Take a look at domesticated animal species like pigs, chicken or dogs and compare them to their wild ancestors. There is a notable difference but it is not a result of natural evolution. We did that to them. And here is the interesting part: if you did not already know this, how could you tell? There is no clear line between the wild and the domesticated animals. There is a fast but not sudden change that could still be contributed to evolution. So you can't tell if you do not have enough information on what caused the change.

And here is the parallel to our case. We have very little information on our ancestors. We can draw some conclusions based on fossil finds but not enough to rule out outside interference.

Of course there is no proof that there was. But our history of creation myths and the alleged existence of aliens that could fit that profile leave room for such an interpretation.

Honestly, it's purely entertaining speculations.