There is a significant drop in the age of having first child after the Flood. Shem begot Arpachshad already two years after the Flood, when he was 100. Arpachshad begot his first child when only 35. And so forth. Is this drop related to the commandment that Hashem gave to Noach, to procreate and fill the Earth? If so, this commandment was given much earlier to Adam, and it did not lead to the same effect. Any references to some commentary? I did not find any mefaresh that would relate to this.