Selfish/Selfless/Altruism are just descriptions for different characteristics that we are perceiving. These are evaluations of some underlying cause.
"We are selfish biologically..."
"He is selfless in his devotion to..."
"This is altruistic behavior..."
But these terms are only somewhat true when evaluating different aspects of our existence.
So it's not that we are selfish, selfless or altruistic but that we display "selfless" sentiment, "altruistic" behavior but the underlying causes of these expressions is our "selfish" gene.
As a group, these are all ethical evaluations, reality is neither selfish or unselfish, but necessity.