> It takes an intervention to stop an embryo from becoming an adult.
Taking intervention isn't as useful a selection criterion as you make it out to be. It also takes intervention to stop teenagers from making babies with each other. And all they need is time. They often don't even need nutrition or safety. That teenagers left to their own devices will make babies is a fundamental and incontrovertible truth. It may as well be considered a force of nature. It's the entire history of all of biology from the very first multi-cellular organism until today. And yet modern society usually succeeds in preventing them from doing it because we recognize the harms caused by it.
> For any other precursor, something fundamental has to change.
This is both arbitrary and covers a lot more than you admit. For a child to become you today it had to change in very fundamental ways, almost exclusively by external social influence. You are not the same as the child. You are dramatically and fundamentally changed. Your ideas are dramatically and fundamentally different. Your feelings are dramatically and fundamentally different. Your behavior is dramatically and fundamentally different.
This notion of fundamental change only holds up if you arbitrarily hold onto one particular kind of change while blithely ignoring all the countless rest.
> For either of the gametes (the immediate precursors), they have to merge with the other gamete.
So? That's not any more fundamental than the fact that external social influences have merged with your frame of mind to change your behaviors, emotions, and views as you've aged. You are as fundamentally changed from the child that became you as the child is from the sperm and egg it came from. You are changing constantly by merging with external influence. Your ideas are as different as ideas can be, your emotions are as different as emotions can be, your behaviors are as different as behaviors can be. You are the culmination of a lot of merging, not alone in a vacuum.
Taking intervention isn't as useful a selection criterion as you make it out to be. It also takes intervention to stop teenagers from making babies with each other. And all they need is time. They often don't even need nutrition or safety. That teenagers left to their own devices will make babies is a fundamental and incontrovertible truth. It may as well be considered a force of nature. It's the entire history of all of biology from the very first multi-cellular organism until today. And yet modern society usually succeeds in preventing them from doing it because we recognize the harms caused by it.
> For any other precursor, something fundamental has to change.
This is both arbitrary and covers a lot more than you admit. For a child to become you today it had to change in very fundamental ways, almost exclusively by external social influence. You are not the same as the child. You are dramatically and fundamentally changed. Your ideas are dramatically and fundamentally different. Your feelings are dramatically and fundamentally different. Your behavior is dramatically and fundamentally different.
This notion of fundamental change only holds up if you arbitrarily hold onto one particular kind of change while blithely ignoring all the countless rest.
> For either of the gametes (the immediate precursors), they have to merge with the other gamete.
So? That's not any more fundamental than the fact that external social influences have merged with your frame of mind to change your behaviors, emotions, and views as you've aged. You are as fundamentally changed from the child that became you as the child is from the sperm and egg it came from. You are changing constantly by merging with external influence. Your ideas are as different as ideas can be, your emotions are as different as emotions can be, your behaviors are as different as behaviors can be. You are the culmination of a lot of merging, not alone in a vacuum.