research worker sequencing the desoxyribonucleic acid of ancient corn from dozens of archaeologic sites have found that early North Americans channel Zea mays from Mexico into the southwestern U.S. on two unlike route at different times : One took the gamey route , the other took the low route , thousands of years later . Thefindingswere publish this hebdomad in the first - ever issue ofNature Plant .
We know that corn ( Zea maysssp . Mays ) was domesticated from a wild Gunter Wilhelm Grass called teosinte found in central and southerly Mexico , but its journey into what ’s now the American Southwest has been up for debate . equate the DNA of modern crop with their wild contemporaneous cousins would n’t take into account the transitional plants along the way between those eat by early human ascendent and those in the markets and county bazaar today .
For the whole account , a heavy international team led byRute da FonsecaandThomas Gilbert from the University of Copenhagensequenced the DNA of ancient corn — include long - disappeared varieties — from 28 archaeological sites in the Southwest and Mexico , which were dated from 5,910 to 740 years ago . About a dozen of their sample came from excavations of multiple stratigraphic layers of the Tularosa Cave in New Mexico , allow them to look at genes from different time periods . The squad then compared these termination with modern corn , as well as genetic material from four museum specimen of ancient Chilean corn .
The first stage of maize first appearance into the Southwest , they found , pass off through the highlands of the Sierra Madres about 4,000 class ago . That was follow by a factor flow from a lowland route along the Pacific coast 2,000 age afterwards . “ When reckon together , the results suggest that the maize of the U.S. Southwest had a complex blood line , ” written report co - authorJeffrey Ross - Ibarra from UC Davissays in anews release .
to boot , the team find evidence of evolutionary pressure give to the plant by human migrations and the diverse tastes of various finish . These included version for growing in wry climate , as well as genes responsible for changes in amylum and sugar penning , which made it potential to educate odorous corn .
“ It ’s only really recently that maize has become what you would know as Indian corn if you went to a market store,”Gilbert tells Science . In the evolution of corn on the cob , the first thing farmer breed out of ancient maize was an annoying feature prognosticate “ smashing , ” where wild plants scattering seed every which way . Then , over several centuries , farmers bred drouth - resistant maize . at long last , only about a thousand years ago , came corn with improve nutritional depicted object and easy - to - physical process heart that made making delicacy like tortillas easier .
