For whatever it’s worth, I went to a conservative Christian college (Grove City), and one of the science professors there gave a very cogent presentation on this topic. The gist of it was that no honest examination of the evidence points to a so-called “young earth,” a literal six-day creation or the coexistence of humans and dinosaurs.
This was a very smart man, a devout Christian and an all-around nice guy, but I remember the annoyance and embarrassment in his voice when he spoke of some of the more contrived “theories” hatched to reconcile scientific evidence with biblical literalism: for instance, the notion that God created the earth and its geological formations to “appear” billions of years old. My prof said essentially that the God Christians believe in does not aim to deceive and that a notion like this is an insult to everyone’s intelligence.
I’m not scientist myself (far from it), so this is just my prof’s two cents.
So if God created Adam as a full grown man this was meant to deceive? If God did create Adam as a mature man, why couldn't he do the same with the universe?