FascinatingI assumed this from NatJ explanations, but I haven't got a clue about it. I definitely may have gotten it wrong.
Edited: this article gives a few interesting answers in the introduction : https://www.google.com/url?sa=t&sou...QQFnoECCAQAQ&usg=AOvVaw2AOj3Ytyy8kb4R_gKvSmjd
Does seem to be a dominant gene.