I would assert that the very fact that any living organism would take action to end its own life justifies why the action should be taken. Forcing such an organism to survive and possibly procreate is detrimental to the species in question and thus such mal-combinations of genes should be...
easy.. math (in its most simplistic form) is a constant. 1+1 will always equal 2 no matter how you cut it. Since math isn't particular to anyone dimension, it will always be constant.