Why 'should' atheists be moral?

[LostLocke]

It seems as though having empathy can be seen as a disadvantage to people then. If it wasn't for having empathy you would have no problem doing things to benefit your life which would make the lives of others worse. As an individual (not for society as whole) can you think of empathy as a side-affect of evolution which you would be better without.

No empathy is the hallmark of a sociopath. Having empathy on the other hand is not exclusive to humans. There are numerous experiments showing that at least some higher animals like the great apes and dogs probably have it too.

I think even more than just what we consider 'higher' animals have some, if only a small amount, of empathy too.

And empathy is one of the things that got us to where we are today.
As has been mentioned many times, humans are a social species.
Had we lost our empathy and abilities to work together, or never developed them in the first place, along the way, we wouldn't be here having this conversation. What few humans, if any, that would be roaming the earth would likely be a 'primitive' animal version of what we see today.

Any animal that was "equal or superior" to us while we were developing would have had the capability of driving our population into the ground, or even near extinction, simply by the fact that while we, as a species, were beating each other up (figuratively and literally), they were able to cooperate to rob us of our resources, or even turn us into food.

We learned that working together help us forage, gather, and hunt for food more easily, while giving us a better chance to survive becoming something else's dinner.
If we had spent all our time in-fighting and doing anything we wanted to anyone else without concern, our outcome would have been very different.