Sometimes a negative result in science is just as useful as a positive one. I believe that applies to Intelligent Design as well. Today I’m going to talk about a structure found in birds, which may or may not have been designed. Not being a biologist, I’d like to hear readers’ opinions before I make up my mind.
There are structures found in Nature which were obviously designed. I blogged recently about one recently in my post, The video that proves Intelligent Design: the ATP synthase enzyme. You can watch the 86-second video here.
There are also many structures in Nature which, we can confidently assume, were not designed. In his book, The Edge of Evolution (Free Press, 2007, pp. 78-80), Professor Michael Behe makes a convincing case that the antifreeze proteins found in Antarctic fish can be accounted for in terms of Darwinian evolution. No need to invoke design here.
And then there are the head scratchers that leave us all wondering. One such example is the syrinx. That’s the name for the vocal organ of birds, which enables them to produce sounds, despite the fact that they lack the vocal chords possessed by mammals. The syrinx comes in varying degrees of complexity, and the Australian lyrebird, which possesses an extraordinary ability to mimic sounds, has the most complex syrinx of any bird. How good is it? If you want to find out, I suggest that you click on this Absolutely Amazing BBC link and watch the two videos of the Superb lyrebird (the larger of the two species of lyrebird). One of these videos features the naturalist David Attenborough. And if you click here, you can also listen to Chook, a male lyrebird at Adelaide Zoo, imitating the sound of construction equipment. Here’s what Wikipedia has to say about the lyrebird’s ability for mimicry:
A lyrebird’s call is a rich mixture of its own song and any number of other sounds it has heard. The lyrebird’s syrinx is the most complexly-muscled of the Passerines (songbirds), giving the lyrebird extraordinary ability, unmatched in vocal repertoire and mimicry. Lyrebirds render with great fidelity the individual songs of other birds and the chatter of flocks of birds, and also mimic other animals, human noises, machinery of all kinds, explosions, and musical instruments. The lyrebird is capable of imitating almost any sound – from a mill whistle to a cross-cut saw, and, not uncommonly, sounds as diverse as chainsaws,[2] car engines and car alarms, fire alarms, rifle-shots, camera shutters, dogs barking, crying babies, and even the human voice. Lyrebirds are shy birds and a constant stream of bird calls coming from one place is often the only way of identifying them and their presence. The female lyrebird is also an excellent mimic, but she is not heard as often as the male lyrebird.[3][4][5]
This anecdotal example of the lyrebird’s mimicry in the Wikipedia article is pretty jaw-dropping, too.
So, can Darwinism explain the lyrebird’s syrinx? Over at Why Evolution is True, a short post on the lyrebird put forward a simple explanation for the lyrebird’s extraordinary ability to mimic: sexual selection. Leaving aside the author’s factually incorrect assertion that female lyrebirds don’t mimic, this doesn’t strike me as a terribly good explanation: it tells us why the lyrebird’s syrinx might have evolved, but says nothing about how.
To answer the question properly, it might be more sensible to identify the genes that code for the development of the syrinx, and compare their expression in: (a) the Superb lyrebird; (b) other songbirds (suborder Passeri); (c) suboscine birds, which belong to the suborder Tympani of the order Passeriformes (perching birds). (Suboscine perching birds have a less developed syrinx than that found in songbirds.) One would also need to identify a plausible evolutionary antecedent for the syrinx – i.e. an organ from which it might have developed – and compare the genes coding for the development of this organ with those coding for the development of the syrinx. Having done that, one would need to identify the genetic (and morphological) changes required in order to arrive at the lyrebird’s syrinx, and evaluate the biological viability of hypothetical intermediate forms. Ideally, one would try to recreate these intermediate forms artificially. That would be the kind of research I’d look for, in order to resolve the question of whether the syrinx was designed, and I see no reason in principle why it couldn’t be done. Whether this kind of research has been conducted or not, I have no idea. What I do know that it’s worth doing, if for no other reason than to advance our scientific knowledge and help us to decide whether the syrinx is indeed a product of Intelligent Design. And let the chips fall where they may.
I am a philosopher by training, not a biologist. If readers have any suggestions or comments, or if they would like to propose another way of resolving the question I have raised about the syrinx, they are most welcome to do so.