Now this is pretty cool. Since 2007 the Australopithecus afarensis skeleton AL 288-1, that's "Lucy" to you and me, has been on tour in an exhibit called "Lucy's Legacy - The Hidden Treasures of Ethiopia." I don't know if the exhibit is going to come close enough to me to allow me to visit it, but thanks to the website eLucy, I can look at the skeleton from home.
Hosted by the University of Texas at Austin, the website allows you to compare Lucy's bones with those of a human or a chimpanzee. This is a great resource for anyone who has been aching for a closer look at the fossils than is often afforded in pop-sci books. Even cooler is that all of Lucy's bones have been CT-scanned, digitally preserving the skeleton and giving researchers a good look at her internal osteology. Hopefully these will be fully released soon, but for now here's a YouTube video of the jaw scan. Look carefully as the scan moves back towards the posterior portion of the jaw; you can actually see the roots of Lucy's teeth!
This is really neat stuff, but I do have two minor criticisms of the eLucy site. First, and the more minor of the two, is that the "chimpanzee" skeleton on the "Compare" page is really a scaled-down illustration of a gorilla. I knew something was funny about it, that I had seen it somewhere before, and even though it is not an exact match it very closely resembles an illustration of a gorilla skeleton that appeared in the gorilla-hunter Paul du Chaillu's Adventures in the Great Forest of Equatorial Africa.
More importantly, and perhaps this criticism is more the result of personal annoyance at a persistent evolutionary icon, is that the skeleton of Lucy is placed right between the skeleton of the "chimpanzee" and the human. The image might not be as densely populated as the original "March of Progress" but it gives the illusion that 1) we evolved from chimpanzees, and 2) that Lucy is our direct ancestor and ours alone.
The first notion is absolutely false, as any evolutionary scientist worth their salt will tell you (even if this fact does not hinder half-cocked speculations), and the second is also wrong. Australopithecus afarensis sits near an important junction in the evolution of hominins, representing a form ancestral to both the early members of Homo (like Homo habilis) and other australopithecines (like Australopithecus africanus). Human evolution is a branching bush of diversity, not a single-line march towards perfection, and it's about time we come up with some changes in imagery.
I realize that the creators of the website might not have been prepared with images of the bones of other australopithecines or early Homo, but I have to admit I wince every time I see Australopithecus afarensis plopped down, slump-shouldered, between a human and chimpanzee. Perhaps this qualifies as an example of what Terry Pratchett might call a "lie-to-children" but we should take great care in choosing our evolutionary imagery. I know we like to think that what we say in the text of a book will outweigh fleeting impressions gained from an image, but as Stephen Jay Gould documented in the opening chapter of Wonderful Life, imagery is important. A "simple" illustration can have far greater and longer-lasting impact than pages of well-thought-out prose. Lots of scientists pay lip-service to the branching, bushy pattern of evolution, but I'm sad to say that when it comes to hominins we still want to highlight the "blessed trajectory" of our species and keep our evolutionary siblings in the dark.
UPDATE: Wouldn't you know it? Not long after I wrote this post I became aware of the Rutgers homepage for all the Darwin-related events held on campus this year. Guess what is featured in the upper left hand corner? The freakin' March of Progress! At this rate I am almost tempted to organize my own lecture about evolutionary imagery, but I don't think anyone would come.
[Hat-tip to Afarensis for the news about the video.]
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Hmmm... Now I wish I was more knowledgeable about the use of graphics in conveying knowledge. How does one go about making the nature of evolution and speciation clear?
Maybe a bush graphic? Or a set of overlapping gradients?
wish
I don't know much about primate evolution, but, hopefully "Lucy" will clear up some of the mysteries of our ancestry.
Sean; I think there is a sort of anti-March of Progress art project/website out there, but I don't recall the name and can't seem to find it.
A large part of why I'm so cranky is that many books feature "March of Progress" type images but do not create any other striking images of the branching pattern of human evolution. That fossil hominins are organized in a bush, not a straight line, is rarely made explicit. Comparing a human skeleton to a chimpanzee skeleton to an A. afarensis skeleton is not bad by itself (there are only so many ways to compare skeletons side by side) but it is often THE IMAGE of human evolution with "Lucy" as our ancestor alone.
Maybe graphic exhibits like this will compliment biology textbooks as educational tools, because there's something about having the exhibit right in front of you that has a big emotional impact you wouldn't ordinarily get. Like you, I also cringe when I see the outdated "march of progress" concept being pedaled; it's on the cover of my copy of "Origin Of Species." Ugh!
You sir, are trippin'.
In a very real sense, the 'March of Progress' illustration perfectly depicts any single living human's direct ancestry, it says nothing about all the branches of cousins that died out, and it doesn't have to. People are hardwired to tell a story of how-I-got-here. our lives are completely random, but we tell this pat little tale of development, and school, and people we met, all leading to this moment. So is the path of any organism alive today, there is a perfectly linear set of ancestors back to LUCA. Let the public have their story, nobody doing actual work in biology worries about orthogenesis anymore.