There are rocks and bones and tools.
But your point is valid, if you go back far enough at some point how things got started is an article of faith.
BTW, even Darwin avoided that question, his book 'On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life' specifically does not address the origin of life itself, only how existing lifeforms adapt to their changing environments over time.
Science addresses how something happens/happened. Religion addresses why...
Bones, stones and tools don’t mean much if they aren’t properly understood. :)
What I mean by this is that it is generally taught, that man’s existence can almost be traced by a linear graph, from the jungles of Africa to a paleontological and brutish existence, eventually our current existence which is the most advanced today.
In truth, there is plenty of evidence that shows our existence has gone up and down. We’ve gone from periods of primitiveness to advancement and back to primitiveness and back to advancement.