how?
The genes control the growth and thus flower production
I didn’t think I needed to explain further but clearly I do. We all know that genes control everything in living organisms but most do not switch genders. So, yes there are genes, but HOW do they cause that in walnut trees and virtually nowhere else. What’s different? The article says it’s like the X & Y chromosomes in humans but, with the exception of democrats, humans do not switch between male and female and back again.
So, again I ask, HOW do they switch back and forth?