On the way to her exam this morning, the Daughter brought me a poster that she’d plucked from the noticeboard down the corridor [1}. We read it together, & much hilarity ensued.
Evolution "occurs via beneficial mutation." Birds exist. Assuming evolution, birds would evolve wings. The ‘wings’ of first birds are non-functional and thus, are not beneficial. Bird evolution would therefore require the preservation of non-beneficial, non-functional, semi-formed wings! Evolution is an incoherent theory – see the full story at www.drdino.com [2]
I can agree with the author of this tract that birds exist. For the rest – I can only assume that whoever put it up on the noticeboard either hadn’t taken biology or, if they did, had their fingers in their ears & their eyes closed for a lot of the course.
Let’s have a straw man starter: Evolution "occurs via beneficial mutation." Well, no, no it doesn’t. Mutations occur randomly. If a particular mutation happens to convey an advantage to the individual carrying it, such that they are more likely to survive & reproduce, then it’ll probably be passed along to the next generation. Evolution results from natural selection’s actions on individuals that possess a range of mutations, which may be beneficial in some contexts, or harmful, or simply neutral. (Genetic drift is also important, but our writer hasn’t mentioned that.)
Assuming evolution, birds would evolve wings. No, again. Evolution doesn’t look to the future. An observer 80 million years ago would have had no way of knowing that the feathery little reptiles observing him (with lunch in mind) from the bushes were the distant ancestors of modern birds. The fact that today we recognise birds by their feathered bodies and wings does not mean that the evolution of wings was a given, way back then.
The ‘wings’ of first birds are non-functional and thus, are not beneficial. Says who? Feathers definitely evolved well before fully functional aerodynamic wings, as demonstrated by the existence of a range of feathered dinosaurs. Remember that feathers aren’t just involved in flight, but also provide insulation. Their appearance in the fossil record, on manifestly non-flying animals, suggests another function then too. Nor were those dinosaurs’ feathery forelimbs ‘non-functional’; they just weren’t being used for powered flight. (However, fossils like those of the tiny Microraptor do suggest that feathers on the limbs might have conferred some ‘lift’ as the animals ran about, thus making locomotion more energy-efficient – a feature that would be favoured by natural selection.)
I know where the incoherency lies, & it’s not with evolutionary biology.
[1] I did put it back afterwards. With my response 🙂
[2] A Young-Earth Creationist website. Which promotes – among other things – the views of Kent Hovind. Even Answers in Genesis has disagreed with him on occasion!
Grant says:
I’ve no idea how this hypothesis stands with current thinking, but I recall reading that hypothesis was prior to true flight wings were arms that aided climbing trees that gradually developed to an aid for escape by gliding off, rather than jumping off, and then to “true” flight.
This would provide a gradual series of small developments, each advantageous to the animal.
Alison Campbell says:
Depends whether you go for the ‘arboreal’ (trees-down’) or ‘cursorial’ (ground up) hypothesis, I think:-)
Jim Thomerson says:
There was a paper about 15 or more years ago on insect wing evolution. As I recall, insect wings are important in thermoregulation, and the larger they are, up to a point, the more efficient they are. At this point in wing size they are large enough to have aerodynamic functions. So the question, “What good is half a wing?” can be answered for insects.
Alison Campbell says:
I seem to remember that Stephen Jay Gould wrote something about this too; must search it out. (Did wonder about mentioning the insect work, but thought it might get too far off-topic since I was going to stick my response up on the noticeboard along with the original offending article.)