I’m not a scientist, so I usually avoid answering specific Creationist claims about the theory of evolution. I prefer to leave that sort of thing for those more qualified. However, there are certain claims that are easily debunked by almost anybody with even a basic understanding of evolution, and I feel that these should be debunked by anybody who is able to do so. If nothing else, it will help to stem the flood of Creationist ignorance on the blogosphere.
The two areas of scientific research which Creationists target most frequently are genetics and paleontology. These two fields are complex and ill understood by most people – they also provide some of the best evidence for evolution, which may be why those few Creationists who actually do know what they’re talking about go after them with such vigor. In particular, the whole area of genetic mutations has been twisted out of shape by many Creationists to such a degree that a geneticist is unlikely to know where to start when presented with Creationist ‘knowledge’ on the subject. In this post I’ll be examining a small fraction of that ignoble corpus, as found in this post. Go and read it first, since I won’t be quoting the entire thing.
‘Problem’ #1: Mutations Are Bad
First is the problem of mutations themselves. Generally speaking, nature tries to eliminate mutations. Mutations are considered a bad thing.
This is probably the single most common Creationist claim on the internet. Either by accident or by design, the whole issue of genetic mutation has been conflated with the popular idea of a ‘mutant’, with the result that many now firmly believe that all or most mutations must be harmful. The sentence above is particularly misleading. While cells have some self-correcting measures which reduce the instance of mutations, ‘nature’ as a whole is not quite so picky. A neutral mutation will certainly not be noticed by most natural processes, while negative mutations will usually be weeded out by a little process known as natural selection. The phrase ‘mutations are considered a bad thing’ is disingenuous – they’re ‘considered bad things’ by a lot of humans, mostly humans who aren’t scientists, but there is no universal principle by which a mutation will always be considered negative.
Mutations are aberrations in nature. That said, mutations can be an advantage, and I see how that could work with natural selection within a species.
It’s true that mutations are ‘mistakes’ in the sense that they represent a fault in the normal process of genome replication, but as I’ve already said, that does not make them necessarily bad. And why should mutations only work properly in tandem with natural selection within a species? Creationists never to seem to realize that admitting to the possibility of micro-evolution is the same as admitting to the possibility of macro-evolution, for reasons that I’ll go into in a minute. There is not some sort of iron wall between the two.
‘Problem’ #2: Mutations don’t happen often enough/something vague about the age of the Earth
Second is the problem of occurrence of mutations. Exactly how often is it that mutations occur? It’s not like every single creature when it reproduces introduces new mutations into the next generation.
I’m curious: how many mutations are needed for evolution to occur? Can any Creationists give me the cut-off point? I’m guessing not.
The rate of mutation is something that Creationists attack surprisingly infrequently, even though it seems like a soft target. It isn’t enough for a mutation to occur anywhere in the body – in order to be passed to the next generation, it must occur either in the gametes (the sex cells – sperm for males and eggs for women) or the ‘germ cells’, which will eventually become gametes themselves. I admit that makes the whole thing sound quite implausible, but those who make it their business to study this kind of thing don’t seem to think so. Besides, we’re not talking about a short space of time here. Evolution occurred over the course of millions of years and has involved hundreds of billions of individual organisms – there are plenty of mutations to go around.
Which brings us to…
But for macroevolution to be true, mutations absolutely must be happening at a ridiculously high rate, otherwise the time needed to get from the supposed origin of life to a human would be monstrously huge. Interestingly the age of the earth continually increases. In 1897, it was thought to be 20-4o million years old. Now we’re sitting at about 4.55 billion. Some of this is due to further research in astronomy and background radiation, but it’s hard not to see a correlation that shows as evolutionary theories progressed and needed more time, so too did the age of the earth get extended.
First of all, there is no reason to say ‘from the supposed origin of life to a human’, for two reasons. It should be humans, plural, since one individual human did not evolve, and it should be ‘from the origin of life to modern life’. Humans are not the ‘most evolved’ organisms on Earth. We are not the end result of evolution, or the top of the evolutionary tree. Nor are we particularly ‘unlikely’, unless somebody would like to propose an objective standard by which to measure the likelihood of a species evolving. This is pure anthropocentrism.
Secondly, and more seriously, there is no Darwinian conspiracy to overinflate the age of the Earth. Creationists frequently categorize science as a whole as existing in order to be a sort of life-support mechanism for ‘Darwinism’, and by extension, atheism. This isn’t just dishonest, it’s downright insane. The entire reason for increasing our estimates of the age of the Earth has been advances the fields involved in dating it, especially those related to radioactivity. This potent force of nature was not discovered until 1896, and it was some time before it was taken advantage of to date our planet. Prior to modern dating methods, scientists were essentially groping in the dark for an answer. Now they have extremely powerful tools that let them know with a high degree of certainty how old the Earth is.
‘Problem’ #3: The Power of Mutations
Third, mutations’ ability to cause change seems vastly overrated. Exactly what kind of mutation can cause a wing to grow when before there was none?
None. Nobody has ever suggested that a single mutation can cause a wing to sprout where there was none before. Mutations largely modify what already exists, and wings are no different – they are modified forms of other appendages, not something wholly new that simply popped into existence with one mutation.
To look at say, a dinosaur, and imagine that it progressed into a bird seems a little far-fetched genetically speaking.
What kind of dinosaur are we talking about here? Because the proposed evolutionary lineage of modern birds is full of dinosaurs that look an awful lot like proto-birds (and proto-birds that look an awful lot like dinosaurs). And according to a strictly cladistic view, modern birds are dinosaurs. Seriously, look this stuff up – nobody is suggesting that some hulking allosaurus morphed into a bird over the course of a few generations.
The biggest problem people seem to have with evolution is that they don’t believe it can produce enough change to bring us from a dinosaur to a bird, to use one example. Of course, they’re usually comparing a generic pop culture ‘dinosaur’ – large, with tiny arms, vaguely T. rex-like – with something like a seagull. Or they pick a completely nonsensical coupling and ask how an ant could evolve into a horse, despite the fact that nobody is suggesting that it ever could. If you’re serious about studying evolution, look at what evolutionary biologists actually say. Yes, it all seems pretty far-fetched if you’re using a cartoonish argument like ‘how could a bacteria evolve eyes and a brain and become a human?’, but the actual evidence is far stronger than that kind of caricatured nonsense.
Imagine a fish that has a mutation to give it leglike fins. This makes it slower in the water, and it can’t escape to land because it doesn’t have lungs (which would have to be another series of mutations). Thus, due to natural selection, that fish get’s eaten. That means the first step towards a fish that can go on land is eliminated. How many of the same mutations must occur so that there can finally be a generation of fish that have the first step of legs without getting completely destroyed by natural selection?
Population genetics is too complex an issue to get into here, and anyway I’m hardly qualified to talk about it, so I’ll direct your attention an excellent book on the subject of the evidence for evolution: Why Evolution is True Jerry Coyne. Another excellent one is Climbing Mount Improbable by Richard Dawkins, which specifically adresses the kind of argument I’ve quote above. (Ignore all of the 1-star reviews, they’re from Creationists with an axe to grind. Here’s my favourite quote from one of them: ‘Using our “obfuscation gauge”, it seems “grindingly, creakingly, crashingly obvious” that Darwinism must have tremendous problems if one of its chief proponents must go to such lengths to prop it up.’ Yes, because that argument always works.) Seriously, these two books alone would cut the number of Creationists in half if they weren’t such an ideologically driven bunch.
And finally, lots more replies to specific Creationist claims can be found here. I’m not aware of any Creationist research that even approaches Talk.Origins in terms of completeness or clarity. And no, Answers in Genesis doesn’t count.