One of my pet peeves – probably my biggest pet peeve – about depictions of evolution is how everything is always focused on its “pinnacles” (read: us).
I have a lovely t-shirt from BioMed Central, publisher of awesome open-access science journals. It has a nicely designed tree of life on the front, wrapped up in a stylised cell membrane. I think that’s a really neat idea, and graphically, it’s executed in a very attractive way.
I really don’t like the contents of the tree.
Look at the organisms with the little silhouettes. There are 30 figures, 12 of which are vertebrates, 5 of which are mammals. Arthropods, the most species-rich animal phylum by a margin bigger than the rest of the animal kingdom, are dwarfed in comparison. A single clutch of assorted prokaryotes stands in for two of the three great domains of life, and single-celled eukaryotes are absent except for some yeasts. The tree isn’t even fair to vertebrates. Mammals (5 figures) number between 5-6000 known species, birds (1 figure) around 10 000, ray-finned fishes (1 figure) well over 20 000.
Maybe I wouldn’t mind this sort of thing so much if it didn’t reinforce most people’s unconscious (and completely wrong) picture of evolution. But as the wise man said, pictures are worth a thousand words, and this picture screams that everything aside from mammals is the “miscellany” of biodiversity. (I guess they did treat plants pretty fairly. I’ll give them that.)
This is why I was madly happy to find this:
The picture is from UC Berkeley’s Understanding Evolution site, which I already loved to pieces, but spotting this gem made me love it even more. This is how a tree of life should be illustrated. Clear, pretty, colourful, decorated with nice pictures – and completely non-mammal-centric. Since you are an animal and presumably interested in your own kind, you can click to zoom in on animals, then on vertebrates (which doesn’t actually work for me), but first you are confronted with the tininess of our corner of the tree. I especially love how they didn’t pick a vertebrate (let alone a mammal) to represent animals among the photos.
I’m probably being unfair here, comparing a t-shirt design made purely for aesthetic reasons and a diagram fully intended to educate. Still, a tree of life divided this way can be just as pleasing to the eye as a tree of life pretending that mammals are the point of evolution – and it’s not even the case that BMC Biology, which the t-shirt advertises, is a mammal-specific journal. I think it wouldn’t hurt for t-shirt designers to re-examine their default settings every now and then 🙂