We Have a Backup Sense of Smell to Protect the Lungs

Just Not That Smart

Our noses have specialized cells that give us a sense of the vapors around us by detecting the presence of chemicals and sending signals to the brain. New research is now explaining how our lungs also have such chemosensors. These sensors send signals not to the brain but to the nearby tissues causing a fast response, such as coughing and wheezing, when we inhale irritating or toxic vapors. Our lungs need this protection since they essentially are open to the external environment. As one evolutionist explained, “it makes sense that we evolved mechanisms to protect ourselves.” But such reasoning violates Occam’s Razor and reveals again how Aristotelianism lives on inside of evolution.

In science we must never multiply entities. That is, gratuitous explanations are not allowed. In this example of odor receptors in the lungs, there is no evidence that they evolved. Indeed, it is highly unlikely. We would have to believe that chance mutations caused odor receptors to be constructed at random locations around the body. And since these are chance mutations, we must also believe that other types of receptors would also be constructed. Furthermore, other types of cells (other than receptors) would be constructed. In short, a vast universe of possibilities would constantly be sampled by evolution. Light sensors, otherwise found in our eye, must have appeared on our big toe at some point in evolutionary history.

Evolution must have been sampling an astronomically large hyper-dimensional design space. Otherwise it never would have luckily constructed these odor receptors in our lungs.

But that is not all.

Having luckily constructed these odor receptors in our lungs (and in the right place in our lungs), there would have been precisely zero benefit. It would have made no difference because there would have been no signaling pathways, to the nearby tissues, for those receptors to excite. And those signaling pathways would have to, in turn, excite the correct type of response. It wouldn’t help much if the response, rather than coughing, would have been to breathe deeply.

With evolution we must believe that not only did it luckily construct the right kinds of receptors in the right place, but it also constructed the right kinds of signals and responses, so the entire system would work. Such an outcome is improbable.

So the evolution of these odor response systems in the lungs is not likely to have occurred. In fact, it is astronomically unlikely. It is not a scientifically motivated idea and it violates Occam’s Razor to say that “it makes sense that we evolved mechanisms to protect ourselves.” The correct scientific conclusion would be: “it makes sense that we have mechanisms to protect ourselves.”

And this leads us to another aspect of Aristotelianism within evolutionary thought.  Of course there is evolution’s incessant reliance on Aristotelianism’s teleological language. But there is also the use of explanations which, themselves, are in need of explaining. Saying that it “makes sense” that the lung’s odor response system evolved explains nothing and raises enormous questions about how that possibly could have evolved.

This is no different than Aristotelianism’s notorious “qualities” that Descartes bemoaned. A hot fire dried out a damp cloth because, Aristotelians explained, fire has the quality of dryness and heat. But these were nothing more than descriptive labels. The qualities did not explain how the fire dried the cloth. As Descartes later complained:

If you find it strange that … I do not use the qualities called “heat,” “cold,” “moistness,” and “dryness,” as do the philosophers, I shall say to you that these qualities appear to me to be themselves in need of explanation.

Likewise, if you find it strange that we do not use the mechanism called “evolution,” as do the philosophers, we shall say to you that this mechanism appears to us to be itself in need of explanation.

Nothing in biology makes sense in the light of evolution.