Isegoria

University of Washington archaeologists have re-created and tested three types of stone-age spear tips:

So Wood traveled to the area around Fairbanks, Alaska, and crafted 30 projectile points, 10 of each kind. She tried to stay as true to the original materials and manufacturing processes as possible, using poplar projectiles, and birch tar as an adhesive to affix the points to the tips of the projectiles. While ancient Alaskans used atlatls (a kind of throwing board), Wood used a maple recurve bow to shoot the arrows for greater control and precision.

For the bone tip, modeled on a 12,000-year-old ivory point from an Alaskan archaeological site, Wood used a multipurpose tool to grind a commercially purchased cow bone.

For the stone tip, she used a hammerstone to strike obsidian into flakes, then shaped them into points modeled on those found at another site in Alaska from 13,000 years ago.

And for the composite microblade tip — modeled microblade technologies seen in Alaska since at least 13,000 years ago and a rare, preserved grooved antler point from a more recent Alaskan site used more than 8,000 years ago — Wood used a saw and sandpaper to grind a caribou antler to a point. She then used the multipurpose tool to gouge out a groove around its perimeter, into which she inserted obsidian microblades.

Wood then tested how well each point could penetrate and damage two different targets: blocks of ballistic gelatin (a clear synthetic gelatin meant to mimic animal muscle tissue) and a fresh reindeer carcass, purchased from a local farm. Wood conducted her trials over seven hours on a December day, with an average outdoor temperature of minus 17 degrees Fahrenheit.

(That outdoor temperature seems like it would affect the target quite a bit.)

In Wood’s field trial, the composite microblade points were more effective than simple stone or bone on smaller prey, showing the greatest versatility and ability to cause incapacitating damage no matter where they struck the animal’s body. But the stone and bone points had their own strengths: Bone points penetrated deeply but created narrower wounds, suggesting their potential for puncturing and stunning larger prey (such as bison or mammoth); the stone points could have cut wider wounds, especially on large prey (moose or bison), resulting in a quicker kill.

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“We have shown how each point has its own performance strengths,” she said. Bone points punctured effectively, flaked stone created a greater incision, and the microblade was best for lacerated wounds. “It has to do with the animal itself; animals react differently to different wounds. And it would have been important to these nomadic hunters to bring the animal down efficiently. They were hunting for food.”

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