The greatest challenge to the intellect is whether or not one can begin to question his own most deeply held beliefs.
Ant the ability to suspend disbelief.
For the naturalist, this would mean taking a new, skeptical approach to things like whether there might be holes in the idea that natural selection and speciation are truly consistent with empirical reasoning.
And whether there might be any flaws in the premises needed to have total faith in the accuracy of radiometric dating.
"Whether there might be holes in the idea" is not a tool of formal scientific methodology.
Instead, it belongs in the intuitive "brain-storming" stage prior to proposing a new hypothesis.
So it's on the path by which a scientist goes from data-analysis to formally proposing a testable new hypothesis.
And let me suggest to you: for every one new hypothesis proposed -- a hundred, or a thousand, likely ideas get ginned-up, kicked around and knocked down because they don't stand up to normal tests of reasonableness.
Ideas which make it through the brain-storming phase to become formal hypotheses must next be tested to see if they can be falsified.
Hypotheses which pass their initial falsification tests are graduated up to the level of "theory", meaning a confirmed hypothesis, pending further tests.
And that's as high as it can go, scientifically.
There is no higher category for a scientific idea, short of it becoming an observed fact, which is often impossible.
So evolution is a confirmed hypothesis -- a theory.
Historically, there have been other related hypotheses proposed and confirmed, which clarify the evolutionary processes of descent with modifications and natural selection.
There were also, long ago, competing hypotheses under different names, which have long since been falsified and so consigned to the "dustbins of history".
But there are no recent scientific hypotheses which would if confirmed overthrow the basic evolution idea.
All such suggestions have been religion-based, and not even testable, which means they violate science's first principles, including, "natural explanations for natural processes".
That's why they aren't taken seriously by most scientists.
reasonisfaith: "And whether there might be any flaws in the premises needed to have total faith in the accuracy of radiometric dating."
Science is never about "total faith" in anything.
Even where science is used to launch human beings into outer space, the science is tested, tested and retested.
Anyone who drives a vehicle knows it is only as reliable as its last service checkup, and even then not always.
But radio-metric dating is not just one tool, it is about two dozen different methodologies, most of which overlap with others and can therefore be used to confirm or falsify results of any one test.
Furthermore, there are totally independent measurements of light-year distances to stars and galaxies throughout the Universe, which show the most distant stars over 10 billion light years away, and our own Milky Way Galaxy 100,000 light-years across, takes 200 million years per rotation and includes as its oldest stars 13 billion years old.
That same science dates our Sun as 4.6 billion years old.
All of that independently places earth-based radiometric age dating within its larger context, and helps to confirm the age numbers.