i think inbreeding should have affects for it like if you breed your lion with its kid something will pop up after she gave birth saying "luckly no letheal mutations in your pride...but why would you mate with your kid..? she could have a chance of infertle or letheal mutation cubs!" and if a cub having a letheal mutation "something is wrong here, you mated with your kid and what happend? it has a letheal mutation looks like you have more cubs with bad muts or infertle cubs in your paws" so i think inbreeding should have in game affects