Nemyar i sent you a PM

I always go for Engineering first, Exploration second. Often I won't get L2 Farming until just before L3. Immediately L2 Engineering is gained I switch as many as possible to building the dam. If I've got 200-300 food points I'll take the farmer away and put him to work building the dam as well. In the early stages the tribe can live without a farmer for a long time if the kids are out mushroom-hunting. I just have to remember to switch him back to farming if the food stocks start to get dangerously low, or before leaving the game for a while. Once the dam is built I set most villagers on to Research leaving at the most a couple of villagers to continue any current building projects.