from the could've-been-circus-folk dept.
sciencehabit writes "Among the prolific paintings and other art in the 8 kilometer-long Rouffignac cave system in southwestern France are a number of unusual markings known as finger flutings, which are made by people dragging their hands through the soft silt that lines the cave's walls. By analyzing the finger flutings of modern humans, researchers discovered that the ratio of the distance between the three middle fingers indicate that many of the cave artists were very young children, one as young as 2 or 3 years old. The researchers were also able to tell the children's genders from the shape of the fingers."
I've never been canoeing before, but I imagine there must be just a few
simple heuristics you have to remember...
Yes, don't fall out, and don't hit rocks.