Humans have VIT genes, but fish don't have placenta genes.

Can you explain why fish have no VIT genes? Evolution can.

Can you explain why amphibians only have VIT1? Evolution can.

Can you explain why all reptiles, birds, and mammals have VIT1, VIT2, and VIT3? Evolution can.

Can you explain why Platypus still uses one of its VIT Genes and has no placenta genes, has genes for lactation and no genes for nipples? Evolution can.

Can you explain why marsupials only have genes for a primitive placenta, has genes for nipples, and none of its VIT genes are used? Evolution can.

Can you explain why mammals have genes for a complex placenta, genes for nipples, and uses none of its VIT genes? Evolution can.

Can you explain why fish, amphibians, replies and birds have no genes for any type of placenta or nipples? Evolution can.

So you see - evolution is successful for one single reason - it is more effective than sticking your fingers in your ears and screaming NO NO NO NO NO NO NO!