There are lots of news stories today (as well as PZ Myers’ take) about the fabulous new discovery in Spain of Pierolapithecus catalaunicus, a 13-million year old fossil close to the common ancestor of all living great apes.
The early evolution of apes is where some of the most interesting developments are emerging. Until the recent discoveries of fossils of Pierolapithecus catalaunicus and other early species, the fossil record from this period of our history was pretty scanty. These new fossils are starting to shed light on some pretty major questions, such as how our upright stance came to be and how our brains got so big. Meanwhile, new genetic work is raising the curtain on the evolution of cognition in these early apes, which set the stage for our subsequent explosion.
Yet for all the excitement a story like can engenders, some of the coverage has been pretty irritating. Certain hoary misconceptions about science have a way of taking hold in the journalistic world and seem to be impossible to dislodge. One of these is the notion that paleoanthropologists are focused on discovering "the missing link," and that only the missing link can tell us anything of real importance about our origins. Just consider Diedtra Henderson’s article on MSNBC.com. It includes this rather revealing sentence–
"Coaxed by a reporter to say Pierolapithecus catalaunicus represented a ‘missing link,’ co-author Meike Kohler demurred. ‘I don’t like, very much, to use this word because it is a very old concept.’"
That’s right–coaxed. As in, "Come on, professor, just give us a smile and say it’s a missing link. It won’t kill you, right?"
Henderson is hardly alone. A little googling unearths 59 articles that do their best to call Pierolapithecus a missing link, even if it means putting a question mark after it in a headline. Today, Ira Flatow on Science Friday asked his paleoanthropologist guest whether the fossil is a missing link, even while he acknowledged that the scientist might not want to be "boxed in" with that phrase.
Now, if you learned about human origins 50 years ago, you might well have read things by scientists referring to a missing link in our evolution. The great paleoanthropologist Robert Broom even published a book in 1951 called Finding the Missing Link. But this was a time when so few fossils were known from human evolution that many researchers thought that our ancestry was pretty much linear until you got back to our common ancestor with other living apes. But fifty years later, it’s abundantly clear now that human evolution has produced many branches, all but one of which have ended in extinction. Some are close to our own ancestry, others are further away. Paleoanthropologists don’t get excited about a fossil because they think they’ve found the missing link (whatever that is), but because a fossil can show how early a trait such as a big brain evolved, and sometimes can even reveal traits that have evolved independently several times in evolution. That’s what gets them fired up about Pierolapithecus catalaunicus. So why shouldn’t journalists get fired up as well, rather than trotting out old cliches?
It’s not just lazy journalism, I’d argue, but abets some pernicious pseudoarguments made against evolution. Creationists try to cast doubt on the reality of evolution whenever a new fossil of a hominid is discovered. They crow that the latest fossil has a feature not found in living apes or living humans, meaning that it can’t bridge the gap between the two groups. These arguments hardly call human evolution into doubt. The only lesson that should be drawn from them is that the term "missing link" should be retired for good.