The new Indiana Jones flick prompts an anthropologist to debunk—yet again!—a resilient strain of crank theories:
Over the last 500 years Europeans and Americans have sought nearly any explanation for the complexity of native cultures in the Americas. Possible influences have been sought in a lost tribe from Israel, European wanderers, and even Atlantis. In the twentieth century extremely popular versions of this vein of thinking have included the idea that the Olmec civilization developed under the influence of priest-kings who came from ancient Egypt, and of course, Von Daniken's Chariots of the Gods, in which ancient cultures around the world are given inspiration and innovation by aliens.
One of the pieces of evidence that is most commonly cited in this less than rigorous scholarship is the presence of pyramids all over the world. If a pyramid is broadly defined as a building that is wider at the bottom and tapers to the top, it is hardly a mystery as to why this structure would be common. Any small child with a block set will tell you that it is very difficult to make the top wider than the bottom. Ditto for sandcastles. More compelling than my ad hoc engineering arguments, however, is the steady accretion of knowledge from around the world of local, indigenous culture histories. Thousands of archaeologists, working on thousands of sites, analyzing millions of artifacts have allowed us to see that pyramid building in Egypt, for example, is a process, developed out of long-standing traditions related to tombs. In Mesopotamia, pyramids are temples, with their own long trajectory of development that can be traced in the archaeological record.
In the New World, there is clear evidence in Mesoamerica and South America (which is where Peru is by the way, Indy) of the indigenous development of pyramid building traditions. Similarly, in North America, the largest, pyramid-shaped earthen structures of the Mississippian period do not appear suddenly, with no precedent, rather they are part of a long tradition of earth mound building that stretches over thousands of years into the Archaic period in eastern North America. There is absolutely no reason to revert to theories of alien intervention unless you are predisposed to think of Native Americans as dull, lazy, conservative people who lack the initiative, creativity, cleverness, and cultural complexity to be responsible for the archaeological remains we can empirically document in their homelands.