I think you are misunderstanding the concept of "survival of the fittest" This doesn't mean that those who don't have a particular advantage in an environment are done away with or removed from the population. It just means that those with a certain advantage are more likely to live longer, are more likely to reproduce, more likely to reproduce in greater numbers and more likely to pass on that advantage to their offspring.
Remember in Human beings it is not just about passing one a genetic advantage we have to spend years caring for and raising and culturally teaching our offspring. Fitness is not just in the individual but in the community as well so your 'love thy neighbor' culture is actually an example of survival of the fittest.
As an interesting side note. I just watched a report of frogs in the Chernobyl exclusion zone where frogs have largely stopped being green and are now pitch black. They changed color because of the concentration of melanin in their skin. Melanin protects against radiation so in that environment those frogs with a higher concentration of melanin had an advantages and passed that advantage on to offspring and after dozens of generation those frogs are better suited to survive at least in that environment.
Thank you for taking time to reply. We mostly agree.
”Survival of the fittest” is a crude shorthand for the longer definition of Natural Selection. In a given population of some species, those individuals least fit for their environment will be less likely to survive to adulthood and thrive. Thus the phrase crudely refers to individual survivability as well as an ability to engender the next generation.
Your Chernobyl example seems to illustrate the point. Green frogs have (largely) been less likely to survive the radiation environment long enough to engender the next generation, unless it happens that green frogs survive just fine but their eggs/sperm are largely sterile. Perhaps you could clarify.
Your point about human communities is unclear. With a few exceptions, all individuals will be able(in principle) to survive, thrive, and engender the next generation in a culture in which individuals embrace a personal responsibility for sharing & caring, to be gentle & peaceful, and believe in lifetime, monogamous marriages between men and women. In other words, a Love Thy Neighbor community rejects Natural Selection to the best of its ability.
Does that mean the community will be more likely to survive from generation to generation? That depends on its ability to adapt to its environment, which might include powerful predatory neighbors.
Yet it is always God’s providence that will prevail.
Peace and blessings.