If humans can modify a genome in a way that is not detectable later, why would gods require supernatural qualities to do so?
One must be careful here and conscientiously distinguish between a gene and a genome. Still, the presence of a frost-resistant gene
that humans have taken from a fish and engineered into a tomato’s genome
would cause more than a little consternation among scientists who knew nothing of our tinkering and who found the gene in related fish (sub)species and yet only in one variety of tomato. As a side note, just such genetic engineering has in fact been done
. (ETA: And more