I just got this from googling, it seems less crack pot-y than I imagined: https://phys.org/news/2013-07-chimp-pig-hybrid-humans.html

I'm having trouble finding the links as the recent humanzee hype currently dominates everything. ... Wait, here is the main page where this is discussed in detail with references: http://www.macroevolution.net/human-origins.html

However, it is critical to understand that with hybrids there may be little if any genetic evidence remaining or it may be simply too scrambled to understand. Hybrids from a genetic point of view are complicated and do not necessarily leave a well defined record in their genetics.