Thursday, November 17, 2005

Shoes and ships and sealing wax

I just finished reading Jared Diamond's Guns, Germs, and Steel. The book was very good, brilliant at some times, so long as he stayed away from the oceans. The ocean seems to puzzle anthropologists terribly. They tend to see it as either an impassable barrier or a skating rink on which on can cruise where one pleases. Unfortunately, the ocean is neither of these things.

With regards to the impassable barrier, the author tends to view the ocean as impassable until one develops walled boats, or at the very least, double-outrigger canoes. These types of vessels, however, are uniquely vulnerable in a way that other forms of maritime transports, known collectively as rafts, are not. A raft does not sink in a storm. The only way to sink a raft is to batter it apart, and battering apart a raft is much more difficult than battering apart a boat. He does refer to rafts once, in which he describes them as unseaworthy and easily captured by Pizarro. Unfortunately, he is highly incorrect in this assessment. First, the balsa rafts on which the coastal tribes of South America depended where obviously seaworthy (they were sailing on the sea, after all), they were, contrary to his assessment, able to tack into the wind, and where also uniquely suited to the environment in which they operated, since the coast of South America has few natural ports, it as necessary for maritime transport to be able to beach itself, something Pizarro could not do. The ease of capture, furthermore, was accomplished because Pizarro was the first, and the Indians had not yet dealt with Spaniards. In later incidents, Spanish attempts to board the rafts did not go well, since the Indians simply cut the ropes, broke the raft apart, and dumped the Spanish into the water, and then paddled the logs back together, retied them, and went on their way.

With regards to archeological evidence, rafts do not tend to look like anything. A traditional log raft, when it is reaching the end of its useful career, does not tend to be discarded. After all, you have all of that pre-cut firewood just floating there. All one needs to do is roll the logs onto the beach, let them dry, and start your fire. Since rafts don't sink like ships do, maritime archeology wouldn't discover any on the sea floor. And a shipwreck produces logs and bits of rope. As for the other type of raft used, the "reed boat", it outlives its usefulness when the ropes holding the reed bundles together give way, meaning that it falls apart into piles of reeds, which one would expect in a marine environment. Unless somehow depicted in artwork, the use of ocean-going rafts leaves very little evidence.

With regards to the skating rink idea, oceans are dynamic things. The author comments on the logical way to cross the Indian ocean--hugging the coasts--with his puzzlement about the population of Madagascar. Coastal navigation is much more difficult, and dangerous, that trans-oceanic navigation. Out in the middle of the ocean, there's not really anything to run into. No shoals, no rocks, no reefs, and the waves are less severe--there aren't many breakers in the middle of the ocean. And, once one is in the middle of the ocean, one can take advantage of currents. The distance between the New and Old world is not constant. If you follow the 2,000 mile Columbus route from Spain to the Caribbean, in a ship that travels, for example, 6 miles an hour, one actually travels only 1200 miles, since the ocean itself, in the course of your travels, has moved 800 miles towards the Caribbean. Sailing the other way, in a ship going a similar speed, one would actually travel 6000 miles. Why did Spain conquer the New World, rather than vice-versa? The trip was a lot shorter, for one thing. Furthermore, the prevailing winds flow along with the current, so not only would one have to sail five times farther, one would have to sail against the wind, probably tripling the total sailing distance. Thus you have a 1200 mile trip against an 18,000 mile trip. How did the Austronesian population manage to reach Madagascar without leaving their detrius on a thousand coastal landing sites? They sailed with the monsoon winds on the Indian Ocean's primary current. When they sailed back, they waited for the seasonal change in the monsoon, and sailed right back.

In his analysis of Polynesia, Mr. Diamond stretches out a map of the Pacific, and see the obvious route to population--island hopping from Asia, and walking to America. Far from the ocean being an impassable barrier, tundra is much more so. The author posits that it took 40,000 years of adaptation to Siberian conditions to be able to walk across to America. Alternatively, one is fishing on a raft in the Taiwan strait, gets hit by a storm, and sits there, doing nothing, until the current brings you to the islands of the Pacific Northwest a few days later. The difference in technology? Tying some logs together v. thousands of years of experience in artic survival. Once reaching the Pacific Northwest, the population dispersion would follow approximately the same pattern as land-bridge immigrants.

To island hop from Asia, however, one has to sail against the wind (in boats that cannot tack) and against the prevailing current. Alternatively, one could sail from South and Central America, with the wind at one's back, on a powerful current, and be taken directly to Polynesia.
The basic premise of his book was very good, but his application of the hypothesis to ocean travel left much to be desire.


Blogger Noumenon said...

The ocean seems to puzzle anthropologists terribly.

Which other anthropologists are you thinking of?

Diamond does talk about bamboo rafts being used to reach Australia from New Guinea, and makes it sound like they had quite a bit of trouble making passage of only 50 miles at a time (p 42).

Coastal navigation is much more difficult, and dangerous, than trans-oceanic navigation.

This makes sense on its face, but how do you reconcile it with the history of navigation being ships creeping around within 50 miles of shore? I get that mostly from Civilization, but you need astrolabes and stuff to actually "navigate," unless you just wanna blow with the wind.

To island hop from Asia, however, one has to sail against the wind (in boats that cannot tack) and against the prevailing current. Alternatively, one could sail from South and Central America, with the wind at one's back, on a powerful current, and be taken directly to Polynesia.

But I gather from criticism of Thor Heyerdahl that genetic studies may show that island hopping is the way it actually happened, which would back up Diamond's pottery evidence.

3:50 PM  
Blogger Octavo Dia said...

I can't remember offhand, but I remember reading other sources that contradicted that.

The history of navigation being ships creeping around within 50 miles of shore?

The history of fishing, perhaps. I remember an Economist article in the last year or two about the discovery of a Viking map, which had not only all the landmasses, but also all the currents in the North Sea. It's hard to tell where the ships actually sailed (since we tend to find wrecks only in shallow water) and then only the more recent wrecks (unless they're in the Black Sea). When it comes to navigation, it's no more difficult to navigate on the ocean than it is to navigate across featureless deserts and plains. One can still steer by the stars, the sun, the change in direction of the wind, etc.

While not denying that there was some eastward expansion, starting with the same base population, and moving in from the two ends, one would have approximately the same genetic distribution. There is some genetic evidence for the long way round, as the indigenous Taiwanese, Pacific Northwest islanders, and Hawaiians all come from the same base population.

8:00 AM  
Blogger Noumenon said...

That sounds defensible.

12:47 PM  

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