Another Evolutionary Just So Story: How the Human Got His Back Pain

I’ve been thinking about something I read (I think) in Richard Dawkins’ pitiful book The God Delusion, about how humans have problems like lower back pain because we evolved from animals designed to walk on all fours rather than bipedally.

In other words, quadrupeds have fewer problems with their lower back; therefore, the lower back must have originally evolved in quadrupeds, and thus humans evolved from quadrupeds.

Well, by the same token you could look at, say, a horse and reason as follows. Since it walks on all fours, its shoulders bear more weight, and probably undergo more stress and have more problems than (for example) a human’s shoulders. Therefore, by Dawkins’ logic, we should conclude that shoulders must have originally evolved for use in bipeds, because they have fewer problems in bipeds--and therefore horses must have evolved from bipeds.

We don’t even have to know whether horses have more shoulder problems than bipeds like humans to examine the logic of this argument and see that it is false. Once more, “rationalism” is unmasked as simple prejudice.