Final answer:
Light skin pigmentation evolved as a beneficial mutation for vitamin D production in regions with less sunlight, while dark skin protects against UV radiation in tropical areas. While skin pigmentation changes have been evolutionary responses to environmental conditions, the relationship between skin color and frostbite susceptibility is not clearly established.
Step-by-step explanation:
Light skin pigmentation is indeed a form of mutation that occurred as humans migrated out of Africa into regions where sunlight is less intense and more indirect. Due to reduced ultraviolet radiation in these areas, light skin became of selective advantage as it allowed for the formation of essential vitamin D beneath the skin. The production of vitamin D is critical for bone health and immune functions, providing an evolutionary benefit to individuals with lighter skin in regions far from the equator.
In contrast, dark skin pigmentation was advantageous in tropical regions to protect against excessive vitamin D synthesis and the damaging effects of ultraviolet rays. Adaptations to environmental conditions, including skin pigmentation and temperature-sensitive proteins, show how humans and animals evolve traits that provide survival advantages in their respective climates. Interestingly, depending on these environmental pressures, skin pigmentation changes are sometimes reversible over time.
Regarding frostbite susceptibility, there is less clear evidence linking skin pigmentation to a difference in susceptibility. However, adaptations in human skin, including pigmentation, show how humans have evolved to thrive under different environmental conditions, like cold climates, suggesting a potential link between physical adaptations and resilience to climate-specific ailments including frostbite.