Final answer:
Most scientists attribute the majority of skin aging signs to sun exposure, as UV radiation can damage the skin's collagen and lead to wrinkles and increased risk of skin cancer.
Step-by-step explanation:
A majority of scientists now believe that most signs of skin aging are caused by c. sun exposure. Ultraviolet (UV) radiation from the sun can damage the collagen fibers in the skin. This damage can lead to an acceleration of the skin's aging process, manifesting as wrinkles and loss of skin elasticity. In addition, excessive sun exposure can cause sunburns and increase the risk of skin cancer, including melanoma, especially if the overexposure occurs at a young age.
Although other factors like poor diet, smoking, and chronic illness can contribute to skin aging, they do so in the context of secondary aging. This is opposed to primary aging, which is determined by biological factors. The controllable aspects of secondary aging, such as sun exposure, are significant because modifying our environment and lifestyle can help mitigate their impacts.