Yeah, but it didn't matter either. It wasn't until we stopped roaming and stayed out which led to thibkibg of land in terms of property, which led to inheritance that paternity became an issue.

Before that, men invested more heavily in the children of their hearth or their mate because of proximity, but all children of the tribe were seen as theirs and they were collectively responsible for.

This was important to our survival as a species.

As a man, if you died you'd want the security of knowing that the other men of the tribe wouldn't kill your children to take your mate. You'd want to know that they'd invest in seeing those children to adulthood.

Plenty of women are, at least partially, raising children who are not theirs. Grandmothers, stepmothers, aunties, etc. And always have. Because you never know when something might happen to you that leaves you temporarily or permanently unable to parent. If you can't have some basic level of assurance that someone will step up into that role....what's the point of having children?