On missing links
Creationists frequently like to shout about “missing links” in the fossil record. I came up with an analogy today which I think explains exactly why you shouldn’t get trapped in this bad piece of thinking.
If creationists were philosophers rather than dull-witted fools, we’d dignify it with the word ‘paradox’. In fact, it has some similarity in form to Zeno’s paradox.
But here’s the analogy.
Someone says to you: “there are missing links between New York and Los Angeles”.
So you got out a map and found somewhere roughly between the two cities and explained you’ve found the missing link:
“Tulsa, Oklahoma!”
You have now duplicated the problem: you’ve gone from having one missing link to having two: there’s a missing link between Tulsa and New York and another missing link between Tulsa and LA.
So you then suggest Knoxville, Tennessee and Albuquerque, New Mexico.
You’ve now got four missing links.
You can keep going. Flagstaff, Arizona. Amarillo, Texas. Memphis, Tennessee. Lynchburg, Virginia.
Each time you find a missing link, you’ve created more missing links. Eventually, you won’t be able to reach Los Angeles because there’s a missing link between Manhattan and Hoboken and your creationist friend pulls up some ad hoc objection to you saying “the Lincoln Tunnel”. By playing the game of ‘missing link’ finding you already lose. That’s because we have enough links in the chain to know that evolution happens.
Missing links are a curious thing: the more missing links you find, the more you still have to find. In Zeno’s paradox, Achilles must reach an infinite number of points between him and the tortoise, therefore he can never overtake the tortoise. The evidential demands of the creationist are never satisfiable, just as the atlas maker can never satisfy someone who wants to know about all the missing links. Eventually you have to get down to a certain level of “yes, it’s there, deal with it”. You can drive to Los Angeles despite Zeno-style objections.
And once you’ve piled up enough evidence to show that evolution is possible (and I think that has been done), missing link objections become purely theoretical objections. They make for good rhetoric. “There are missing links!” is a pretty nifty soundbite. Sadly, for some people seem to think the set of good arguments is exactly equal to the set of good soundbites.
Evolution works on a smooth progression with hundreds of thousands of intermediaries. Just as on our drive from New York to Los Angeles, we may have stretches at the beginning and end of the trip where there are lots of settlements and geographical features we can point to in order to say “here’s a link between these two cities”, there will be large chunks of the route (like I-40, passing along through Texas, New Mexico, Arizona and eventually through the Mojave Desert) where you are uninterrupted by towns or hamlets for miles and miles. And then suddenly, you get down into San Bernadino and all your missing links are here: streets, cities, blocks, things with names. They are all here. Despite the creationist telling you that these missing links are here, you can sit on a beach in Malibu to relax after your long drive from New York, even if you can’t give a distinct name to each piece of sand you drove past in Arizona or every drop of water you saw in the Mississippi River.
(Postscript: Google Maps tells me the best way is to go via Columbus, Ohio and Indianapolis, then through to Springfield, Missouri. I had mentally planned a more Southern route: Charlottesville, Virginia, then Knoxville, through Arkansas, then onto Tulsa. I used the analogy of driving across the U.S. because one day I’d love to drive a camper van across America for a few months.)