It is important to remember that, unless accompanied by convincing evidence for selective advantage, any single inheritable trait is more likely to have arisen from genetic drift, not from natural selection! There is, in my opinion, too much focus on conversation about superficial phenotypic traits like “shape of the nose” this and “angle of the eye” that, all the arguments about how one is better than another. Could the asiatic epicanthic fold give advantage against icy winds? Maaaybe… But it doesn’t even have to. What about the asiatic dry earwax gene? You’d struggle to even come up with a story of how dry earwax or wet earwax is actually better under certain conditions, or you could just say “it’s a single nucleotide polymorphism that could have spread by genetic drift” and be done.

Very few human traits have definitely been naturally selected for: light skin in non-sunny climates for better vitamin D production, sickle cell gene for malaria resistance, lactase persistence for animal milk consumption. Even there, the estimated selective advantage is actually much smaller than you’d expect: lactose tolerance confers only something like 1% advantage! There are many more possible neutral mutations than advantageous ones, and each one has a chance to be fixed in the entire population by genetic drift, meaning that any widespread human trait that is less clearly advantageous than lactose tolerance is more likely to be neutral than advantageous at all.

Even mildly disadvantageous mutations can be fixed by genetic drift, especially in humans since we have had many bottlenecks and founder effects. There was an area in Appalachia populated by blue-skinned people due to founder effect. No one is going to try to argue how having blue skin was actually advantageous for them to blend into their environment! There is an area in Dominican Republic with a very high rate of children born intersex, again due to a founder effect mutation. They are not considered exceptional and live normal lives as their culture has adapted to treat them as routine, as a kind of third gender. But they are not some kind of new level of human evolution, an adaptation for an intersectional era!

The only mutations that definitely cannot spread by genetic drift are those that definitely kill you.

My guess is that no to the first, since I have a 1/3 chance of being in the forked path, vs 1/15 of being in the straight path and my lever being connected.

Suppose you live in a kingdom where everyone is as selfish as you, and you’ve seen on TV many situations exactly like this one where people were tied to the tracks - usually one at a time and occasionally 10 at a time. (The villain has been prolific.) You’ve seen them all follow this logic and choose not to flip their switch, yet out of ~1500 people you have seen in peril this way, ~1000 of them have died. If only their logic had convinced them (and you) otherwise, 1000 of them could have selfishly survived! Doesn’t seem very logical to follow a course of action that kills you more often than its opposite.

(If you don’t want to imagine a kingdom where everyone is selfish, you can imagine one where x% are selfish and (100-x)% are altruistic, or some other mixture maybe with y% of people who flip the lever randomly back and forth and z% who cannot even understand the question. The point is that the paradox still exists.)

Edit: I can see now how in a 100% altruistic kingdom, where you are the only selfish one and you know for sure that everyone else will logically altruistically pull the lever, it makes sense for you to not pull the lever. Presumably there is some population x% split (44% selfish/56% altruistic?) where your selfish decision will have to reverse. Weird to think that your estimate of the selfishness of the rest of the population has a relevance on your decision!

Half the fun of trolley problems is adapting them to puzzles for which they are utterly unsuitable: