I finished a book this week; Your Inner Fish: A Journey into the 3.5-Billion Year History of the Human Body by Neil Shubin. It’s a clearly written scientific text by an anatomist/paleontologist who was part of a team who in 2004 discovered the tiktaalik, a transitional animal from 375 million years ago sharing common characteristics between fish and amphibians; essentially, the until recently theoretical first fish who crawled out of the water, started breathing air and walking around.

That, however, is not what the book is about. The book itself deals with how this animal, as well as pretty much every other animal before or since, has a heck of a lot in common with us, homo sapiens, both anatomically and genetically.

Shubin describes how our basic skeletal structure, particularly in the case of limbs, is common across pretty much all vertebrate animals, and traces that structure back to particular genetic markers. In short, we, and every bird, reptile, frog, or kitten are pretty much ancient fish, deep down. It’s very cool.

If I were to get potentially controversial for a moment, you can see rather definitive proof of evolution; all the structures in our body pretty much stem from something else in less “complex” animals; two of the three little bones in our ear that let us hear so well, for example, correspond to bones that make up part of the jaws of reptiles; our larnyx, which lets us utter complex sounds, derives from the same basic “stuff” that makes up gill structures in fish. It’s all terribly clever; mutations and natural selection led to all the diversity of life on this planet, each creature well-suited to it’s ecological niche.

Notice I say “clever”, and not “intelligent”. The concept of “intelligent design” (which is nothing but re-dressed biblically-literal creationism), is clearly not at work here. While I’m pretty confident in some sort of power greater than us (be it God, physics, or a kid’s science fair project run at a level beyond our comprehension) at work on some level, the designs we’re built from aren’t particularly “intelligent” in the sense of being efficient or elegant. God’s certainly not a skilled engineer, but perhaps She has a bit of MacGyver in Her, able to bodge together clever improvised systems out of whatever’s available to get the job done, but not without long-term issues.

Our bodies are remarkably good at doing the things they do, but they clearly weren’t designed from scratch to do them, and there are plenty of bugs in the system to remind us of where we came from. Hiccups, for example, are a reflex remnant left over from our amphibious ancestors, evident in tadpoles today who inhale water to pass over gills, without drawing it into their lung structures. Men get hernias because the current placement of our gonads require there to be a weakness in the abdominal wall – our more primative anscestors and their contemporaries (sharks and such) keep their balls close to their hearts (literally, that is; metaphorically, many of us do that anyway), and that’s where they start developing embryonically in us. And, finally, a simple look at all the circuitous and meandering routes of the various nerves and muscles within our heads more clearly resembles, and the author describes, the improvised, much-upgraded electrical wiring system installed in a 150 year old apartment building, rather than the efficient conduits in a purpose-designed structure or machine.

And you know, I’m fascinated by this set of circumstances, and there’s nothing at all wrong with them; they’re just part of the continuing cycle that our evolved brains, eyes, and hands allow us to discover and perceive though scientific observation and experimentation. It hasn’t stopped, either: our evolutionary strong points allow us to develop mechanisms (clothing, eyeglasses, surgical procedures) to compensate for our challenges of design, leading to new “mutations” and innovations. We’re merely continuing the modern variant of the same system that caused a strange little fish to heave itself out of the water a few hundred million years ago: because it was advantageous to its species to do so in order to survive.