Progress

 The point I was trying to make was that, while hunter-gatherers may have enjoyed more personal freedom than farmers, their lives were not as secure.  Their food supply was more precarious and, because of their nomadic lifestyle, their homes were flimsy affairs that barely kept out the wind and the cold.  If they were lucky enough to find a cave, that only lasted as long as the food and firewood in the vicinity, and then it was off to find another cave, living in temporary shelters in the interim.  As economic conditions improved, population density increased, necessitating more technical innovations to keep everybody safe and well fed.  It also required more social organization to manage the inevitable conflicts that arose.  As these settlements became more prosperous, they presented tempting targets to neighboring groups who weren't so well off.  This inspired more advances in both technology and organization, which fostered more population growth, and so it goes.

There area number of reason why bread dough might not rise properly.  One is the ambient temperature, 70-80 is about right.  Another might be that there is not enough processed flour in the mix.  Whole grain and rye flours do not rise well with yeast, so you need to blend them with regular white flour, at least half.  I used to mix about 3/4 white flour with 1/4 rye or whole wheat flour.  When you start kneading, your dough will seem to be too dry.  Knead it some more and it will get damp and sticky.  When it starts to get dry again but is still pliable enough to form into loaves, you're done.