I am revising my biology after a good few years.
I was thinking that as a female has two X chromosomes, and a male has an X and a Y chromosome. This must mean (given approx the same number of females and males over evolutionary timescales) that there have only been 25% Y's as compared to 75 X's . Does this mean that as there have been fewer instances of X chromosomes there has been less opportunity for natural selection to work its wonders?
Am I making a blunder somewhere?
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