The Role of Environment and Adaptation in Eye Color Variation
Eye color variation is influenced not only by genetic factors but also by environmental factors and adaptation. The amount of melanin in the iris determines eye color, and blue-eyed individuals have less melanin than those with brown eyes.
This difference in melanin levels can be attributed to adaptation to different environments. In regions with less sunlight, such as Northern Europe, having less melanin in the iris allows for better absorption of vitamin D from sunlight, which is crucial for bone health. Therefore, blue eyes may have provided an evolutionary advantage in such environments. However, it is important to note that eye color is a complex trait influenced by multiple genes, and the exact role of environmental factors in eye color variation is still being studied.