Everything we 'know' we have been told by someone else. And someone else has, in turn, been told by someone else and so on ad-finitum.
We can conjecture, look at things and make conclusions. We can debate and come to some sort of understanding. But all this is coloured by our conditioning and desires. Which is why there are wars and so many different ideologies of one sort or another.
We all have our drum to bang and trumpet to blow - "I am right listen to me or be killed" or some such.
The truth is no-one knows; by which I mean really KNOWS 100% because we were not there 6000; 10000 or a million or more years ago.
Calling "I read it in a book (so it must be true)"; "I read it in an encyclopeadia (so it must be true)"; "I saw it on a documentary (so it must be true)" is meaningless. They are someon else's ideas and thoughts and you have no idea if they are true. Look at the news (if you do) how much is really true?
And really, what does it matter what happened billions of years ago or last week? There is no past there is no future; there is just the now; everything is just memory - even what we call the future is the past; because we think about it and thoughts have to have happened and so are from the past.
Many people live their lives in one of two places, the past or the 'future' and miss out on the NOW. The WT is always to the future and people miss their live totally rushing for some will-o'-the wisp furtur event when everything will be all right. Others stay morbidly dwelling on what happened and might have happened but didn't and also miss being in the NOW.
Whatever your next step is; it starts from NOW.