Some resources are not renewable - such as mineral deposits, petrochemicals and the like. Whether you use them quickly or whether you use them slowly, they don't come back. For this very reason it is hard to define overuse, since any use at all will have the same effect - depletion of the resource.
Adj. 1. altruistic-showing unselfish concern for the welfare of others. selfless. unselfish-disregarding your own advantages and welfare over those of others.
Altruistic behaviour is therefore the opposite of egoistic behaviour. It involves intention to help others when used of human behaviour, but the fact that some animal behaviour is judged to be altruistic indicates that there are two possible bases to a definition: intentionality, and behavioural effects.