I've been reading Adam, the Fall, and Original Sin, Hand Madueme and Michael Reeves, eds. It's an uneven collection of essays. For now I'd like to focus on the scientific question. Mdueme puts his finger on one difficulty with theistic evolution and/or old-earth creationism:
One weakness, however, is the potential of an Adam-of-the-gaps fallacy. Paleontology, paleoanthropology, and associated disciplines are judged basically reliable as sources of truth and they provide the main story; the task of the theologian is then to find a way to identify the historical Adam within that story (237).
That certainly looks like an ad hoc amalgam of two divergent paradigms. Young-earth creationism doesn't have that problem. But it trades that problem for a different problem: challenging the science that drives old-earth creationism and theistic evolution.
1) Let's some general observations about the scientific method. All things being equal, an operating assumption of scientists is that the past produces the future. Antecedent conditions effect subsequent conditions.
The same physical causes produce the same physical effects. In that respect, past and future resemble the present. Therefore, taking our knowledge of the present as a frame of reference, we can extrapolate forward and backward.
For instance, dating techniques presume constancy in the rate of natural processes. Likewise, evidence for human evolution based on population genetics (e.g. the "bottleneck") presumes constancy in the rate natural processes.
Physical causes operate with mechanical regularity. They do whatever they were programmed to do–no more and no less.
2) Up to a point, that's a reasonable assumption. And it has some theological warrant. We call this ordinary providence.
So, for instance, a Christian goes to the doctor, under the assumption that diseases typically have physical causes which are physically treatable.
3) However, that's qualified. If nature takes its course, a terminal cancer patient will die.
Sometimes, however, a terminal cancer patient undergoes remission in answer to prayer. In that situation, past conditions don't produce or predict for future conditions. In that case, the outcome doesn't belong to the chain of events (i.e. physical causation).
That's because physical causes are not the only causes. Not even the only causes of physical effects.
That, however, interjects a degree of unpredictability into the presumption of continuity between past, present, and future.
The history of the world contains singularities. Outcomes discontinuous with prior states. Indeed, the world began with a singularity: fiat creation.
In addition to that macrocosmic singularity, the history of the world is punctuated by microcosmic singularities. Miracles which bypass the causal continuum.
All things being equal, linear extrapolations from the present into the past are reasonable. But that means bracketing kinds of mental agency which produce immediate physical effects. By "immediate," I mean apart from an intervening physical medium. Candidates include God, angels, demons, ghosts, and human psi.
Because God usually operates behind the scenes, working via physical means, it's easy to ignore God when we do science. God is like a necessary background condition. Unobtrusive. We don't expect God to intervene at any particular time and place, so our default policy treats the course of nature as the norm.
But it's precisely because divine intervention is unpredictable that scientific prediction or retrodiction is unreliable to some imponderable degree. We can't quantify when or where God (or other agents) will interrupt the course of nature. That interjects an unstable element into historical reconstructions. The scientific method is arbitrary in that respect. It's true–except when it's false.
That's why pious Christians have a two-track policy. We presume ordinary providence, but we also pray.
Nature is like a machine. It has a default setting. But it also has a manual override. God can break the cycle in answer to prayer.
4) Moreover, this isn't just hypothetical. There's more to human history than ordinary providence. There's special providence. And miracles. And answered prayer. And the occult.
Let's consider some of the putative evidence for human evolution:
i) Comparative anatomy. There are fossil remains of creatures that have a humanoid appearance. Hands. Skulls. Bipedalism.
There are, however, problems with that line of evidence:
a) Ostriches and kangaroos are bipedal. But that doesn't relate them to man. Some bats, marsupials, and chameleons have opposable digits. But that doesn't relate them to man.
b) Moreover, bipedalism is unrelated to cognitive ability.
c) Modern humans coexist with apes and monkeys. We share morphological similarities, yet there are drastic cognitive differences. Why think fossil "hominids" must be anything other than extinct apes and monkeys?
ii) Apropos (i), some "hominids" use tools, yet that, by itself, isn't probative. There are animals that use tools, viz. crows, sea otters, green jays, trapdoor spiders, and woodpecker finches.
Or take beehives and spiderwebs. If apes and monkeys did that sort of thing on a larger scale, Darwinians would chalk it up to simian brainpower.
Most fossil artifacts aren't uniquely human in that regard. Cave paintings and musical instruments are unmistakably human. But much of the other "evidence" is quite ambiguous.
iii) Another line of putative evidence is the alleged correlation between cultural evolution and encephalization. That, however, is tricky to parse.
a) To begin with, the relationship between minds and brains is somewhat baffling. For instance:
b) Knowledge is cumulative. Knowledge builds on knowledge. And the rate of progress can accelerate. We see that in the rapidity of technological advances. It takes a long time to get to the tipping point. After that, the rate of progress picks up pace. Crossing that threshold is the hard part.
Gen. Curtis LeMay reputedly said we should bomb the Viet Cong back to the Stone age. Suppose something like that happened to human civilization.
As long as modern know-how survived, we could probably get back to where we were in a few decades. If, however, the knowledge was lost or forgotten, then it would take centuries or probably millennia to start from scratch.
You can't have a Newton without a Kepler. You can't have an Einstein without a Riemann or Mach. If Einstein was born before Riemann or Mach, he wouldn't develop Relativity.
And it's a matter of space as well as time. If Linus Pauling, Paul Dirac, or Claude Shannon were born in the Amazon jungle, and never made contact with the outside world, their genius would go to waste.
In addition, some scientists, like Newton or von Neumann have a unique skill set. If we had to start all over again, you wouldn't have a Newton, Einstein, or von Neumann. You'd have other geniuses with different skill sets.
Although we might make the same scientific breakthroughs, we wouldn't make them in the same order. It might be sooner or later. You might have scientific theories which overlap with the theories we have, but the pieces would be rearranged. The pieces would come together in different ways at different times.