h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Scattered through the American Southwest there are ruins of ancient cities built in natural caves, high up on the sides of cliffs. Most were built by the Anasazi, some by the Mogollon, and probably more by other tribes, whom I believe are collectively called Pueblo, but I'm not sure on that.

These tribes left behind more than just monuments of architecture (over fourty rooms at the Gila Cliff Dwellings National Monument are very well preserved, concidering they are 700 years old), they left behind a mystery: All the tribes who built these cliff dwellings eventually, and apparently spontaneously, vanished, probably being absorbed into other cultures but not giving any clues to why they disappeared, why they left these amazing homes.

Whenever one visits such a national monument (two more well known ones are Montezuma's Castle, which has nothing to do with Montezuma and isn't a Castle, and Mesa Verde) the tour guide/ tour book/ what-have-you gives various possible reasons for the flight of these architecturaly gifted tribes. The usual list includes famine, drought, disease, and war. The other night, after visiting the Gila Cliff Dwellings and taking a warm shower I came up with a reason that I've never heard on any list, one that would explain why they moved, AND explain why the Mogollons at the Gila site only occupied their dwellings for 20 years: Population Growth.

I have not studied Anthropology, but I have taken a few courses in Environmental Science, and I know that Pop Growth happens quickly and effects how a society exists. I had wondered how 40-60 people could co-exist in only 40 some odd rooms, when several of those rooms were used for storage and various ceremonial functions. Thinking about it further, I remembered that human history shows that when a culture stops being nomadic and begins agriculture in earnest (they usually go together) as the Mogollons had when they built their dwellings, death rates fall. Usually when death rates fall birth rates take a while to decline to the point where the population is once again stable, and you have a HUGE population growth.

So picture this: you and 39 of your closest friends and relatives arrive in a picturesque canyon with plenty of water and some good fields nearby for growing crops. You decide to settle down and, for protection, build your homes in the side of a cliff where your enemies cannot readily reach you. You have a limited number of caves that are lare enough and accesible enough to support the structures that you build. You stay there for a while, your parents are living longer, and you and your generation produce babies at the same rate as before. Suddenly your population jumps from 40 to 50 or 60 in just a few years. You can't simply build additions onto houses that are in caves halfway up the side of a canyon. You've run out of acceptable caves. What do you do? You move away.

I don't know enough about the lore on this to know whether pop growth is a common reason cited among archeologists when wondering why these tribes disappeared. I do know it's not a reason that is usually listed in tour information. I doubt I'm the first person to theorize this, but if anyone knows whether my theory is common, groundbreaking, or ridiculously wrong, please tell me so. I'd like to know more about this subject.

That's actually a very good theory, Arl. I hadn't thought about it before, but it does make a great deal of sense. Especially in light of the fact that the rooms were all carved at around the same time, rather than some being carved earlier or later than others.

Hmmm... I shall ahve to think about that.

G7

*Stumbles in, somewhat surprised.*

I'm not a journal writer, so I never think to check other people's journals. I've missed some good stuff here!

*Makes mental note to get a reading.*

Your theory makes a lot of sense, Arl. Are the caves the only possible dwelling places? It seems to me that the people would be reluctant to leave a fertile area that they have been farming and would do whatever they could to expand their habitation. Is building out out of the question? And the cliff dwellings - are they natural or carved? If carved, then why wouldn't they just carve some more for the expanding population?

The /dwellings/ are built of clay, similar to adobe buildings common to the pueblo indians of the southwest, but they are /built/ in natural caves. Usually cliff dwelling is done for security (it's hard to sneak up on cliff dwellers from behind. They always have their backs to the wall )

I don't know why they didn't build on the canyon floor, unless they were afraid of floods. I don't know exactly where their fields were, though apparently they did grow corn (20 years worth of discarded corn cobbs can still be seen in one of their storrage rooms). I don't know why they wouldn't have built along their fields, but there isn't any mention of such dwellings in the guidebooks.

Keeping in mind that the time they inhabited the area was just before the end of the last mini-ice age, the threat of flooding was pretty severe. Also, remembering that the area that is now the desert south-west was then fairly fertile and damp. After the ice backed off, it went back to being a desert.

This also could have contributed to the problems they had with a population boom. The fields that used to grow plenty of food for them no longer produced as much...

G7

That's a good point, Gwen, I hadn't thought about the effects of a mini-ice age. It'd be nice to get someone with some genuine anthropological credentials into this discussion. Anyone know a researcher on H2G2 who might fill that description?

according to the stuff I've read on the anasasi, you've just about hit the nail on the head. Over-population, the depletion of natural resources, and the fact that it is believed by archeologists that the cave dwellers were an elite group who survived on mainly donated goods all had a part in their disappearance. Apparently there was a drought, and the priests were unable to collect enough offerings to sustain their communities.
this theory also explains the elaborate road system the anasasi built to the cave dwellings. they traveled there on pilgrimages. At least, that's what the natl geographic artical I read says.

Ah! That's interesting. Of course, you realize that this means that, given limited space even mankind eventually cannot support itself. As much as many people would hate to admit it, Earth is a limited space with limited resources.

*Looks up, startled.

Puts the Big Mac he was eating behind his back.










Note: The Big Mac was used for humourous purposes only - no Big Macs were actually consumed in the creation of this post.

did that come with fries and a coke? haven't had one of those in years. ::rushes out with dollars clutched in hand to correct this oversight::