I'd assumed they were talking below freezing!the genetics in that article were way beyond my ken too, but that seems to me to be the gist of it. On the other hand, I consider a temperature of about 20 C perfect sightseeing weather - not too hot for a lot of walking, not too cold demanding lots of layers - so I'm not sure I'd classify this as a 'cold' climate adaptation![]()
(materials and methods section: "the conditions for normal growth and development were temperatures, on average, of 20 °C (18–23 °C) versus the generally accepted 30–33 °C")