This is a classic anti-evolution argument.  It states that evolution by random mutation is analogous to a 747 being formed by a tornado ripping through a junkyard.  And, since that would be ridiculous, evolution must also be ridiculous.  Indeed, if evolution suggested that monkeys and daffodils spontaneously sprung fully-formed out of a primordial soup of simple chemicals, this would be a great analogy.  However, since evolution doesn’t posit anything remotely like that, this statement is also a classic straw man.

These Things Usually Don’t Scare Crows Either

The straw man logical fallacy is when you bastardize a position to a ridiculous extent, and then argue against that bastardization.  Since this technique simultaneously mocks and refutes something that sounds similar to your opponent’s argument, it can be an effective way to debate.  Of course, that doesn’t make it valid, for the simple reason that you’re not arguing against what the other person is actually saying.

So, regardless of how clever the junkyard 747 argument might sound at first glance, there’s no need to start throwing out all our biology textbooks.  Evolution is nothing like a tornado ripping through a landfill; people making this week’s argument have keyed into the ‘random’ in the term ‘random mutations’ and gone berserk with it.

Let’s briefly go over random mutations and natural selection, to see if they bear any resemblance to a whirlwind of garbage spitting out an airplane.  Take a population of bacteria in a puddle.  The daughter cells of these bacteria will all have random mutations of their progenitors’ genes; a small but significant error rate is a reality of DNA replication in all life.  These mutations will either be detrimental, beneficial, or silent.  The daughter cells with silent mutations will be just as likely to reproduce as their parent cells were, those with detrimental mutations will be less likely, and those with beneficial mutations will be more likely.  There’s natural selection, folks: nature will select for the good mutations and select against the bad mutations.

If you think all that’s in any way analogous to a tornado constructing an airplane, I’ll be a monkey’s uncle.  (As opposed to a monkey’s extremely distant cousin, that is.)  The junkyard 747 is a laughable perversion of evolutionary theory, and using it to attack evolution is an extremely flimsy straw man argument.

So, You Want Trashy Analogies?

Courtesy of Brian Dunning of Skeptoid, here’s an apt junkyard-based analogy for evolution.  This story has really stuck with me since I heard it, probably because I find it really effective to turn this fallacious analogy on its head to actually demonstrate how evolution works.

Imagine a group of welders travelling from junkyard to junkyard, fiddling with pieces of junk at random.  Maybe they weld two things together, or break something, or bend something else; whatever the details, the important thing is that they only make small and random changes.  There are your random mutations.  Now, choose some kind of selection criteria, and pick the improved junk out of your pool of junkyards based on those criteria.  There is your natural selection.  Have your welders make copies of your selected junk to deliver to the unselected junkyards, and repeat the mutation and selection processes.  There’s your next generation of junk.

The overwhelming majority of these mutations will be useless.  However, with millions of junkyards and millions of welders’ trips to these junkyards, you can end up with virtually anything.  After even one generation, you’re almost certain to have the entire assortment of simple machines at your disposal.  From there, you can get pretty much wherever you want.  Select for locomotion, and you’ll be Flintstoning your way to Bedrock within a few generations.  Select for weapons, and you’ll be aping the primates from 2001: A Space Odyssey from the get-go.  (Thank you, I’m here all week.  Remember to tip your waiter or waitress.)  The sky isn’t even the limit; you can select things that help you glide on your way to flight, kind of like birds probably did.

Grasping at Straw Men

Another week, another weak anti-evolution argument.  Luckily, there are only so many of these arguments to go around.  Unluckily, and incredibly frustratingly (holy adverbs, Batman!), no amount of writing like this is going to make these arguments go away.  Some of the highest-profile evolution deniers still regularly truck out these statements, almost as if they expect the scientific community as a whole to smack their foreheads and yell “omg, evolution does violate thermodynamics and it is just as ridiculous as a twister making a plane, lolz, our bad!”

Evolution is one of the most successful theories in science, and it’s going to take more than shoddy pseudoscience and witty rhetoric to disprove it.  That crap, like the debris a tornado leaves in its wake, just isn’t going to fly.  Unless of course you happen to be, shall we say, preaching to the choir.