Laelaps

It's strange how we pay lip service to great popular books about evolution yet often forget the lessons between the pages. Such is the case with Stephen Jay Gould's Wonderful Life (1989), a book that investigates the specific case of the enigmatic Cambrian fauna to explain contingency in evolution. Those expecting to jump right in to a discussion of Anomalocaris and Opabinia might be surprised to be confronted with political cartoons and advertisements spoofing the all-too-familiar "March of Progress" first introduced to us in the book Early Man by F. Clark Howell (although this image is in turn borrowing from earlier visuals based upon the idea of orthogenesis and other now-discarded notions). While it has been understood for quite some time that human evolution did not proceed in a straight line (and the text accompanying the image in Howell's book notes this reality), the image is far more powerful than any textual explanations that accompany it. Refuting the erroneous notion of teleological or orthogenic change the March represents, Gould writes;

Life is a copiously branching bush, continually pruned by the grim reaper of extinction, not a ladder of predictable progress. Most people may know this as a phrase to be uttered, but not as a concept brought into the deep interior of understanding. Hence we continually make errors inspired by unconscious allegiance to the ladder of progress, even when we explicitly deny such a superannuated view of life.

Indeed, as much as it pains me, the March appears to continue, the step-by-step sequence of evolution (and it's fallacious pop-culture cousin "devolution") being a favorite of satirists, advertisers, and political cartoonists (see here, here, here, here, here, here, here, here, and here), even making a "cameo" during The Simpson's famous couch gag that opens each show (compare it with the animation from the intro to a Richard Dawkins special below it);

Carl Sagan's similar overview of evolution from the Cosmos series does a bit better in that it is at least suggestive of a branching process, but it still does not fully drive home the diversity of life as it trails our own lineage primarily to the exclusion of others.

If nothing else, these examples should make it apparent that the "March of Progress" is firmly entrenched as a symbol of evolution in our culture, even though it has been understood to be woefully deficient for some time. This is why it was so maddening to click on the "Fossil Evidence" link on the "Judgment Day" website and find that it is still being trotted out as an example of evolutionary change. For each of the five examples, three transitional fossil specimens are reconstructed as being indicative of the evolution of a particular lineage, the famous examples of tetrapods, mammals, birds, whales, and humans being offered. As Don Prothero noted in his recent book Evolution (reviewed here), however, transitions between uncharismatic lineages are even more well-documented, and I would hope that those who wish to invoke transitional forms to teach people about evolution will start picking trilobites, ammonites, radiolarians, bivalves, and foraminifera. Still, I could deal with the choices made if they were illustrated in a more responsible fashion; reconstructing only three representatives of a line leaves out a LOT of important evolution, the connect-the-dots sort of arrangement leading the viewer to believe that one form directly evolved into another.

The text accompanying each section is a bit better in describing the evolution of each respective lineage, but as we saw with Early Man, the visual is far more important the the text that goes along with it and has more staying power in the memory of the audience. A much more interesting and responsible choice would be to construct an interactive phylogenetic tree, at least making some attempt to convey that evolution is a branching bush full of diversity and subject to contingency, and while this section of the website is a supplement to the main purpose of the resource, I am disappointed by the lack of effort put in to a section that it supposed to show positive evidence of evolutionary change. If this were not enough, I find that the 1-2-3 progressive human evolution section still suffers from our own bias as to what makes our species great. In the reconstruction, Dryopithecus is on all fours, Australopithecus afarensis is stooped over, and Homo erectus is (as the name suggests) fully erect. Indeed, it seems that these representations were cribbed from the "March of Progress" (or at least the representations in the March were not questioned), and I see no reason to recreate "Lucy" as slightly slumped over. Many extant non-human primates are able to achieve a bipdeal stance, and I see no reason to think that we had to go through a stage of being stooped over forward before gradually rising to our full height (likely a visual proxy for our increase of brain size and rising to our "intellectual" height as well).

I do not wish to dissuade anyone from watching the "Judgment Day" program; it appears like it is going to be excellent and I cannot wait until it starts streaming online so that I can see it as well (unfortunately I lack a television with reception). Still, the somewhat shoddy construction of the "Fossil Evidence" section of the website shows us that a major part of the problem with evolution education is that many current methods of trying to convince people evolution is accurate are woefully inadequate, the straight-line progression of one body form to another long being recognized as only a way to trace a lineage to the exclusion of others and not truly representative of how evolution proceeds. It is simply not enough to keep creationism (whether in the form of intelligent design, Young Earth Creationism, or some other variant) out of schools; we must start accurately and effectively teaching what evolution is and how it has produced the dizzying diversity of life that existed through the fullness of geologic time. There is no excuse to ignore the reality that we are finally approaching answers to the "great" questions of from whence our species has originated, much less to remain blind to the fact that we are but one in an evolutionary cast of innumerable proportions that is still changing. If we fail to convey these facts, becoming (as G.G. Simpson once termed it) "intellectual eunuchs," then we will continue rear-guard actions while the vast majority of students idly pass through our public education systems, never fully realizing what they have in common with the gorillas they see at the zoo.