CDZ Birds are ZW, Mammals are XY in Sex slection

[william the wie]

Why do women act and post like humans are birds, not mammals? Women normally do well in biology and that is the science they are most likely to study so why pretend ignorance of this fact in several active threads and if not pretending then here is a simple explanation.

Since the default gender in birds is male, in mammals the default gender is female. The default gender gets the greater genetic return in all species that have sex selective Chromosomes. Please stop resorting to counter-factual arguments, ladies.