The Evolutionary Origins of Agriculture

Key points:

  • Investigates the relationship between human and environmental selective pressures and plant ecological characteristics through experimental ecology.
  • Identifies early genetic trait selection in crop plants through simulation of phylogenetic relationships and DNA analysis of barley landraces.
  • Generates measurements of archaeological plant remains from pre- and early Neolithic sites in Western Asia, and attempts to identify the spatial and temporal location of selection for particular phenotypes through statistical analyses and GIS mapping.

This project aims to improve understanding of the selective pressures acting on early crop domestication in Western Asia, combining elements of experimental plant ecology, molecular biology, archaeobotany and GIS analysis. Through collaboration between

keys


researchers at the Department of Archaeology, the Department of Animal and Plant Sciences and the School of einkornMathematics and Statistics at the University of Sheffield, and the Faculty of Life Sciences at the University of Manchester, various aspects of the adoption of agriculture in the early Holocene will be investigated, with an emphasis on evolutionary changes in crop plants associated with domestication. The archaeobotanical and statistical work focuses on detailed metrical analysis of cereal grains and chaff recovered from archaeological sites in the study region, with the aim of establishing whether there are notable differences in examples of the same species (e.g. einkorn, initially) from different sites. This work is linked closely with, and builds upon, the Origins of Agriculture project, for which a database of sample-level archaeobotanical measurements from sites in Western Asia has been compiled; the database is being used in conjunction with ArcGIS 10 to identify pre- and early Neolithic sites with sufficient quantities of suitable archaeobotanical material for analysis. Experimental charring of cereal plant parts is also being carried out so that the impact of charring conditions on the morphology of grain and chaff can be assessed.


In order to investigate the effects of late-glacial and early Holocene environmental conditions on plant growth rates and yields, and their significance in terms of early selection and cultivation of crops, researchers in the Department of Animal and Plant Sciences will carry out growth experiments using plants that were present in the study area when agriculture was adopted, including wild grasses that are not known to have been domesticated and crop progenitors. The first phase of work is underway, examining the impact of varying carbon dioxide levels on growth rates.

dnaDNA analysis at the University of Manchester (Life Sciences) is being employed to investigate the timing and order of selection of traits associated with domestication in early crops, such as indehiscence and increasing seed size. Initially, the theory that a genetic ‘bottleneck’ occurred during the domestication process will be tested, as this will be important in determining the direction in which later analyses proceed.

Funded by: ERCerc-logo

Grant period: 2011 – 2014
Grant holders: Prof. G. Jones, Dr. M. Charles (Sheffield, Archaeology), Dr. C. Osborne, Prof. M. Rees (Sheffield, Animal and Plant Sciences), Dr. N. Fieller, Dr. E. Stillman (Sheffield, Mathematics and Statistics), Prof. T. Brown (Manchester, Life Sciences)
Researchers: Dr. E. Forster (Sheffield, Archaeology), Dr. G. Frenck (Sheffield, Animal and Plant Sciences), Miss S. Bunning (Manchester, Life Sciences)

Relevant publications