An international group of scientists have analysed the DNA of 6,000 year old barley finding that it is remarkably similar to modern day varieties.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/ancient-barley-dna-gives-insight-crop-development
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/bbc-uk
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/agriculture
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/food-crops
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/agricultural-research
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/genetic-engineering
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/farmers