My latest Mind and Matter column in the Wall
Street Journal is about parabolas, the evolution of throwing and
angry birds:
The spectacular trajectory of the Angry Birds computer game,
from obscure Finnish iPhone app to global ubiquity-there are board
games, maybe even movies in the works-is probably inexplicable. Of
course it's cheap and charming, but such catapulting success must
owe a lot to serendipitous, word-of-mouth luck. Yet, prompted by my
friend Trey Ratcliff, who created the gaming-camera app 100 Cameras
in 1, I've been musing on whether there's an evolutionary aspect to
its allure.
To play Angry Birds, you must use a catapult to lob little birds
at structures in the hope of knocking them down on pigs. It's the
verb "lob" that intrigues me. There is something much more
satisfactory about an object tracing a parabolic ballistic
trajectory through space towards its target than either following a
straight line or propelling itself.
Predicting parabolas is something humans just seem to find
intriguing. How else do you explain golf? Or the awe in which we
hold good quarterbacks in football and good spin bowlers in
cricket? Our bodies are uniquely good at throwing things at
targets. The trajectory must be prefigured in the brain before the
projectile leaves the fingers. Our shoulders rotate, our scapulas
slide, our pelvises pivot, our arms flex and our fingers
extend.
With the exception of the archer fish, which knocks insects off
leaves with well-aimed jets of water, no other animal uses
parabolic trajectories. A chameleon darts out its tongue in a
straight line. A dog likes catching a ball but could not begin to
throw it. No animal has a throwing limb like us. A chimpanzee
chucks rocks and branches when angry but usually underarm and with
the random aim of a human toddler. The closest any bird-angry or
not-comes to throwing is the Egyptian vulture trying to break
ostrich eggs by strewing rocks in their general direction. The
parabolic ballista is ours alone.
Until 10,000 years ago, most or even all human beings relied on
this talent for gathering at least some of their food-by killing it
at a distance. With the arrow, the spear thrower, the blowpipe, the
boomerang, the sling, the harpoon and the thrown rock, we were
killing prey from fish to birds to mammoths. Not to mention each
other.
The biologists Paul Bingham and Joanne Souza have argued that
the ability to deal death at a distance was crucial to the
development of society, because with a well-aimed throw it was now
easy for even weak individuals to punish those who abused their
position. Not for nothing did Damon Runyon call guns
"equalizers.'"
Yet throwing projectiles may be a feature of comparatively
recent human evolution. For our own race of Homo
sapiens, throwing rocks dates back only 80,000 years or so in
Africa. By contrast, the skeletons of Neanderthals-our doomed
cousins who lived in Europe till 30,000 years ago-show a high
frequency of fractures that roughly mirror the kinds of breaks
rodeo riders sustain. This suggests that they were getting close to
their big-game prey, stabbing horses, reindeer, bears and rhinos
with spears, rather than throwing javelins at them.
Moreover, modern baseball pitchers show a characteristic
backward displacement of the shoulder joint-usually only on one
side. So do the skeletons of early modern European
hunter-gatherers, according to Jill Rhodes and Steven Churchill of
Duke University, but not Neanderthals. They apparently had no
"throwing arm."
Imagine how much keener the joy of the throw if the prize was
food after a day of hunger. No wonder we still love to experience
the thrill of a well-launched parabolic projectile-even a cartoon
of an angry bird.
