KB -

Not necessarily true, and in the case of the actual "tracings" not at all true. There were some prior discussions, with links to articles that should make the difference clear.

The MRCA(Eve) is the one for whom all her sisters' (and cousins etc.) descendants became extinct, but some of hers survived.

The MRCA(Adam) is the one for whom all his brothers' (& etc.) descendants became extinct, but some of his survived.

In a sense, it's more a matter of how recently all the other lines were wiped out, than a matter of survival of the line that is traced back.

As a trivial - NOT necessarily the only - example of how there could be a difference, conquering armies frequently killed all the males but enslaved (and bred) all the females , so the rates of extinction of a given hereditary line differed significantly for male ancestors and for female ancestors. We're all descended from ancient kings, 'cause the politicians always weasel their way out and survive.(?)

John