Today one of my colleagues gave an excellent lecture on the ecological view of the human self. She was really humming along, connecting the ecological insight to its key influences and themes, when one of her slides brought me up short.
In the middle of discussing the contribution of genetic and evolutionary knowledge to what she was calling "ecological wisdom," she showed a color version of this drawing showing the bone structure of a bat wing, whale flipper, horse leg, and human hand. The label was "Convergent Evolution."
My colleague went on to say that ecology draws from evolution the message that life often solves the same problem in the same way -- that many different life forms have evolved the same solution to the same problem.
Suddenly it all came flooding back to me. I had seen a previous version of this slideshow the last time the course was taught, and this slide was present. At the time I felt a shiver of dread. The label and description were wrong. The bone structures of mammalian forelimbs are an example of homology -- the reconfiguration of a common skeletal formation into several different shapes by lengthening, shortening, and changing the angle of the bones. Although the flipper and the hand, for example, look very different, underneath it's the same number and configuration of bones.
Convergent evolution, what my colleague was describing, would be better illustrated by a slide of a bat wing and a bird wing. Mammals and birds evolved flight separately, and both independently developed the wing structure to achieve it.
When I saw the slide last year, I made a mental note to speak about it to another of my colleagues, one who specializes in scientific scholarship. And I did, later that same day. "We need to let Mutual Colleague know that she's not using that slide correctly," I said, and he agreed.
Obviously we failed. Neither of us ever mentioned it to her, and here was the slide again and the accompanying narration again (it appears twice in the presentation to my increasing distress).
Why didn't we say something? Why have I still not said something, having seen the mistake repeated? Because it's hard to correct a colleague. When you're up at the podium giving a lecture with several other professors in attendance, the pressure to be accurate and insightful is enormous. You feel a gnawing fear that your notes are riddled with errors, that every improvised aside is a potential misstep, that the fact or interpretation you just dredged up from the muck of some lecture you yourself heard years ago was discredited last week with great fanfare, and no one told you.
It's a vulnerable position. And I hesitate to undermine a colleague's authority, even in private. Plus, correcting her feels painfully close to criticizing her. It's an elevation of my knowledge over hers in a field that is far away from my expertise and closer to hers. It's just a very uncomfortable thing to do.
Yet my failure to do it means that the incorrect slide and the incorrect information went out to another 150 students today. Some of them probably knew -- or suspected -- that it wasn't right. Maybe they wrote it off as an honest mistake (though given the repeated explanation, it's hard to see it as anything but incorrect understanding). Maybe they looked at the rest of her presentation with more skepticism given this fundamental error. And maybe the rest of them, the ones who didn't know better, now have a muddled set of terms and images in their heads that I can never eradicate.
Or maybe nobody was paying that close attention and it's no big deal. But I can't help feeling anxiety about it -- both about the error, and about my failure to prevent its repeat dissemination. I'm sure I make lots of errors in my lectures, and I don't want -- but I need -- people who know better to correct me. How to do it without doing damage to already-fragile relationships, though, is beyond me.