Bacon
Bacon uses the term idols in a negative way. He doesn't mean people worship them but rather that they obstruct a person's ability to correctly perceive the world around them. This is bad word choice and does not convey his meaning very well. To me the Idols of Marketplace would have the most effect on people because we seem to take seriously the things others say. A good piece of our personality and views are shaped by the people we know. It's hard to judge an idols' distortion of the truth so we can only estimate.The Idols of Tribe and Cave are the ones created by inner reflection and those of Marketplace and Theater are made by social interactions. To truly be free of idols you would have to be more open to all ideas no matter where the come from to gain the most true view of life. A hermit would be to consumed with Idols of the Cave and would never have them corrected by other people.
Darwin
Darwin's survival of the fittest means exactly what it says, that the strong will survive and thrive while the those not strong will fail. Natural selection is part of this theory because it is a tool to achieve maximum strength in the species. If there were two different colors of butterflies in the woods one brown and one pink which one would survive? The brown would have the best chance because it blends in better. As a consequence more brown butterflies would reproduce giving you a stronger group as a whole that can survive against predators.Breeding is a direct and more efficient method of creating a stronger species. Scary as it is, humans are on their way to being able to select which genes they want for their child. This would create a super-species with disease resistance, smarts, and strength. Although this is not breeding per say it is very close. This would be an opportunity to create ultimate survival traits without the drawbacks such as long amounts of time and trial and error. Gene manipulation and cloning are very different though. Cloning would be a detriment to survival of the fittest because you would lack certain beneficial aspects than the non-cloned animal has but would never get to acquire.
Human social policy does have an effect on the survival of the fittest theory. If we prop up those who fail we will not be much closer to better genetics. Most of the reason why humans no longer adapt is because, in my opinion, we have what we need. In order to gain the benefit of natural selection you have to have the need to survive, humans already have that. Consider how little we've changed over the last couple thousand years. The only reason we've changed at all is because of a protein and nutrient rich diet.