stylistic:tone, structural:scholar_edition, quality:correction
History

Quinoa is an allotetraploid plant, containing two full sets of chromosomes from two different species which hybridised with each other at one time. According to a 1979 study, its presumed ancestor is either Chenopodium berlandieri, from North America, or the Andean species Ch. hircinum, although more recent studies, in 2011, even suggest Old World relatives. On the other hand, morphological features relate Ch. quinoa of the Andes and Ch. nuttalliae of Mexico. Some studies have suggested that both species may have been derived from the same wild type. A weedy quinoa, Ch. quinoa var. melanospermum, is known from South America, but no equivalent closely related to Ch. nutalliae has been reported from Mexico so far.

Studies regarding the genetic diversity of quinoa suggest that it may have passed through at least three bottleneck genetic events, with a possible fourth expected:

Over the last 5,000 years the biogeography of Ch. quinoa has changed greatly, mainly by human influence, convenience and preference. It has changed not only in the area of distribution, but also in regards to the climate this plant was originally adapted to, in contrast to the climates on which it is able to successfully grow in now. In a process started by a number of pre-Inca South American indigenous cultures, people in Chile have been adapting quinoa to salinity and other forms of stress over the last 3,000 years. Quinoa is also cultivated, since an early date, near the coast of northern Chile, where it was grown by the Chinchorro culture. Ch. quinoa was brought to the lowlands of south-central Chile at an early date from the Andean highlands. Varieties in the lowlands of south-central Chile derive directly from ancestral cultivars which then evolved in parallel to those of the highlands. It has been suggested that the introduction of Ch. quinoa occurred before highland varieties with floury perisperm emerged. There are wide discrepancies in the suggested dates of introduction, one study suggests c. 1000 BC as the introduction date while another suggests 600–1100 AD. In colonial times the plant is known to have been cultivated as far south as Chiloé Archipelago and the shores of Nahuel Huapi Lake. The cuisine of Chiloé included bread made of Quinoa until at least the mid-19th century.

In Chile it had almost disappeared by the early 1940s; as of 2015 the crop is mostly grown in three areas by only some 300 smallholder farmers. Each of these areas is different: indigenous small-scale growers near the border with Bolivia who grow many types of Bolivian forms, a few farmers in the central region who exclusively grow a white-seeded variety and generally market their crops through a well-known cooperative, and in the south by women in home gardens in Mapuche reserves.

When Amaranthaceae became abundant in Lake Pacucha, Peru, the lake was fresh, and the lack of Amaranthaceae taxa strongly indicates droughts which turned the lake into a saltmarsh. Based on the pollen associated with soil manipulation, this is an area of the Andes where domestication of C. quinoa became popular, although it was not the only one. It was domesticated in various geographical zones. With this, morphological adaptations began to happen until having five ecotypes today. Quinoa's genetic diversity illustrates that it was and is a vital crop.

Andean agronomists and nutrition scientists began researching quinoa in the early twentieth century, and it became the subject of much interest among researchers involved in neglected and underutilized crop studies in the 1970s. The grain, however, has received much less attention than crops like maize or wheat.

Particularly for the high variety of Chilean landraces, in addition to how the plant has adapted to different latitudes, this crop is now potentially cultivable almost anywhere in the world.