What are the scientific reasons why humans need morality to know what is good, bad or evil?

Taking evolution and natural selection into account, morality for humans to know what is good, bad or evil is useless. The lion does not feel it is wrong to go down to the watering hole and catch an old or sick wildebeest, or a young springbok and making a meal of it. The lion is not going to feel remorse for killing some springbok’s offspring, that offspring is feeding their cubs. The reason why lions do not routinely kill other lions would also lend the thought that they do not have hatred within the species as man does. If animals do kill member of their own species through accident or some other action do they feel the need to atone for the lost life? If a bunch of seals crushes a baby seal pup by accident, will any mourn?

Is morality hard wired in humans? What is the scientific cause or reason for human morality that other species did not get? Why does man’s morality extend to some species but not to all of them, not even his own species when most other species do not kill each other without cause?