> The notion of abiogenesis occurring only once on earth seems improbable considering complex organs like eyes have evolved independently several different time

> The notion of abiogenesis occurring only once on earth seems improbable considering complex organs like eyes have evolved independently several different times. Not quite. Simple life forms probably existed for far longer than DNA. The fact that we see convergent evolution in complex life forms, which emerged very late in the history of life, only suggests that there are recurring patterns in the system that enabled the formation of higher life. It doesn't suggest anything about the origin of cellular life itself, which existed for hundreds of millions of years before eyes or lungs.