|Out of universe information|
The Dalerans are a fundamentally pre-industrial human race in the Pegasus galaxy. Despite their limited technology, many of their people possess the Ancient Technology Activation gene as Dalera, an Ancient, fell in love with a human native of the planet, her descendents becoming known to the population as the Chosen for their ability to use Ancient technology to protect the general populace, most notably the Shield of Dalera, which deactivated all technology in its vicinity.
However, by the time Major John Sheppard's team made contact with the planet, the Chosen were dying out due to their elitist views having resulted in extensive inbreeding and the subsequent weakening of the Ancient gene, prompting one of the Chosen to secretly sneak out of the castle and engage in dalliances with the local women, resulting in a new generation of Chosen that were discovered thanks to the analysis of Dr. Carson Beckett, leaving the Atlantis expedition with hope that the Dalerans would re-evaluate their society. (ATL: "The Chosen")