Twins are very low-fidelity copies of each other. They may have been diverging for decades. To use them as counterexamples is dubious at best. (Not disagreeing

Twins are very low-fidelity copies of each other. They may have been diverging for decades. To use them as counterexamples is dubious at best. (Not disagreeing with your point, but your example is not really evidence in favour of it.) EDIT: actually, I think you may have provided weak evidence against your assertion. It's not wildly unusual for a family member to sacrifice themself to save other family members from death.