[pron]

> That, as I said, is not likely to be true.

I think it's by far the likeliest explanation given everything we know of human societies and human history (i.e, as a general rule, almost everything is fluid). Moreover, it's the safest: if, as a result of such under-representations, certain groups have less power in society, it's unreasonable not to try to fix it. If people get sick and you don't know if the disease is curable or not, the far safer (and more ethical) assumption is that it is. Both assumptions are not symmetrical.