Columbian exchange As the demand in the New World grew, so did the knowledge on how to cultivate it. The two primary species used were oryza glaberrima and oryza sativa; originating from West Africa and Southeast Asia respectively. Slave holders in the New World relied upon the skills of enslaved Africans to further cultivate both species. . North and South Carolina were key places where rice was grown during the slave trade, and islands of the Caribbean like Puerto Rico and Cuba were equally great centers of production. Enslaved Africans brought their knowledge of water control, milling, winnowing, and other general agrarian
Helitron (biology) Helitron (biology) Helitrons are one of the three groups of eukaryotic class 2 transposable elements (TEs) so far described. They are the eukaryotic rolling-circle transposable elements which are hypothesized to transpose by a rolling circle replication mechanism via a single-stranded DNA intermediate. They were first discovered in plants ("Arabidopsis thaliana" and "Oryza sativa") and in the nematode "Caenorhabditis elegans", and now they have been identified in a diverse range of species, from protists to mammals. Helitrons make up a substantial fraction of many genomes where non-autonomous elements frequently outnumber the putative autonomous partner. Helitrons seem to have a major role