A tale of terroir: Porcinis evolved to the local environment – @theU

Creationists should note here that the scientists who produced the report see this 'problem' entirely within the Theory of Evolution by Natural Selection (TOE). The strangeness is not a problem for the theory but an example of how a fundamental principle of the theory - environmental selection - operates in North America.
The 'problem' is that while Boletus edulis exists in North America as a number of different varieties and genetically distinct populations, probably caused not so much by geographical isolation as environmental adaptation, albeit with regular ingress from surrounding populations, In Eurasia, a single genetic lineage dominates from Spain to Georgia to Scandinavia, so the interesting question is why does is the species genetically continuous in Eurasia but fragmented in North America; what is the difference between the two landmasses that causes this difference.
The Eurasian and North American populations are believed to have become separated during a period of climatic change and the onset of glaciation, 1.62–2.66 years ago. Attempts to segregate populations of Boletus edulis into distinct species based on phenotype have foundered on the genetic evidence, illustrating how small genetic differences can give large phenotypic differences and how a species in the process of speciating passes through a stage at which the diverging populations have not diverged sufficiently to qualify as new taxons because the practice of taxonomy tries to fit a continuous process into a series of distinct events.
The 'problem' is the subject of a free access paper in the journal New Phytologist by Keaton Tremble and Bryn T. M. Dentinger from Utah University, Utah, USA. together with J. I. Hoffman from Bielefeld University, Germany, and was described in a University of Utah press release: