/* Conversation about: https://www.youtube.com/watch?v=4PKjF7OumYo */
I'm often puzzled by people who insist they don't "believe" in evolution. There is nothing to believe. Once you understand the biology behind DNA replication and natural selection, evolution becomes self-evident. The only wiggle-room for anti-evolutionists is the length of time over which evolution has been taking place. Some believe it's a matter of a few millennia, while the evidence tells us it's more like a matter of a billion years.
Ash, it's a lot more complicated than that. The more you know how complicated and interconnected the processes that make up even just a single are, the more it seems unreasonable that life should even exist at all. We don't really have good evidence of increases in complexity, but we assume that the mechanism works because it's the only reasonable naturalistic explanation. (Random selection actually works against evolution, as selection trends towards the 'average', not to mention mutation causes more problems than it solves, research is currently turning to viruses as the potential sources of complexity increases but I digress). The biggest issue I have with evolution is that it's reasonableness is mostly based on a priori assumptions within the scientific method: that being, there is an implicit assumption that the supernatural does not exist. So of course, if we rule out the supernatural then evolution is the most reasonable explanation. But if we relax that assumption then evolution is on pretty shaky ground.
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So, a couple of points. Given the massive scale of the universe, which is awesome in the true meaning of the word, it doesn't really surprise me that life exists. We have demonstrable evidence of how species evolved from earlier species, showing how natural selection leads to diverse, more complex life. Evolution isn't based on "random selection", as you assert – mutations are random, but whether or not organisms who inherit those mutations survive long enough to breed is anything but random.
Science does not assume that the supernatural does not exist, but since it cannot be measured or quantified, science ignores explanations from supernatural sources. Instead, it focuses on explaining natural phenomena through laws of nature. You have to admit that this has been to humanity's benefit: things that have been previously attributed to the supernatural have now been demonstrated to be natural phenomenon. Take the Earth. Whilst older societies believed the Earth was flat, or a disc on the backs of elephants standing atop a tortoise, or any other myth, we now know that the Earth is a celestial object no different from other planets in the solar system and universe. Based on that knowledge, we have worldwide satellite communications, GPS, and a plethora of other technologies that we just could not have developed without challenging the supernatural explanations of the time.
This has lead to a kind of "god of the gaps", a phrase I'm sure that you're familiar with, but I'll explain for anyone else's benefit. Say we have something that can only be explained by invoking a supernatural source. Take the weather for instance. When people ascribe the source of weather to a god, then we discover a natural explanation for weather, people stop believing in the supernatural explanation. The gap in our knowledge has been filled, and only the remaining gaps in our understanding remain in god's domain.
Remember, evolution doesn't explain the origin of life, just the process of speciation. All organisms on Earth share a common ancestor. If you want to believe that life itself, that original common ancestor, has a supernatural origin, I think that's a valid opinion to hold. Believing in supernatural causes for natural phenomena is reasonable, as long as it doesn't impede our search for quantifiable explanations (which help advance our society, as shown above).
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Ignoring explanations from supernatural sources is the same as ignoring the supernatural, especially with respect to the scientific method. I don't see the point in quibbling over terminology in that regard-- even if we had empirical evidence of supernatural activity, we'd have to ignore it to satisfy the naturalistic assumption. Don't get me wrong: I'm not arguing about the utility of naturalism, I'm questioning it's veracity. It's inarguable that it's a useful assumption to make, though it's worth pointing out that almost all of the earliest scientists were theists themselves, and varied in degree from extremely christian (Mendel was a monk after all!) to deists, some of whom argued that it was humanity's responsibility to understand the universe that God made and to uncover the rules that He put in place.
All that to say faith is not necessarily in conflict with scientific reasoning, but scientific reasoning starts from different assumptions, and those assumptions will necessarily lead to different results, and it's important to recognize that regardless of how good science has been at explaining many things, it does not have a monopoly on truth, especially if some explanations require supernatural sources. (Again, we do need to avoid 'god of the gaps' scenarios, but my point is, if we can determine that a supernatural explanation is justified to explain a certain phenomena, then it's foolish to ignore it) If the naturalistic assumption (however reasonable) is not true, it undercuts one of the main supports for evolution. Not many scientific theories are affected this way, for example relativity (enabling the GPS system) wouldn't be affected because of the empirical evidence surrounding it, whereas evolution has always been accepted more on merit of it's explanatory power than on actual empirical data.
Again, you have to be careful about the underlying assumptions in arguments: All life has DNA. DNA has been analyzed to construct a tree of similarities and differences. Evolutionary theory suggests that this tree represents the effects of evolution over time. However, it could also be interpreted as a simple comparison of the 'code' across different species. If you did that for programming projects today, no one would assume that greater or lesser similarities had particular importance, but of course we would expect that programs with similar functionality or appearance are more likely to have similar code. In the same way, 'single common ancestor' analysis doesn't necessarily mean that there even ever was a single common ancestor, just that if we extend current rates of mutation back into the past, that's how far that we'd have to go before the code could have been the same. However it doesn't deal with the functional aspects: If evolution exists, it has to go by leaps, not incrementally, due to the interconnected nature of many complex biological systems-- especially when higher-order organisms are concerned. If you look at the data, evolution has been demonstrated in microbial species quite often as it is very simple to add a novel trait to bacteria, or to take any minor code change as significant when the DNA is compact, but it's never been demonstrated to scale: the timescale for changes is too large, and the fossil record cannot be complete by it's very nature. However without evolutionary theory there would be no overall framework to relate species to each other, and so in the end, due to convenience and the naturalistic assumption, evolution becomes the most reasonable explanation. Even so, there are a huge amount of headaches that come with attempting to fit data from higher-order organisms into the evolutionary model which I would argue suggest that it is not an appropriate model for higher-order organisms in the first place, however others could counter it might just be that we don't yet know how to do the analysis properly. I'm of the belief that all known naturalistic processes to explain life fail to sufficiently explain higher-order organisms, so either there are other processes that have not yet been discovered, or there are no processes whatsoever and we are the product of some sort of intelligence. As for abiogenisis, that's an entirely other kettle of fish, but suffice it to say that earth has never had the proper environment for abiogenesis to occur, and current research is turning to the idea that life must have been seeded from space somehow. We are exhausting all reasonable naturalistic explanations!
My point in this verbosity is not to prove or disprove evolution, it's simply to point out that evolution is only 'self-evident' with a particular set of a priori assumptions, which may be reasonable but are not necessarily true, and it's important to realize that.
As an aside, since we exist, life must be possible, however that doesn't necessarily mean that life is a common thing: It's impossible for us to know how probable life is given only our own planet, and without any observations of life spontaneously coming into existence. All we know is that, due to our existence, the probability is greater than zero. How much greater is anyone's guess at this point.
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You continue to demonstrate fundamental misunderstandings of the basic theory of evolution, either through ignorance or wilfulness, so my assertion that "you either understand evolution or you don't, there is not need for belief" holds true.
classy ad hominem. Believe me, the more you know, the more you realize that 'the basics' are not quite true.
Excuse me, there was no ad hominem. I stated a fact.
/* And then I unfriended him, because ain't nobody got time for that. */