@neologist,
That's a red herring, although probably unintentional. It was Spencer, not Darwin, who coined the phrase "survival of the fittest." Darwin did use it in a later edition of
Origin, but likely because it has some currency by then. It is a considerably less than accurate metaphor for natural selection, however.
It applies to species, not individuals. Any individual which survives if fit, that's the definition of "fitness" for an individual. The mechanism of natural selection is that those individuals whose traits or behaviors enhance reproductive opportunities, and who reproduce and raise to sexual maturity offspring displaying the same traits or behaviors, and who subsequently reproduce and raise to sexual maturity offspring who then reproduce, etc.--leads to the evolution of a species. Therefore, the metaphor of survival of the fittest can only apply to species, not individuals. That stupidity of the putative Jesus toward the fig tree has no relation to evolution, and it is absurd to claim that it in any way reflects the mechanism of natural selection. It got blasted because Jesus was being a dick, not because any attribute of the tree doomed it.
Species commonly survive after some of the members of that species evolve. Very likely, grizzly bears and polar bears are only separate species because of sexual isolation (one of the criteria for speciation)--contemporary scientists are certain they would be reproductively successful if they interbred. Mammoths and wooly mammoths both survived at tht same time. Einkorn, emmer and teosinte (respectively, two species from which modern wheat derives and the species from which corn/maize derives) all survive today. To allege that cultivars are not products of natural selection is to indulge that silly religious tenet that man is special, and set apart from the rest of the natural world. Man is a part of the natural world, and the cultivation of plants is, therefore, an agent of natural selection. We don't claim that because ants "farm" aphids that they are the product of a special creation, and that therefore, they are removed from the process of natural selection.
You need to understand the mechanism of natural selection before you throw around that "survival of the fittest" metaphor.