Consider a comparison of two cladistic analyses aimed at reconstructing the phylogeny of a particular set of mammalian species. One of these studies used Y-chromosome sequences and the other used mtDNA sequences, and both studies successfully avoided the problems associated with homoplasy. Explain why the species trees estimated by these studies would likely be very similar, despite the fact that these data sets were generated by lineage histories that do not contain ANY individuals in common (Y-chromosomes evolve thru males only, while mtDNA evolves thru females only)?