Nobody knows exactly when this happened, but probably about 2,000 years ago a clever hunter somewhere in North America figured out that if he had a better way to throw a small spear he would improve his chances of eating dinner that night.
He may have taken the bow he used to spin a wooden shaft and make a fire and discovered he could also use the bow to launch the shaft. Thus came the bow and arrow, a new "weapons delivery system" -- and the drive to build a better version was on.
No doubt he soon learned he could use his new weapon to vanquish his technologically challenged enemies, who were still in the spear-and-dart phase, and quite possibly the world's first arms race began.
No one knows how close that scenario is to the real facts, since experts can't even agree on when the bow and arrow was invented, but anthropologists at the University of Missouri-Columbia think they have pretty well nailed down at least part of the story: Soon after the new weapons system was invented, everybody wanted to build a better one.
"We keep tinkering with something, trying to make it better, and I think that's exactly what folks were doing prehistorically," said R. Lee Lyman, chair of the department of anthropology. Lyman and two Mizzou colleagues, Todd VanPool and Michael J. O'Brien, examined more than 1,000 projectile points at three different locations in North America to see how that technology evolved.
In a paper scheduled for publication in the Journal of Archaeological Science, the researchers say their expectations were fulfilled. Bow and arrow technology spread like wildfire across the continent, and with each hunter trying to improve on the critical arrow point, the poor designs fell away and the arrowhead became pretty much standardized.
For one thing, it got a lot smaller than the hefty projectile points used on the spears that were either thrown or launched with an atlatl, a device used to increase the velocity and range of a spear.
All of this might just seem like common sense, but in fact it is hotly debated among experts. The archaeological record is quite murky. The main evidence comes from the points themselves, since wood used for the bow as well as the arrow does not preserve well. And it's difficult to find a precise date for the points, since they don't carry the "date they were minted," as Lyman put it.
Instead, archaeologists date the points based upon the material in which they were found, which normally includes organic matter that can be dated.
But somewhere along the way, someone had to invent the bow and arrow, and it didn't happen just once. It appeared on this continent long after the first immigrants crossed the Bering Land Bridge with their spears, and long before the first Europeans arrived.
Some archaeologists believe stone arrowheads were being used in Africa more than 20,000 years ago. And the mummy of a man, believed to be 3,300 years old, was found with flint-tipped arrows near the border between Austria and Italy.
So why all this effort to nail down the history of the bow and arrow in North America?
"It's just a little problem we thought might be fun to look at," Lyman said.
The researchers studied hundreds of projectile points at three archaeological sites: Verkamp Shelter in central Missouri, which has been used for the past 6,000 years; Mummy Cave in northwestern Wyoming, used for 9,200 years; and Gatecliff Shelter in central Nevada, used for 5,500 years.
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.