what is sympathy

I have been quite confused by the fact of both the correctness and ridiculousness of Human Darwinism.
We are all sympathetic. I mean truthfully when you ask your heart. But the flow of the evolution is a condensation of experts and elimination of the dross. Why would we really have to help the poor?
This paradox could be even, quite easily, solved by the possibility of we have a "sympathetic" gene. These kind of solutions are so popular these days. It is very likely, but want to ask myself: "WHY?"
Thinking is such a painful progress; but I keep doing it. I have tried million times to convince myself to either give up or a non-solvable question. But I cannot.
I read Conrad's Heart of Darkness for AP Eng Lit assignment. The vocab is so hard for me and I am even forced to catch up by reading in a, not verily well translated, Chinese version.
Still, the thoughts inside it strikes me even with the existing language barrier.
"......their strong are built on other's weaknesses......"
This did strike me.
Yes. All the time I spent, he spent, she spent, they spent, and we spent are useless. We get stronger but not because of our outreached excellences.
The Giant is giant because others ain't giant.
We all live in one world. Even with different cultures and economically status, we begin to merge. We are not alone and we cannot. Everything is comparative. (This also leads my mind to the shock of first learning Comparative Advantage on the first day of AP Macro Eco.)
Strong is not so strong after all; weak's same.
There is no real weakness in our society. Maybe the person in the highest power, or largest wealth could get a  score of ONE HUNDRED THOUSAND TRILLION. and me or even poorer gets 0.001, the limit of our ratio. even approaching INFINITY, is still the same. B/c he is not a non reachable heights and I has not no meaning to him. We ALL matters.
If somebody gets a cut in the face, he probably will not try to drag his head off.
Once a society reaches an equilibrium of some kind, the best option is to keep it smoothly expanded.