Believe it or not, I’m trying to cut down on the Archaeopteryx posts but well, it is a big anniversary and it is such a very cool animal with many interesting and important facets to it’s scientific life that I don’t seem to be able to stop. One thing that really should get a mention is the small role it played it buoying up Darwin’s theory of natural selection.
Perhaps unsurprisingly the initial publication of the Origin lead to rather mixed reviews. While it did have a number of important and influential supporters, it also inevitably came in for some really strong criticism. Darwin has quite rightly noted a number of major problems with his own work and there were certainly some gaps that needed to be filled sooner or later. One of these (which is of course still ludicrously trumpeted by the creationists) was the apparent lack of transitional fossils. If Darwin was right and birds and mammals had come from reptiles, amphibians from fish and so one, then where were all those in-betweens?
The obvious short answer is that 150 years ago the fossil record had only just begun to be explored. We didn’t have many dinosaurs yet (which were nice and big and preserved in big numbers in well explored countries like the US and Belgium) let alone all manner of well, just about everything. Palaeontology as a field was only just getting going and there were very few researchers doing relatively little research and they’d not done much. We now of course have enormously detailed and complete transitional series for the origins of whales and amphibians and vertebrates and all kinds of others. We do of course also know a great deal about the origin of birds, but in addition to its important phylogenetic position, Archaeopteryx very publicly plugged one of those big gaps.
Coming to light a just a couple of years after the publication of the Origin, it was a clear and obvious fillup for Darwin and vindication of his ideas. Here was something that was obviously a bird (it had feathers) but obviously not quite a bird (it had teeth and a long tail and clawed fingers). It was part bird and part reptile - a halfway house. Darwin obviously recognised the fact and it must have been enormously gratifying to see something like this turn up. In a letter to a colleague in 1893 he wrote:
“The fossil Bird with the long tail & fingers to its wings is by far the greatest prodigy of recent times. It is a grand case for me; as no group was so isolated as Birds; & it shows how little we know what lived during former times.”
And he also took a letter from another colleague that same year that clearly referenced this fact as well:
““You were never more missed—at any rate by me—for there has been this grand Darwinian case of the Archaeopteryx for you and me to have a long jaw about”.
Darwin was therefore well aware of just what Archaeopteryx could do for his ideas and as he notes, the birds had seemed an especially disparate group compared to other vertebrates yet here was an obvious transition, or at least possible connection, between birds and reptiles. Perhaps more importantly, this obviously was recognised by his colleagues as well and provided a strong case that the fossil record had much more to say about the theory of evolution and that what it would say might well support Darwin. The timing was really quite perfect then.
Thanks to Rich Tabor and Brian Switek for helping me track down those quotes.