From the National Geographic Article:
"Yet scientists say we should be wary of referring to animals when considering what's acceptable in human society. For instance, infanticide, as practiced by lions and many other animals, isn't something people, gay or straight, generally approve of in humans."
Certain chimps practice canabilism -- should we be considering that too? Lots of animals practice polygamy too, does that mean that we should? I doubt it.
Ultimately we have to take a lot of this stuff for a grain of salt. Animals are animals, and humans (while biologically grouped in the same phylum with other animals) are of a completely different sort due to their levels of reasoning and self awareness.