The claim states that human evolution failed to develop complete biological protection against solar ultraviolet radiation. The retrieved literature clearly supports this: papers establish that UV radiation causes DNA damage, degrades skin barrier function, and induces photoaging and cancer (Papers [2], [7], [8], [11]), while human adaptations like pigmentation represent a compromise forced by the competing evolutionary requirement to synthesize vitamin D rather than a complete shield (Papers [3], [10]). Therefore, the evidence strongly supports the claim.