there is a deep genetic reason why in most mammal and bird species it is the male that spends most of the metabolic cost to developing traits whose primary value is to compete for and attract females for mating, rather than the other way around.
The reason is male sex chromosome is inherited purely from the father and does not undergo recombination with the mother’s genes. Therefore traits encoded in the male sex chromosome are all expressed, and not suppressed by a different copy of the same genes. So it is more efficient to weed out bad genes from the gene pool by challenging the male to undertake metabolically expensive tasks than it is by challenging the female, because a female who passes such challenges and is outwardly without genetic short comings is more likely to actually have hidden, bad, but unexpressed copies of genes that she can pass onto her offspring.
The reason is male sex chromosome is inherited purely from the father and does not undergo recombination with the mother’s genes. Therefore traits encoded in the male sex chromosome are all expressed, and not suppressed by a different copy of the same genes. So it is more efficient to weed out bad genes from the gene pool by challenging the male to undertake metabolically expensive tasks than it is by challenging the female, because a female who passes such challenges and is outwardly without genetic short comings is more likely to actually have hidden, bad, but unexpressed copies of genes that she can pass onto her offspring.
