Genome sequencing shows maize adapted to highlands thousands of years ago
Genome sequencing shows maize adapted to highlands thousands of years ago
August 4, 2017 by Bob Yirka
(Phys.org)—An international team of researchers has found evidence showing that maize evolved to survive in the U.S. southwest highlands thousands of years ago. In their paper published in the journal Science, the group outlines their genomic study, which revealed the genetic changes that allowed the plant to live in the harsher environment.
Maize, more commonly known as corn, originated in Mexico and made its way to what is now the southwestern U.S. approximately 4,000 years ago. In doing so, it quickly became one of the most important crops in the North America. But, as the researchers note, it did not make its way into the highlands for another 2,000 years, a development that has puzzled archaeologists. To better understand why the delay occurred, the researchers studied samples of 2,000-year-old maize cobs found in a cave back in the 1970s in Utah's highlands.
To learn more about its physical attributes, they sequenced the genome of 15 of the cobs and compared the results to other maize lines. They report that the maize plants around the cave area were not as tall as other maize plants that grew at lower elevations and that it had more branches—in short, they describe the plants as more bushy than other maize plants, a trait that allowed the plant to thrive in colder places. They also found evidence that the plant flowered earlier than most other maize plants, an attribute that would help it produce seeds before the earlier frost at higher elevations.
As the plants evolved to withstand the harsher environment, early people living there began to introduce maize into their diet, just as other early people had done in the southwest lowlands thousands of years earlier.
Read more at: https://phys.org/news/2017-08-genome-sequencing-maize-highlands-thousands.html#jCp