>>9629572Historically and biologically, animals mate as soon as they mature and are capable of producing healthy offspring, whether you mature at 18, 16 or 14 (12 not so sure tbqh).
However in a society founded upon and bound by civil laws, in order to maintain and enforce said laws you need to set acceptable and clear parameters by which you can measure and judge. This is why the "arbitrary" line of 18 exists - a day before or after really doesn't matter, but it exists as a legal precedent by which cases can be looked at and other laws can be built upon. The rationalization for why the age of consent is what it is varies between country and country, but generally they still all exist.
