Thats right, an evolutionary advantage from birth defect does not 100% result in a successful lineage. It can just die and not even pass it on, then later the s

Thats right, an evolutionary advantage from birth defect does not 100% result in a successful lineage. It can just die and not even pass it on, then later the same defect can appear again and again until if results in a lineage. Its an advantage to see better, but it does not guarantee survival just a slightly higher percentage (which is enough to thrive)