The points suggest that the early technocrats initially used spear points on their arrows, which were probably only marginally effective because of their weight. Eventually, they progressed to arrow points with a high thickness-to-length ratio, because that made them more durable. And they quickly discarded the points that did not work well as the new technology sped from one village to another.
The artisans who got it right were, no doubt, the Bill Gateses of their generation. They never had to worry about where the next rabbit was coming from.
"The points that work well are the ones you're going to replicate," Lyman said. "But if you aim it at a rabbit 10 feet away and it misses the rabbit, then you redesign it and build something else and hopefully you will hit the rabbit the next time. If you miss enough, you're going to starve, so you want something that works."
Lyman was himself an archer many years ago, and he knows the evolution of the bow and arrow isn't over.
"When I was a bow hunter 40 years ago, a double-edged broad-head arrow was what you had to have," he said. "Now, they have points that are spring loaded, so the blade springs out, and they can penetrate bone."
But obviously the need to survive isn't driving the technology any more. We have guns now, and we are reminded all too often just how lethal they can be. And we have smart bombs and intercontinental missiles and spy satellites.
And, of course, the bow and arrow, which is even deadlier now than it was a couple thousand years ago.
Lee Dye is a former science writer for the Los Angeles Times. He now lives in Juneau, Alaska.