April 3, 2012
Ancient Egyptians May Have Domesticated Native Cotton
Scientists have studied 1,600 year old cotton from the banks of the Nile and have found what they believe to be evidence of early crop evolution. These findings are the first to find this kind of evolution in a major crop group, especially since plant domestication has a relatively short history.
The findings offer an insight into how crop evolution works as a part of general agriculture. They might also help scientists and researchers better equip today´s crops as they face major environmental challenges, such as climate change and water shortages.The study was funded by the NERC and is published in the journal Molecular Biology and Evolution.
The researchers, led by Dr Robin Allaby from the School of Life Sciences at the University of Warwick, studied the remains of ancient cotton from the Upper Nile in Egypt, sequencing their DNA using high throughput technologies.
Until now, these technologies had not been used to study the genetics of ancient plants, nor had it been used in archeological applications in such hot countries.
The team took samples at Qasr Ibrim, Egypt, 40 km from Abu Simbel and 70 km from the modern Sudanese border on the East bank of what is now Lake Nasser.
In addition to the Egyptian samples, the team also took 800-4,000 year old samples from Brazil and Peru.
The test results showed the Egyptian cotton, identified as G. herbaceum, provided significant evidence of genomic restoration between ancient and modern varieties. This came as a surprise to the researchers, as the cotton had undergone such reorganization over such a short time, relatively speaking, of a millennia and a half.
The samples found in South America, however, did not show such drastic differences on the genomic level, despite their being separated by more than 2,000 miles and 3,000 years.
These sort of results show the plants underwent periods of punctuated evolution. While the plant underwent some periods of little change, there were other times in its history where it underwent rapid change.
According to a University of Warwick press release, Dr. Allaby said, “We think of evolution as a very slow process, but as we analyze more genome information we can see that there´s been a huge amount of large-scale proactive change during recent history. “Our results for the cotton from Egypt indicate that there has been the potential for more adaptive evolution going on in domesticated plant species than was appreciated up until now. “Plants that are local to their particular area will develop genes which allow them to better tolerate the stresses they find in the environment around them.”
Dr. Allaby said the findings suggest plants will develop particular genes depending on their surrounding environment. This sort of genetic adaptation allows the plant to better tolerate the stresses surrounding them. One example, according to Dr. Allaby, are the cotton samples taken from Egypt.
“It´s possible that cotton at the Qasr Ibrim site has adapted in response to extreme environmental stress, such as not enough water.”
This research also benefits archeologists, as it proves the ancient Egyptians domesticated a cotton crop native to Africa. Until now, archeologists thought they may have domesticated an Indian variety of cotton.
“The presence of cotton textiles on Egyptian and Nubian sites has been well documented but there has always been uncertainty among archaeologists as to the origin of these,” said Allaby.