In the Japanese TV series
"Superdimension Fortress: Macross
", a race of highly advanced sentient creatures, who created the giant Zentradi
warrior-races using genetic engineering
This race mysteriously disappeared from the galaxy eons ago, but ancient relics dug up on earth has led to speculation that Protoculture was somehow involved with the development of humanity. The fact that humans, Zentrans and Meltrans are all genetically compatible for reproductive purposes (although there are issues with size differences), is circumstantial evidence
supporting this theory.