Evolution's Headache: The Skin Color of Australia and South America

1) The skin color evolution model and the exceptions at high latitudes

Mismatches between environment and skin color reveal limits of natural selection
In many areas, evolutionary theory seems unable to hold up without special adjustments.
The skin color of Aboriginal Australians and South American natives is one example.

Why didn't Aboriginal skin color change for tens of thousands of years?
The evolutionary side says, "Strong UV kept their skin dark." But even in southern Australia and Tasmania, high-latitude, low-UV regions comparable to Britain, Aboriginal people kept very dark skin, at African levels, for tens of thousands of years.
Southern Mediterranean countries such as Greece, Spain, Italy and southern Turkey often see a UV index of 9 to 11+ (extreme) in summer, high enough to burn easily. Do their native populations have very dark skin?

Compared with how quickly pale skin spread in Europe within a few thousand years, the Australian case shows the "environment = skin color" model isn't as strong as expected.
The explanation "they already had dark-skin genes" is close to circular: "they stayed dark because they were already dark."
Like a celebrity photo, it needs too much retouching.

2) Equatorial South America: genes stay, adaptation doesn't

Founder effects and an original blueprint show natural selection is conditional
Why has South American native skin color stayed the same for over 15,000 years?
"There wasn't enough time for it to fully darken" is also a weak explanation.
Fifteen to twenty thousand years directly under the equator in Brazil and the Amazon isn't short by evolutionary standards.
Elsewhere, big changes happened within tens of thousands of years, so why does Native American ancestry here show a strong effect of making skin lighter (according to studies such as the CANDELA project)?
This means the founder effect, the original genetic makeup, works more strongly than environmental adaptation. It exposes the limits of the natural selection model and gives the impression that the main driver of skin color is closer to an original "blueprint."

3) Time-dependent molecular clocks and circular logic

Arbitrary adjustment of short- and long-term rates, and dependence on fossil dates
Has the molecular clock been retouched too?
It's adjusted with a "time-dependent rate," but that amounts to admitting that mutation rates vary greatly over time.
Short-term pedigrees are fast, so long-term calculations are adjusted to be slow.
And the circular dependence on fossil dates remains.

4) Soft tissue in dinosaur fossils, and the gap in preservation mechanisms

The limits of iron as a preservative and the debate over the Fenton reaction
Do the "meat" (soft tissue and proteins) in dinosaur fossils need retouching too?
The mechanism of iron cross-linking and preserving tissue has limited experimental support.
In Mary Schweitzer's research, iron preservation was demonstrated over a period of about two years, and extrapolating that to tens of millions of years leaves a huge gap.
Some researchers point out that iron can actually destroy tissue through the Fenton reaction.
Many remain unconvinced that iron alone explains flexible blood vessels and proteins, and dismissing every repeated discovery as "modern contamination" is yet another retouch.

Conclusion: evolutionary theory held together by patches

Beyond piling up hypotheses to cover exceptions, a fundamental question about the paradigm
I'm not saying evolution is completely wrong. I just feel sorry for how hard it has to work to retouch all the exceptions that keep turning up.