“Many times a ‘mother’ in the animal kingdom will ostracize a newborn. It is difficult to say why, but it happens.”
Aren’t those babies who the mother ostracizes often weaker and, therefore, more likely to die? They aren’t worth the energy to keep alive. Instead of trying to feed an offspring that is bound to die, you can provide more nourishment to those that are more likely to live.That’s actually pragmatic in survival situations. Now, us humans who have “higher” reasoning skills and the technology to save our young and who don’t typically live in survival mode choose to not just abandon our weak ones, but decide to kill them ourselves.