I think that Chesterton's fence is a useful guide when it comes to some incomprehensible systems, including our own biochemistry and physiology. Once upon a ti

I think that Chesterton's fence is a useful guide when it comes to some incomprehensible systems, including our own biochemistry and physiology. Once upon a time it was thought that some organs are useless (thymus in older age, appendix pretty much always). This has been revised. Nature often introduced hard-to-understand systems in order to cope with something we don't even realize is a problem.