AVirah, it is all in principle in the Torah, it does not not mean every Talmid Chocham ,even in times of Chazal, knew it. And why in the world does thinking that Chazal did not know all the science there is to know make one into an apikores?!?! Is it one of the Yesodos Ha’Emunah? Buddy, there is a Gemora in Nidah that when Chachomim needed to know a certain biological/medical fact they had to rely on what the doctors of their time said!!!
