True there will have been some cause and effect initially, but hanging around for the food to run out before setting off on a migration would have meant lean times - I reckon they would have learnt to judge the passing of the seasons so they could set off in good time. Couldn't you regard much of what we do in modern society as cause and effect? eg, if I don't get back to my car in an hour I will get a parking ticket, or if I don't get out of bed now I will miss my train. The lines are very blurred. One of the main factors of an advanced society is people learning to live together and respect each other, and for that we need laws - people need to understand time to follow laws don't you think? In an advanced society law breaking is punished by sentences measured in time - the alternatives, capital and corporal punishment are seen as the domain of the less advanced societies (including some of the US States of course but that's a whole other topic!). I can see there are flaws in that arguement too - the reason I personally don't go and murder someone is nothing to do with the punishment,it's to so with the type of person I am, but broadly if there were no punishments then we could not live in an advanced society. This is deep stuff for a Friday morning,I should be working but this is distracting me nicely!