Veganism

[Angrboda]

You're assuming that it is some property of humans besides being human that forms the moral basis.  What if it isn't?

Being human could be the property that makes it okay to eat animals but not okay to eat humans.

Then we get problems like what counts as being human? If it is having human DNA, for instance, then what if there was a creature very like a human but with different DNA, would it be okay to eat them? Etc. What if you found out that your mother didn't have human DNA, would it then be okay for somebody to eat her? Etc.

This is ruled out as a problem by Liebniz's first law.