

    Article  Google Scholar 

  42. 42.

    Khedr, A., Serag, M., Shaaban, H. & Abogadallah, G. Differential responses of aquatic and aerobic forms of Echinochloa crus-galli (L.) Beauv. and E. colona (L.) Link. by morpho-physiological and molecular analysis. Environ. Earth Ecol. 1, 81–93 (2017).

    Article  Google Scholar 

  43. 43.

    Andrew, S. M., Totland, Ø. & Moe, S. R. Invasion of the cosmopolitan species Echinochloa colona into herbaceous vegetation of a tropical wetland system. Ecol. Res. 29, 969 (2014).

    Article  Google Scholar 

  44. 44.

    Zedler, J. B. & Kercher, S. Causes and consequences of invasive plants in wetlands: opportunities, opportunists, and outcomes. Crit. Rev. Plant Sci. 23, 431–452 (2004).

    Article  Google Scholar 

  45. 45.

    Smith, B. D. General patterns of niche construction and the management of ‘wild’ plant and animal resources by small-scale pre-industrial societies. Phil. Trans. R. Soc. B 366, 836–848 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  46. 46.

    Abbo, S., Gopher, A., Rubin, B. & Lev-Yadun, S. On the origin of Near Eastern founder crops and the ‘dump-heap hypothesis’. Genet. Resour. Crop. Ev. 52, 491–495 (2005).

    Article  Google Scholar 

  47. 47.

    Fuller, D. Q. & Hildebrand, E. Domesticating Plants in Africa (eds Mitchell, P. & Lane, P.) 507–525 (Oxford Univ. Press, Oxford, 2013).

  48. 48.

    D'Andrea, A. C., Klee, M. & Casey, J. Archaeobotanical evidence for pearl millet (Pennisetum glaucum) in sub-Saharan West Africa. Antiquity 75, 341–348 (2001).

    Article  Google Scholar 

  49. 49.

    Wu, W. et al. A single-nucleotide polymorphism causes smaller grain size and loss of seed shattering during African rice domestication. Nat. Plants 3, 17064 (2017).

    CAS  Article  PubMed  Google Scholar 

  50. 50.

    González, A. T. & Morton, C. M. Molecular and morphological phylogenetic analysis of Brachiaria and Urochloa (Poaceae). Mol. Phylogenet. Evol. 37, 36–44 (2005).

    Article  Google Scholar 

  51. 51.

    Yang, X. et al. Barnyard grasses were processed with rice around 10000 years ago. Sci. Rep. 5, 16251 (2015).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  52. 52.

    Milla, R., Osborne, C. P., Turcotte, M. M. & Violle, C. Plant domestication through an ecological lens. Trends Ecol. Evol. 30, 463–469 (2015).

    Article  PubMed  Google Scholar 

  53. 53.

    Vigueira, C. C., Olsen, K. M. & Caicedo, A. L. The red queen in the corn: agricultural weeds as models of rapid adaptive evolution. Heredity 110, 303–311 (2013).

    CAS  Article  PubMed  Google Scholar 

  54. 54.

    Gurevitch, J., Scheiner, S. M. & Fox, G. A. The Ecology of Plants 258–259 (Sinauer, Sunderland, MA, 2002).

  55. 55.

    Kohli, R. K., Batish, D. R., & Singh, H. P. in Handbook of Sustainable Weed Management (eds Singh, H. P. et al.) 1–19 (Haworth, New York, 2006).

  56. 56.

    Agrawal, A. A. Phenotypic plasticity in the interactions and evolution of species. Science 294, 321–326 (2001).

    CAS  Article  PubMed  Google Scholar 

  57. 57.

    Aldrich, R. J. Weed-Crop Ecology: Principles in Weed Management (New Breton, North Scituate, MA, 1984).

    Google Scholar 

  58. 58.

    Cremaschi, M. & di Lernia, S. Holocene climatic changes and cultural dynamics in the Libyan Sahara. Afr. Archaeol. Rev. 16, 211–238 (1999).

    Article  Google Scholar 

  59. 59.

    Bronk Ramsey, C. Bayesian analysis of radiocarbon dates. Radiocarbon 51, 337–360 (2009).

    Article  Google Scholar 

  60. 60.

    Wasylikowa, K. Holocene flora of the Tadrart Acacus area, SW Libya, based on plant macrofossils from Uan Muhuggiag and Ti-n-Torha/Two Caves archaeological sites. Origini 16, 125–159 (1992).

    Google Scholar 

  61. 61.

    Wasylikowa, K. Exploitation of wild plants by prehistoric peoples in the Sahara. Würzburger Geogr. Arbeit. 84, 247–262 (1992).

    Google Scholar 

  62. 62.

    Mercuri, A. M. in UanTabu in the Settlement History of the Libyan Sahara, Arid Zone Archaeology, Monographs 2 (ed. Garcea, E. A. A.) 161–188 (All’Insegna del Giglio, Firenze, 2001).

  63. 63.

    Olmi, L. et al. Cereali selvatici nel Tadrart Acacus—Sahara Centrale, durante l'Olocene iniziale e l’Olocene medio. Atti Soc. Nat. Mat. Modena 137, 411–430 (2007).

    Google Scholar 

  64. 64.

    Clayton, W. D. & Renvoize, S. A. Flora of Tropical East Africa: Gramineae (Part 3) (ed. Polhill, R. M.) 451–898 (East African Governments, Balkema, Rotterdam, 1982).

  65. 65.

    Sheriff, A. S. & Siddiqi, M. A. in Flora of Libya (ed. El-Gadi, A. A.) (Al Faateh Univ., Tripoli, 1988).

  66. 66.

    Boulos, L. Flora of Egypt: Volume four: Monocotyledons (Alismataceae–Orchidaceae) (Al Hadara, Cairo, 2005).

  67. 67.

    Lansdown, R. V. Echinochloa colona (IUCN, 2013); https://doi.org/10.2305/IUCN.UK.2013-1.RLTS.T164380A1047208.en

  68. 68.

    Hilu, K. W. Evidence for RAPD markers in the evolution of Echinochloa millets (Poaceae). Plant Syst. Evol. 189, 247–257 (1994).

    CAS  Article  Google Scholar 

  69. 69.

    Sood, S. et al. Barnyard millet—a potential food and feed crop of future. Plant Breed. 134, 135–147 (2015).

    Article  Google Scholar 

  70. 70.

    Yamaguchi, H., Utano, A. Y. A., Yasuda, K., Yano, A. & Soejima, A. A molecular phylogeny of wild and cultivated Echinochloa in East Asia inferred from non-coding region sequences of trnT-L-F. Weed Biol. Manag. 5, 210–218 (2005).

    CAS  Article  Google Scholar 

  71. 71.

    Carman, J. G., Jamison, M., Elliott, E., Dwivedi, K. K. & Naumova, T. N. Apospory appears to accelerate onset of meiosis and sexual embryo sac formation in sorghum ovules. Plant Biol. 11, 9 (2011).

    Google Scholar 

  72. 72.

    Olmi, L. et al. in Windows on the African Past: Contemporary Approaches to African Archaeobotany 175–184 (Africa Magna, Frankfurt, 2012).

  73. 73.

    Fornaciari, R., Fornaciari, S., Francia, E., Mercuri, A. M. & Arru, L. Panicum spikelets from the Early Holocene Takarkori rockshelter (SW Libya): archaeo-molecular and -botanical investigations. Plant Biosyst. 152, 1–13 (2018).

    Article  Google Scholar 

  74. 74.

    Martinoli, D. & Nesbitt, M. Plant stores at pottery Neolithic Höyücek, Southwest Turkey. Anatol. Stud. 53, 17–32 (2003).

    Article  Google Scholar 

Download references

Acknowledgements

This research is part of the activity of The Archaeological Mission in the Sahara, Sapienza University of Rome. Funds have been granted by Sapienza University of Rome (Grandi Scavi di Ateneo) and by the Italian Minister of Foreign Affairs (DGSP) entrusted to S.d.L. Libyan colleagues of the Department of Archaeology in Tripoli and Ghat are thanked. Funds for morphometrical and genetic analyses were provided by the project ‘SELCE—SELvaticiCEreali: il futuro nella risposta delle piante ai cambiamenti climatici’, sect. Scientific and Technological Research (Sime n.2015.0033), funded by the FCRMO-Fondazione Cassa di Risparmio di Modena, directed by A.M.M. We thank E. Milburn and J. Dunne who helped to clarify some expressions in English.

Author information

Affiliations

Authors

Contributions

S.d.L. and A.M.M. conceived and planned the project. A.M.M. and S.d.L. wrote the paper. A.M.M. studied the archaeobotanical record and S.d.L. the stratigraphic and archaeological context. R.F. performed morphometry and data analysis. M.G. performed the GIS analysis. S.V. did the entomological study. S.d.L. designed and directed the excavations and field sampling. All authors read and approved the final manuscript.

Corresponding authors

Correspondence to Anna Maria Mercuri or Savino di Lernia.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Table 1, Supplementary Figures 1 and 2, Supplementary Data, Supplementary References.

Life Sciences Reporting Summary

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Mercuri, A.M., Fornaciari, R., Gallinaro, M. et al. Plant behaviour from human imprints and the cultivation of wild cereals in Holocene Sahara. Nature Plants 4, 71–81 (2018). https://doi.org/10.1038/s41477-017-0098-1

Download citation

Further reading

Search

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