Betteridge's Law of... oh, whatever. Is the fetal human form a different animal from the adult human form? Different genes are switched on, but this doesn't mea

Betteridge's Law of... oh, whatever. Is the fetal human form a different animal from the adult human form? Different genes are switched on, but this doesn't mean that the baby growing inside of you is some alien that you're nurturing that just happens to become an adult human. Anyway, genetic analysis should make the actual question–if it were a serious scientific question–answerable: are butterflies the result of some prehistoric mating between different species? Is the genetic architecture vastly different between the two sets of genes? Is there evidence of what one or both of these two progenitor species were, and if so, can we identify the direction of gene flow and relative contributions?