The reason there are tumbleweeds: Part I

As we returned from St. George yesterday on I-15 it was breath-stealing windy and tumbleweeds were occasionally blowing across the freeway. Most were about the size of basketballs. I told my teenage son that you don’t need to worry about avoiding tumbleweeds because they were dry and brittle. I explained they sometimes caused accidents because drivers, not realizing they were not a hazard, might get in a wreck trying to avoid them, either by swerving into another car or flipping the car by trying to avoid them. “Just hit them,” I told him (note: I’m not really worried about my paint job). Fortuitous words. About a half an hour later I spied a monster, six feet in diameter rolling in the wind, at a speed and distance such that a collision looked likely. It was in the section of freeway where the speed limit is 80 mph and I was there. My first reaction was to try and avoid this Volkswagen-sized object, but the words to my son were fresh and newly minted and I did not take my foot off the floorboard or move to take the button off of cruse control. With nary a flinch, I steered steady-on. It was so cool. We hit it square, head on, as it blew across the road. It exploded. I mean it was like a Star Trek vaporization into a kind of confetti-smoke of a zillion pieces of tumbleweed. My wife and son both said, “Wow.” It was spectacular! It was also a calculated descent into rationality. Hitting something that big took a bit of overcoming instinctual programing. But because I had said the words earlier about hitting them, I was ready when the thing became a reality. My own words, “Just hit it.” were still fresh in my mind.

Tumbleweeds are a study in evolutionary adaptation. Those babies are made to roll in the wind. They are light and round as a ball. Back in the days before fences and Hyundai Tuscons those little wonder machines of seed distribution could cover some distance. The evolutionary story behind this little tale of me getting to splash a pulverized tumbleweed across my bow likely began several thousand dozens of ancestors ago as a great-grandmother weed existed that when dry was a little lighter than its competitors and so blew in the wind just a twinge further than its neighbors and since dispersing seeds out a bit spatially was an advantage, it won the reproduction game and passed on its light-dry advantage to its kids (not the proper botanical term—The actual term for weed offspring is cubs or lambykins, I believe). Competition being what it is, soon dryer was out-dispersing less dryer and those with a little genetic advantage in roundness were going a little further than the squarish or triangular ones. Natural selection in action. Soon tumbleweeds were in the world.

Now naively, one might be tempted to say that the reason evolution outfitted tumbleweeds with these attributes was for the purpose of exploding in cool ways for motorists. This is what we would call a teleological explanation. Anything that assigns a direction toward which tumbleweeds were evolutionarily heading, is teleological in nature. My teleological explanation probably sounds a little silly, “tumbleweeds are for smashing with vehicles?” Something seems troubling about that. And in fact as far as evolution is concerned there is no teleology to anything biological. This kind of thinking as fallen completely out of favor within evolutionary biology and no one talks about the where evolution heading anywhere. It is directionless. People often confuse this with randomness and I’ve tried to sort this out a bit (here, here, and here), but what I want to focus on now is unpacking the difference between teleology and purpose. This is because they are often confused. In any kind of Mormon evolutionary embrace we must include the idea that our lives have purpose. Humans are an essential part of Heavenly Father’s Plan. A plan seems to imply teleology. But I want to unpack this a bit because the many of the LDS anti-evolutionary feelings seem to stem from the lack of teleology in evolution getting translated into the idea that evolution implies a purposeless universe or into the idea that humans must be an accidental feature of the universe. This is the temptation of Intelligent Design, as it seems an idea friendly to teleology. Of course, the cost of accepting ID is abandoning science, and that seems like a bad tradeoff. But how do we get Purpose back into our conception of the Universe and still allow evolution to be a teleological-free zone? To explore this we are going to have to make some metaphysical excursions into determinism and indeterminism. These are more like possible world explorations since I’m going to explore suppositions on things ‘ain’t nobody knows.’ But if that’s not blog fodder what is?