Defective Design—Part 2

The human body's most troublesome defect is the “design” of our spine. We humans have evolved from ancient primates that moved around on all four legs, with the spine in a horizontal position. The spine evolved to protect the body's organs and support their weight—being slung below and suspended from the backbone. All four-footed animals today still demonstrate the efficacy of that horizontal spine. It works very well.

A few million years ago our hominid ancestors began to stand upright on two legs. It gave them a few advantages over their horizontal cousins—such as to be able to spot predators farther away and carry items in their forearms. So they prevailed and their horizontal cousins disappeared. We have remained upright ever since. Although we were successful, that horizontally-evolved spine didn't do so well in a vertical position. All the weight of our internal organs, as well as our upper spine, now burdens the lower vertebrae and causes perennial backaches. It's a rather defective structure—but there's no going back for a redesign.

As my second example, two tubes run parallel down the throat of most all animals. One—the trachea or windpipe—funnels air to and from the lungs. The second tube—the esophagus—transports food into the stomach. The esophagus for horizontal, four-footed critters lies below the trachea. Thus food—being heavier than air—naturally drops down from the mouth to the esophagus and wends its way to the tummy. 

Here is yet another problem brought about by our decision to stand erect. In our vertical orientation, we must be very careful to control our glottis (the entryway to our trachea and lungs), so that we don't inhale our food into the lungs. Furthermore, the subsequent development of our voice mechanism added to the complexity and confounded the problem. As a result, we are very prone to choking, and sometimes require someone to perform a Heimlich maneuver on us, lest we choke to death.

I will stop with these two defects at this point, but there are several other shortcomings of the human physiology that demonstrate faulty design—such as goose bumps, hiccups, and an overactive amygdala.  Once they performed useful functions that today are either not needed or are problematic. (For example, we need the amygdala for some functions, but the hyper fear that it causes often gets us into trouble.) The human body—like that of all critters and plants—is a marvel, but it ain't perfect. Any competent biologist could do a better job, with today’s knowledge.