These are some intuitions people often have:

You are not required to save a random person, but you are definitely not allowed to kill one
You are not required to create a person, but you are definitely not allowed to kill one
You are not required to create a happy person, but you are definitely not allowed to create a miserable one
You are not required to help a random person who will be in a dire situation otherwise, but you are definitely not allowed to put someone in a dire situation
You are not required to save a person in front of a runaway train, but you are definitely not allowed to push someone in front of a train. By extension, you are not required to save five people in front of a runaway train, and if you have to push someone in front of the train to do it, then you are not allowed.

Here are some more:

You are not strongly required to give me your bread, but you are not allowed to take mine
You are not strongly required to lend me your car, but you are not allowed to unilaterally borrow mine
You are not strongly required to send me money, but you are not allowed to take mine

The former are ethical intuitions. The latter are implications of a basic system of property rights. Yet they seem very similar. The ethical intuitions seem to just be property rights as applied to lives and welfare. Your life is your property. I’m not allowed to take it, but I’m not obliged to give it to you if you don’t by default have it. Your welfare is your property. I’m not allowed to lessen what you have, but I don’t have to give you more of it.

My guess is that these ethical asymmetries—which are confusing, because they defy consequentialism—are part of the mental equipment we have for upholding property rights.

In particular these well-known asymmetries seem to be explained well by property rights:

The act-omission distinction naturally arises where an act would involve taking someone else’s property (broadly construed—e.g. their life, their welfare), while an omission would merely fail to give them additional property (e.g. life that they are not by default going to have, additional welfare).
‘The asymmetry’ between creating happy and miserable people is because to create a miserable person is to give that person something negative, which is to take away what they have, while creating a happy person is giving that person something extra.
Person-affecting views arise because birth gives someone a thing they don’t have, whereas death takes a thing from them.

Further evidence that these intuitive asymmetries are based on upholding property rights: we also have moral-feeling intuitions about more straightforward property rights. Stealing is wrong.

If I am right that we have these asymmetrical ethical intuitions as part of a scheme to uphold property rights, what would that imply?

It might imply something about when we want to uphold them, or consider them part of ethics, beyond their instrumental value. Property rights at least appear to be a system for people with diverse goals to coordinate use of scarce resources—which is to say, to somehow use the resources with low levels of conflict and destruction. They do not appear to be a system for people to achieve specific goals, e.g. whatever is actually good. Unless what is good is exactly the smooth sharing of resources.

I’m not actually sure what to make of that—should we write off some moral intuitions as clearly evolved for not-actually-moral reasons and just reason about the consequentialist value of upholding property rights? If we have the moral intuition, does that make the thing of moral value, regardless of its origins? Is pragmatic rules for social cohesion all that ethics is anyway? Questions for another time perhaps (when we are sorting out meta-ethics anyway).

A more straightforward implication is for how we try to explain these ethical asymmetries. If we have an intuition about an asymmetry which stems from upholding property rights, it would seem to be a mistake to treat it as evidence about an asymmetry in consequences, e.g. in value accruing to a person. For instance, perhaps I feel that I am not obliged to create a life, by having a child. Then—if I suppose that my intuitions are about producing goodness—I might think that creating a life is of neutral value, or is of no value to the created child. When in fact the intuition exists because allocating things to owners is a useful way to avoid social conflict. That intuition is part of a structure that is known to be agnostic about benefits to people from me giving them my stuff. If I’m right that these intuitions come from upholding property rights, this seems like an error that is actually happening.