Err, scientifically? Definitely the brain. We now know a lot about what it does and how it looks and we can even read simple thought processes, but how it evolved and how it is even possible to build such an incredibly complex organ during development is only known in very broad terms.
Comments
kiranminhas commented on :
thaat’s not true though
Vera commented on :
You mean, that the most interesting part of the body is the brain? What is your opinion then?