You're now speaking for yourself. The biblical literalists here on FR, and elsewhere, clearly state that it's the age of the earth.
BTW, the 6000 figure isn't necessarily incompatible with Darwin's theory, even though Darwin expressed no interest whatever in "souls."
But, stipulating said ensoulment, are we all descendants of Adam, or can souls be laterally transferred? You must be aware human population genetics are incompatible with common ancestry as recent as 6000 years. Aborigines have been in Australia for far more than 6000 years.
I was following the great Jewish scholars here: Maimonides, et al., are my authorities on this point. I figure they're the "real experts" on the Old Testament. Others are free to consult other sources if they wish.
...stipulating said ensoulment, are we all descendants of Adam, or can souls be laterally transferred?
Yes, but perhaps not literally; and No.
You must be aware human population genetics are incompatible with common ancestry as recent as 6000 years.
If there is common ancestry, it surely dates back farther than 6000 years. But the issue is not common ancestry; it's when the first fully human being was ensouled by God -- which is the sine qua non of man's full humanity.
But now were are doing something here that Alamo-Girl cautioned against: mixing science and philosophy/theology. What I've said above indicates some of the profound differences between the two. But such distinctions tend to get lost on these evolution threads. So maybe we ought to quit while we're ahead?
In the end, the two disciplines are the two legs we stand on.