(I put this on Facebook first, but I've been told that I'm not getting my point across very well, so, please, any and all feedback is welcomed as always)
When one looks at the human body and marvels at all the things it can do and how each part serves a specialized function and how they all work together, one would think that we were designed, like perhaps a machine or a software program. The problem with that, though, is that if it were true, that we were designed by some sort of, let's say, higher order of being, or a team of them like at a web development firm where I work, that we lacked a QA process. Because, let's face it, we've got bugs.
First of all: allergies. They are wreaking havoc on me now as I write this. Our immune systems overreact to benign particles floating in the air. Pollen, ragweed, they mean us no harm, unlike all the nasty pathogenic viruses and bacteria out there. Yet they can still ruin our day.
A stand up comedian, I can't remember who, once quipped "Why was our waste processing plant put right next to our amusement park?!" Aside from health problems we cause ourselves by poor diet and whatnot, just think of all the default physiological problems that bedevil us, from bad knees to less than perfect eyesight.
Let's look at the eye, for example, pun intended. It's certainly the subject of much debate. To some, it is the pinnacle of achievement in our design. To others, not so much. It's quite handy; where would we be if we couldn't see? When there's more light our iris contracts to let less in, and when there's less light it expands to allow more in. Unlike most animals we can see color. And in a more recent development there are possibly some tetrachromatic women who can see more colors than most people. But the eye has problems. It's inefficient. Images come in upside down and your brain has to flip them right side up. Our rods and cones are near the back of the eye behind fluids and a bunch of tissues. Just think of how much better they'd be at detecting the light if they were closer to the front. And just think of how many people require glasses and/or contacts, like myself. Or if we can afford it we correct our eyes with laser surgery. It's like we're the clients having to fix the bugs ourselves.
However, even with its flaws, the human eye is still pretty amazing. Same with our entire bodies. Just imagine, though, that you're charged with the task of designing a human being. Oh and your deadline is 9 months from now. Your specs document is something like a human physiology textbook. That would seem pretty overwhelming, wouldn't it? That's how most people see the task of making a human. It's much easier to grasp that we were just made by magic alone. But now imagine your project manager, after handing the task to you says: "Hey, don't reinvent the wheel here." And that is a phrase I hear a lot on projects. It means, do what's been done before, but do it differently, or better. In other words, build on what's already been done. Then the project gets much, much easier.
Let's look at the iPhone. I love my iPhone. It's an amazing gadget, isn't it? It's a phone, it's a camera, a music player, a web browser, and an email checker. Trying to grasp the concept of designing and making this thing, or any other amazing piece of technology we have today, from scratch. That, too, seems overwhelming. But consider that every new technology that comes out is just building on previous technological innovations. Look up Moore's Law. Phones already existed. Touch screens already existed. Digital cameras, and even phone cameras, already existed. Digital music players, speakers, headphones, microphones, circuit boards, all were already there. The brilliance of the iPhone's design was the unique way the Apple folks appropriated those technologies. A lot of thought went into usability and user satisfaction. The gyroscope was genius. Apple just built on what was already there, though. Phones, laptop and desktop computers, all are amazing devices, but each iteration was just improving upon what was already there, going all the way back to the first, primitive computers. So it's not as difficult as it might seem to make new gadgets.
So let's go back to the human body. For the sake of scope, just the eye again. Imagining just having the task of designing the eye can seem daunting. But don't worry. Use the eyes that already exist. Look at your cat's eyes, or your dog's. They're pretty similar aren't they? Change the shape, throw in some cones for color detection and you're almost there. And whomever designed their eyes, well that wasn't too difficult, either. They were simply improvements upon even more primitive eyes. Look at the eyes of fish. Then lobsters. Then salamanders. Each successive development just built upon previously established biological technologies. You can take it all the way back to the first eyes on some of the simplest, most now-extinct, life forms. You can do this until you get all the way back to the development of the first monolayer of photoelectric cells that could only detect light. Starting from that, and adding, literally, layer upon layer of improvements, the design of the eyes of highly-developed organisms such as ourselves begins to make sense. It was a bottom-up development, blind to how the future product would look or function. It was a series of experiments. What worked was kept, what didn't wasn't. But the minor mistakes that weren't so detrimental were passed on. Just think of how much better the iPhone would be if everything was reinvented completely with what we know now: the camera, the cell phone, the processor, even the circuit board. But nobody has the time and budget for that.
So, now, again, let's make a human eye. Hey, look, just take the eyes of the Neanderthals and tweak them. Done. See, that was easy! Somebody else did most of the work for you. Let's not worry about the bugs, we don't have time to fix those, the eyes work and that's what's important! Wow, building a human being is a lot like how most of our technological devices and software programs were designed and built. The difference is, ours was built by a natural process (that maybe itself was designed, which is perhaps where the role of an intelligent agent comes in). It's not actually very complicated, just extremely cumulative.
See, the bottom-up development of the human eye, and every other organ in our bodies, wasn't a very intelligent process. But, in its simplicity and elegance, it was a beautiful one.