He's probably referring to the "RNA world" hypothesis, where RNA arose before DNA. DNA is more stable and a better storage molecule for genetic information. This is relatively well-supported by molecular evidence although we can't go back billions of years and check directly.
>but wasn’t DNA present from the origins of life?
He's probably referring to the "RNA world" hypothesis, where RNA arose before DNA. DNA is more stable and a better storage molecule for genetic information. This is relatively well-supported by molecular evidence although we can't go back billions of years and check directly.