7. If your answer to 1-5 is "we don't care, scientists who think this shows an old earth and common descent in primates are devotees of scientism and we don't share their metaphysical assumptions", exactly how does this imply materialism and what specific metaphysical assumptions aren't shared?
Firstly, age aside, it doesn't show common descent. Nothing you've cited and nothing to be found in the annals of science logically implies it. It's only a "preferred" explanation, because after a lot of stop-gaps and leaps for steps which have no empirical verification and no provided explanation, cue the God-of-the-gaps of theistic-evolutionary pseudoscience, it's most appealing to some people's subjective sense of what is "reasonable" and "likely". Dependency graphs can model known relationships between species and genetic information flow, and they do, by statistical measures, such a good job of it in comparison with common descent models that the probability of latter providing the correct "explanation" is practically zero.
Assumptions? Oh, those. Where does one even begin? This is hardly a comprehensive and deductively structured list, and maybe not every one applies, but off the top of my head, before I tire of this:
The ontological subject-object distinction is meaningful and an independent objective world exists.
An objective material world exists.
This world is distinct from the experience of it.
It is experienced only mediately and only by a particular state of consciousness, the rest being imaginary.
These others, like the dream space, therefore, do not provide a picture of fundamental, objective reality.
"Empirical science" provides knowledge of this fundamental, objective reality.
The experience of normal waking consciousness is an the indirect experience of this objective material world mediated via sensory organs and the brain.
This objective material world is a cause of the existence, if not of the subject, then certainly the phenomenal content of his experience of it.
This objective material world is bound to follow mechanical physical laws.
These physical laws do not change.
These laws are discoverable.
Inductive inferences from past events are valid.
This objective physical world is really geometrically structured.
This space is a metric space
Realism with respect to the objects of atomistic physics.
An objective space and objective time exist.
Space is measurable.
Different perceivable spaces are part of one and the same space.
This space is one and the same throughout time.
Time is measurable.
Time is uniformly directed
The flow of time is uniform within an inertial frame of reference.
Time is an extension in analogy to space, whose parts can be summed.
The unit of time is derived from space, that is, time is measurable by the speed of a spatial process that is again assumed to be uniform in relation to the flow of time.
The imagined past actually existed and led to the present
Mechanical causation is real
Reductionism applied to the sensory images, the holistic phenomenon, appearing to consciousness
etc. the theoretical world of scientific physicalism is objectively real, a clockwork world for clockwork thinkers that forms the basis
at least of corporeal existence.
More diverse:
All creatures originated within this physical world and as a product of mechanical process.
All existing physical structures, in fact, as they are, originated in a natural mechanical process, for example, geological structures through time, radioactive isotopes from parent sources, etc.
Naturalistic "explanations" are epistemologically preferable and take precedence over invocations of intelligence, much less of preternatural or supernatural acts ... because because.
Oh, and finally, a favourite implicit invocation:
God wouldn't do x,y and z, because that is not "rational". Quod erat demonstrandum.
And ones for the theistic evolutionists:
Genesis is an atttempt at explaning the origins of
this world, hence if evolutionism is correct, it is not historical.
Man was first created in
this world.
The Fall is a morality tale, not a cosmic event with physical and metaphysical implications, and it did not bring man into a fundamentally different world to that of Genesis 1 and 2, whose nature is not the work of God.
With respect to these last ones, as I've said before, I am not a dogmatist but a skeptic of naturalistic evolution as historical fact, namely, I think it is in principle impossible to demonstrate the truth of such an "historical science", regardless of merits or demerits, and there are many; I am prepared, however, to accept the possibility of the old age of this world and the Darwinian thesis that a process of bloody evolution brought about the various species in their law-bound physicality.
But I will never accept the proposition of theistic evolutionists that these are the work of God Most High and his Son, the eternal Logos. If an intelligence formed it and by such means, it is a counterfeit, formed from God's original perfect and by fiat ex nihilo material creation, by a power-mad, blood-lusting and ultimately bungling counterfeit deity, no doubt identified in 2 Corinthians 4:4, the Serpent of Eden.
That is not the God I know, not the God I have met in Jesus Christ, not the God of the angels I have seen with my own eyes and conversed with, and if he is the supreme being, if the supreme being is truly responsible for a world in which the Darwinian version of history is the case, then he is not to be worshipped but spat on in the face.
The truth of evolution would not make me an atheist, but that of theistic evolution without doubt an antitheist who would seriously reconsider Lucifer's position as villain in the cosmogony. But theistic evolution is not true.