Oryza glaberrima massive paleolakes in what is now the Western Sahara. As the climate dried, the wild rice retreated and probably became increasingly domesticated as it relied on humans for irrigation. Rice growing in deeper, more permanent water became floating rice. It is believed to have been domesticated 2000–3000 years ago in the inland delta of the Upper Niger River, in what is now Mali. It then spread through West Africa. It has also been recorded off the "east" coast of Africa, in the Zanzibar Archipelago. Wild rice seedheads shatter, scattering the rice grains to seed the next generation. Domestic rice does
Plant genome assembly products were used to clone remaining gaps, and YACs allowed the characterization of telomere sequences. The resulting sequenced regions were 115.4 Mb of the 125 Mb predicted size of the genome and a total of 25,498 of protein-coding genes. To sequence and assemble the genome of Oryza Sativa (japonica), the same strategy was used. For Oryza Sativa a total of 3,401 mapped clones in a minimum tiling path were selected from the physical map and assembled. One of the most important crops in the world, maize (Zea mays), is the last plant genome project primarily based on Sanger BAC-by-BAC strategy.