science-and-religion, existence-of-godLooking at the mere complexity of the human eye itself I can’t help but look at that and say that there’s an intelligent creator out there. Can you help me understand an Athiest’s perspective on the complexity of the human body and how they can look at the complexity involved and still believe there’s no creator? The idea that humans can just think “I wish I had another arm” enough in their lives and they eventually adapt having another arm doesn’t make sense to me.
Your question betrays several fallacies that are common in people who are skeptical of evolution as a theory. This is fairly common because of the intentional misinformation disseminated by the ‘intelligent design’ religious folks.
The evolution of the mammalian eye is fascinating, and the story of its evolution is illustrative of the manner in which other complex structures may have evolved.
Here’s a quote from pbs.org in their evolution library http://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html
Here’s how some scientists think some eyes may have evolved: The simple light-sensitive spot on the skin of some ancestral creature gave it some tiny survival advantage, perhaps allowing it to evade a predator. Random changes then created a depression in the light-sensitive patch, a deepening pit that made “vision” a little sharper. At the same time, the pit’s opening gradually narrowed, so light entered through a small aperture, like a pinhole camera.
Every change had to confer a survival advantage, no matter how slight. Eventually, the light-sensitive spot evolved into a retina, the layer of cells and pigment at the back of the human eye. Over time a lens formed at the front of the eye. It could have arisen as a double-layered transparent tissue containing increasing amounts of liquid that gave it the convex curvature of the human eye.
In fact, eyes corresponding to every stage in this sequence have been found in existing living species. The existence of this range of less complex light-sensitive structures supports scientists’ hypotheses about how complex eyes like ours could evolve. The first animals with anything resembling an eye lived about 550 million years ago. And, according to one scientist’s calculations, only 364,000 years would have been needed for a camera-like eye to evolve from a light-sensitive patch.
What’s important to understand about the process is that it is gradual across many generations, and very, very many dead ends that don’t produce a competitive advantage for the evolving organisms.
Other good links are referenced off of wikipedia. http://en.wikipedia.org/wiki/Evolution_of_the_eye
Have you heard the term “The invisible hand of the market” to describe capitalism? That’s the notion that given a level playing field, prices will match demand and companies that are good at competition will prosper.
There IS an invisible ‘force’ at work in guiding evolution! However, it’s not the intangible and dubious idea of a creator, it’s the very real and very visible competition among animals and plants to survive. If a mutation occurs, it is very likely to be a bad mutation leading to the death of the organism or to its inability to procreate or compete for resources as well as another, non-mutated member of the same species. However, from time to time slight genetic variation gives rise to a mutation that confers some small advantage to competition and survival. That organism is far more likely to survive, prosper, and thus pass along those genes. Over time that trait can become dominant. Aggregated over time, that’s evolution at work.
I don’t see any reason to think that “I don’t understand how stuff works, therefore there must be a god / gods”. Complexity of human body is very well researched area and we understand already very well where the complexity comes from. That is not to say that our understanding of human body (or any other matter) is complete. There are a lot of things we don’t understand but instead of being happy with the answer “god did it” we try to figure things out using scientific method. Many things that once were mysteries have now been solved with very high confidence level. For example tides, planetary motion, etc. The fact that we don’t know an answer doesn’t mean that there isn’t one (or many).
I don’t think anyone claims that evolving another limb would happen as the result of wishful thinking – that isn’t how evolution works. Your misunderstanding of what evolutionary theory actually proposes may be the source of your confusion.
Since you bring up the eye, you might find it fascinating to know that while the human eye is indeed wonderfully complex, it’s also fairly inefficient. We have only 3 types of color-sensitive cells (cones), where some animals have 4, and thus can see much more breadth of color. Our eye’s lens flips the image of what we see, and our brain has to correct for this perceptually – there’s no design advantage to that, it would be much more elegant if we didn’t have to do that correction.
And that’s just for starters. What we see in the complexity of the human body, when we really look closely, is much more evidence for organs that arose through a series of small changes than for anything that was designed wholesale by an intelligent being. If God really did hand-create everything, then he’s a terrible engineer.
Atheists explain the complexity of the human body by evolution. That is, we believe that life started as a unicellular and grew in complexity through mutations and natural selection.
But you already knew that part.
What you cannot understand, however, is why we find it a more satisfactory explanation than a divine creator. In fact, you said:
The idea that humans can just think "I wish I had another arm" enough in their lives and they eventually adapt having another arm doesn't make sense to me.
The problem, here, is that you don't understand how evolution works. The mechanism you describe above is not evolution. If you believe that evolution claims that humans t grow limbs out of nowhere by simply wishing they had more limbs, you are wrong.
Evolution is far more reasonable and simpler than that.
Evolution rests on three claims:
There is no "limbs growing after birth." A child can be born with an extra arm - and that has happened before - but if he isn't born with it, it won't grow because he wishes he had an extra arm.
In other words, your understanding of evolution is wrong and, if you really want the answer your question, you will have to read more about evolution until you understand it better. Explaining everything to you here would be a huge undertaking and we wouldn't explain it as well as a evolutionary biologist would.
Now, as to why we find evolution a better explanation than a divine creator? That's a completely different question which, fortunately, has been answered on this site before.
Let’s use your logic. If you claim that an eye is complex enough and thus should must have been created by God, then God should be more complex to create something complex.
Using your logic, we don’t answer the question, because there’s no end creator, therefore it’s fallacy.
The only answer is Evolution, progressive complication of body, variety of life forms etc.
You’d want to understand evolution, and there’s a couple of nice recources on it:
I’m sure you’ll enjoy both.
The logical fallacy that you’re using is the “Argument from Ignorance” (ad ignorantiam): basically, you’re saying, “I can’t explain how this came to be, therefore God.” Just because something can’t be explained, doesn’t mean that any explanation is equally valid.
Very commonly used by Creationists (see the magical “irreducible flagellum”) . Ironically, it’s also very commonly used by anti-theists (absence of evidence is actually not evidence of absence…It’s just absence of evidence).
Many other posters have addressed the mechanisms that drive Evolution so I’ll leave that issue aside. Instead, let me address the observation cited by the original poster:
“Looking at the mere complexity of the human eye itself I can’t help but look at that and say that there’s an intelligent creator out there.”
I would encourage you to look a little closer at this design. The human body is actually fantastically bad in many ways. Our appendix serves no function but can kill you if you develop appendicitis. Our eyes are quite inferior when compared to those of other species. Our abdominal muscles lend themselves to hernias. If you’re male and you live long enough, you’re pretty much guaranteed prostate problems. Then there are simple things such as the fact that males expel waste through the same passage as they produce reproductive material. These things don’t strike me as very intelligent design choices.
So, in short, if you look at the human body and consider it proof of an intelligent designer, then you probably haven’t studied human anatomy all that closely. If you concede that the design is riddled with flaws but still too complex to ‘just happen’, I encourage you to read the other posts that have addressed the concepts of natural selection.
The idea that humans can just think "I wish I had another arm" enough in their lives and they eventually adapt having another arm doesn't make sense to me.
The reason it doesn’t make sense to you is because it’s wrong. Worse than wrong. Not even wrong. That’s not how evolution works. Whoever told you that had asolutely no idea what they were talking about.
Yes, the human eye is complex, but no more so than most any other organ in the body. It’s also sub-optimal in a number of respects.
There are any number of potential explanations how vertebrate eyes (and other types of eyes) formed, none of which require anything more than time and refinement in subsequent generations.
Michael Dowd ties together the idea of something being behind creation and the sometimes difficult to grasp facts of 98% of the species that have existed are now extinct. Unfortunately we have all inherited a huge amount of speculation about how we got here and only have a few incomplete and very recent theories that seem to be closer to the mark. Fortunately our generation is producing some excellent authors that are helping to bridge the gap. I suggest you try out a couple of them. This link is a good start.
Edit: You also seem to be having trouble with the math. There has been some really bad work done showing the mathematical improbability of evolution. Darwin wasn't that great at math either. BUT, there has been some good stuff recently. Try the NOVA video at the top of this page.
As an amazing, beautiful, adaptive, stunning result of 4.5 Billion years of life’s evolution on this planet.
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