According to Paul we die because of sin and because the law made clear we always lack in goodness and are sinners by nature. So sins only can occur when there are "laws" ... the punishment for being a sinner is death according to scripture? Problem with that theory is that in order for someone or something to die there needs to be a law and without a law noone would die. So animals who live without a law could never sin and therefore could never die according to theology.
Problem is: that law that paul was referring to was written 600 before christ... long AFTER all the incidents that were written in the tora and/or bible. Backward compatibility you might say :P
So... people who died before could never have died for sins... since there was no law! Sodom? Gemorra? Homesexual deeds and lawlessness was there but there was no written law! How could these people be punished if there was no law to convict them? You see the problems with the sin theory?