Darwin's laws can explain it up to a point and only in a general sense. There will be many situations where it would considered ethical (moral) to not act in the benefit of the perpetuation of our species. If I were to jump in front of a car, thereby sacrificng myself to save an 88 year old man with lung cancer, it would not act to the benefit of the perpetuation of my species at all, but it
would be considered ethical in some quarters, even honourable!
Another example. Female infanticide. In pre-medieval (and some modern) societies, when a female was born into a poor family, they would kill her so they would not have to waste scarce resources raising a baby which will be unable to earn like a male would. This is a classic example of adaptation to survive - but if anyone were to do it, it would be considered a most vile and horrendous act!
The issue is better understood if you look at certain normative frameworks. Utilitarianism, whose goal is happiness maximisation (the greatest good for the greatest number) is very much a "survival of the fittest" compatible theory - but it fails in many areas. If we were to take utilitarianism and darwinism to serious levels, completely immoral activities like eugenics or the killing of disabled people/ people with aids etc could easily be justified.
Western society, in general, holds individual rights in high regard. This itself is a testimony to the failure of utilitarianism.
So why is it, that with our highly developed intellect and access to resources, that we don't try to increase the chances of the survival of our species?
I'd say it has to do with a discrepancy between intellect and instinct. That is, our immediate instinct tells us that killing another human being is wrong, whilst our intellect may tell us that killing this one human being could save hundreds more, but in the end, instinct wins because it is our stronger sense. Maybe one day, our powers of reason will develop so much, and our basic animal instincts become so dormant, that we bring eugenics et al back.
Hope I'm not alive to see that!
