Most rock paintings and rock carvings or petroglyphs were created by ancient and prehistoric societies. Archaeologists have long used them to gain clues to the way of life of such peoples. Certain rock frescos − such as the renowned Lascaux and Chauvet cave paintings or the petroglyphs of Scandinavia and North America − have already yielded substantial information on our ancestors' daily lives.
However, for other regions of the world like Latin America studies are still fragmentary. In Peru, where many sites have already been located, mystery still cloaks the signification and role of these concentrations of cave paintings and petroglyphs. One of these sites, Toro Muerto, in the South of the country, contains over 4000 carved blocks scattered over several dozen hectares.
Here's the guts of it:
The most ancient sites show a predominance of naturalistic representations of dead or wounded animals. However, a second set dated at 4000 to 5000 years BC eulogizes fertility. This time the images are large, drawn with the abdomen enormously swollen, sometimes containing a foetus. This stylistic development, which seems to coincide with the beginnings of animal husbandry in the high upland regions of Peru, appear to symbolize the emergence of pastoralism and the change in man—animal relationships that came along with this practice.