The recurrent laryngeal nerve in humans begins in the brain then travels down into the the thorax, loops around the aorta, and travels back up the neck where it innervates the larynx. This pathway doesn't makes much sense. A better design would be to innervate the larynx directly without looping around the aorta.
This isn't much of a problem in humans but in giraffes the recurrent laryngeal nerve has to travel several extra meters in order to get to its final destination. Those who advocate that evidence of design is evidence of God prefer to ignore examples such as these.
But can it be explained by evolution? Of course it can. This branch of the vagus nerve is present in fish were it is the fourth vagus nerve innervating one of the posterior gills. You can trace its evolution as the modern blood vessels evolved in the mammal lineage. Mark Ridley describes it, with diagrams, in his textbook Evolution.
You can also see what the region looks like during development on the Critical Biomass blog.
The point is that this is another example of something that makes sense in the light of evolution but otherwise seems quite senseless. The other point is that Intelligent Design Creationism fails to provide any explanation of phenomena such as the path of the recurrent laryngeal nerve.
This is a well-known example of something that looks like "bad design" and that's why it is often used to refute the main message of the Intelligent Design Creationists. Jerry Coyne uses several examples like this in his book Why Evolution Is True.
Have you ever wondered how the creationists respond to these examples of evolution? Here's an example from Darwin's God by Cornelius Hunter: Are Evolutionists Delusional (or just in denial)?.
Coyne inverts the message to say that imperfect designs make sense in evolution. Of course, but so what? So do perfect designs, and everything in between. All these make sense in evolution just as my bad day yesterday makes sense in astrology and warp drive makes sense in science fiction movies. When you can make up whatever just-so stories come to mind, then everything "makes sense."Are you having trouble following the logic of this argument? Let me help you out with the short version ....
The bottom line is that it is precisely from theology and metaphysics that evolution derives its power. Evolution is proclaimed to be a fact by Dobzhansky, Coyne and the evolutionists not on the basis of speculative science. As Elliott Sober has pointed out, evolution's truth status comes from the assumed unlikeliness of design, and all the theology entailed therein. It is, as Sober put it, Darwin's Principle.
Evolutionists like to make factual claims. One fact that is incontrovertible is that evolution is driven by theological claims--that is a matter of public record. Evolution is a religious theory. What is interesting is that the evolutionist denies any such thing. He may as well be denying the nose on his own face. This is truly a fascinating mythology.
Whether evolutionists are liars, delusional or in denial is difficult to say. What is obvious is that evolutionary thought is bankrupt. Religion drives science, and it matters.
Intelligent Design Creationism is a religious theory that fails to explain most of what we observe in biology. But that's OK since evolution is also a religious theory. Nyah, nyah!
[Image Credit: Critical Biomass]
