With common beans you oftentimes find traits mirrored in populations on both sides of the Altantic. Exceptions to this generalisation are the shiny 'greasy' beans from the Appalachians and these curved Kipfler beans which appear to be exclusively clustered in regions around the Alps.
Interestingly there doesn't appear to be any varieties with this phenotype from the Americas, and they are absent from Europe more broadly, except in this limited area. What piques my interest is the obscure reason as to
why?
Did the trait arise in the region? Is there a genetic linkage between the genes for curved pods and a particular adaptation that makes them thrive in a that particular climate? Why did it not travel further? Were they selected simply because they satisfied the human penchant for the aesthetically appealing, or did they serve some other purpose before the rise of modern agriculture? Are curved pods a chance mutation of a single gene, or is pod curvature something controlled by multiple genetic factors that take generations of rigourous selection to reach such extremes?

Alas, I'm now hypnotised by the spirals

I need answers, but I do not need another bean project