Short answers, pulled from the story.
The potato was first domesticated by pre-Columbian farmers around Lake Titicaca, in present-day southern Peru and northwestern Bolivia, about 7,000 to 10,000 years ago. It was domesticated from a wild species in the S. brevicaule complex. The earliest archaeologically verified potato tuber remains date to 2500 BC at the coastal site of Ancon in central Peru.
The Spanish introduced the potato to Europe in the second half of the 16th century, following the Spanish conquest of the Inca Empire, as part of the Columbian exchange. European mariners then carried it to ports throughout the world. After 1750 it became an important food staple and field crop in Europe.
The Great Irish Famine followed crop failures in 1845 caused by late blight, a disease from the oomycete Phytophthora infestans. It spread rapidly through poorer communities of western Ireland and parts of the Scottish Highlands. The crop was vulnerable because the limited number of varieties first introduced left it with little genetic diversity.
Potatoes contain glycoalkaloids, mainly solanine and chaconine, which protect the plant from predators and are concentrated in its aerial parts. Tubers are normally low in these toxins, but exposure to light makes them turn green and develop solanine. Breeders try to keep glycoalkaloid levels below 200 mg/kg.
In 2023, world production of potatoes was 383 million tonnes, led by China with 25% of the total, with India as a major secondary producer. New Zealand farmers have demonstrated some of the best commercial yields in the world, between 60 and 80 tonnes per hectare.
There are some 5,000 potato varieties worldwide, with 3,000 of them in the Andes alone, mainly in Peru, Bolivia, Ecuador, Chile, and Colombia. Following centuries of selective breeding, over 100 cultivars might be found in a single Andean valley.
DNA analysis shows that more than 99% of all current potato varieties are direct descendants of a subspecies that once grew in the lowlands of south-central Chile. This challenged the earlier belief that most cultivars derived from a single origin in southern Peru and extreme northwestern Bolivia.