HHMI BioInteractive – The individual X and Y chromosomes are really a pair that is unique More About Evolution of The Y Chromosome One other chromosome pairs, called the autosomes, seem to be identical twins; they’ve been superficially indistinguishable. In comparison, the X and Y chromosomes seem to be greatly not the same as each other. Exactly why are the intercourse chromosomes therefore various? Exactly just exactly How did they have…