Beware of overzealously reductionistic models of evolution. If fitness were based on counting offspring, there would only ever be bacteria. There would be no c

Beware of overzealously reductionistic models of evolution. If fitness were based on counting offspring, there would only ever be bacteria. There would be no complex organisms and no intelligence. Bacteria leave the largest number of offspring. From that perspective they have the highest fitness. Here's a scenario to get started: Let's say you have someone who has zero children but is a foster parent and contributes to the successful upbringing of dozens of children. Those children then go on, as a result of the actions of that individual, to have far more successful offspring than they would have otherwise. What is this sterile foster parent's genetic fitness? Consider that humans are actually a fairly genetically un-diverse species. We have less genetic diversity than most mammals, owing most likely to a survival bottleneck our species endured at some point in its recent evolutionary past. (There is evidence of this: see "mitochondrial Eve.") As a result, we all have most of our genes in common with other humans. If I have zero children but contribute to the survival of loads and loads of other humans then I am in fact perpetuating the survival of most of my genetic material. The percentage that dies with me is a tiny, tiny percentage. From there research topics like group selection effects, the emergence of cooperation, the evolution of evolvability, etc. This is a gigantic rabbit hole. Ultimately you'll hit the limits of our understanding. We really don't understand yet why there is anything other than boring mats of bubbling goo. Indeed, the first billion years or so of life on Earth appeared to be nothing but that. Then things got interesting, and we're not 100% sure why. It is not as simple as "more kids equals higher fitness." Not at all. If it was we would not exist. "Survival of the fittest," as popularly understood, is such a massive oversimplification that it's basically wrong. "Survival of a subset of the fittest genes over time" is a little better. Racism is rooted in a very pop-science surface level understanding of evolution, which is just as bad as the pop science understanding of quantum physics.