The science of Confusapedia

Ok, so the science entries on Conservapedia are easy targets – finding mistakes is like shooting fish in a barrel. And quite a few of my fellow science bloggers have engaged in target practice lately. But not all the entries are grossly biased. Some probably sound quite plausible to the layperson. Like this one:

Mutations are changes in the genetic code caused by copying errors, or by external factors such as solar radiation or exposure to mutagenic chemicals. Mutations are sometimes the cause of disease, such as cancer or Down’s Syndrome (which is the result of an extreme mutation which causes an extra chromosome to be present). Evolutionists claim that heritable mutations produce genetic variety, upon which natural selection acts. However, mutations can only decrease information, never increase it.

source: Conservapedia: Mutations

(Accessed Feb 26, 2007 – nothing over there is stable, it kinda. . . mutates).

In my opinion, it’s entries like these that are most insidious, because there are no obvious red flags. They seem unbiased, simple, factual. And increasingly, students accept whatever they find on the internet as fact. (I don’t care if it’s Wikipedia or Conservapedia: it’s not ok to cite a site, especially those that change as often as wikis do!) Few of my college biology students would have picked up on the problems in this entry. I’m going to walk through it; this information will be nothing new for those readers who are biologists, but I think it’s an eye-opening exercise to see how easily the misinformation slips through and how hard it is to explain why it’s grossly oversimplified, if not wrong.

First off, it’s properly Down syndrome, although the s is frequently blurred in pronunciation, so many people think it’s Down’s. I can understand that – I spent several days in Edinburgh and never figured out I was on Princes Street, rather than Princess Street. Not a huge issue – although a reference like an encyclopedia should weed out such trifling errors.

A more misleading statement is categorizing trisomy 21, which causes 95% of Down syndrome cases, as a mutation (which has just been defined as a change in the genetic code). “Trisomy” is the presence of an extra, unaltered copy of a chromosome, which has not undergone changes in its base pair code. There is nothing “mutant” about this extra chromosome. Trisomy is a simple sorting error, as if you did your laundry and started grouping your socks by threes instead of two. The individual socks are normal, it’s the grouping that’s the problem.

Only about 5% of Down syndrome cases involve actual changes to the genetic code: translocations or duplications of various parts of chromosome 21. Only these atypical cases of “familial” Down syndrome should really be considered mutations. Citing Down syndrome as a representative example of a disease caused by mutation is a bizarre choice, especially given the plethora of diseases caused by single-base changes in a gene. Sickle cell, cystic fibrosis, Tay-Sachs. . . the list goes on.

On the other hand, in order to associate these diseases with mutations, you need to accept that the disease-causing alleles of each gene arose as mutations of the original, functional allele. In other words, the genes evolved. It gets worse: the alleles were selected over time according to the principles of population genetics, such that the diseases mentioned above now occur in well-known geographic or ethnic patterns. In other words, natural selection acted on heritable genetic variety created by mutation – just as those darn evolutionists claim.

But Conservapedia denies that mutation can produce heritable genetic variety. At least at its current level of dialogue, it does – I’ve actually seen single-gene disorders erroneously cited as evidence that mutations can only be destructive (disease-causing), never constructive (evolution-causing). Speaking of which, let’s look at the final line:

However, mutations can only decrease information, never increase it.

If you accept that single-base changes (mutations) occur in genes at all, then you have to accept that these alterations will change the information coded in the gene. But “decrease the information”? I don’t think that wording makes any sense, unless you’re talking about a deletion of part of the gene. If you lose three base pairs, then yeah, I guess you’ve decreased the information by three base pairs. You could also increase the information by adding in three base pairs. Neither “increasing information” or “decreasing information” accurately describes how the gene works. A mutation that alters a gene so it no longer works does not “decrease information.” It alters the information, such that the gene’s functionality is decreased. That’s a heritable variation right there: a nonfunctional copy of a gene can produce a phenotype like colorblindness that is inherited.

This “information” wording is probably chosen to exploit our intuitive preconceptions about information as the creation of an intelligent author. It’s difficult to imagine how random changes to a gene could improve its function, just as it’s hard to envision how random changes in a book would improve the story. An better way of stating the Conservapedia position would be “mutations only decrease functionality, never improve it.” That’s a common impression among my students, because it is intuitive. Generally, when you make a typo, it’s a mistake, not a new word (I think it’s still information, though). You expect a typo to be a mistake. And if you’re using Microsoft Word, they get cleaned up, or at least flagged so you can go back and fix them.

But sometimes Word doesn’t catch a typo. Why not? Because you’ve accidentally typed an unintended, but valid, word. You’ve changed the information in the sentence. The sentence may still make sense. It could even be better than what you originally intended. This might be a rare outcome, but it’s certainly not impossible; I know it’s happened to me before. And it’s just as possible for a mutation in DNA to improve the functionality of a gene, or change it to something new.

As every teacher knows, it’s quite difficult to explain complex biological concepts at a novice level. And it’s hard to pin down how this Conservapedia entry gives the wrong impression. But it does. A reader could well be left with the idea that a mother who gets a sunburn risks both skin cancer and having a baby with Down syndrome. That makes no sense.

Unfortunately, I don’t think we should acknowledge that Conservapedia has largely been written by students, and just let it go, like New Scientist did. The creators have chosen to present the site as an equally authoritative alternative to Wikipedia, not a student project. And the most troubling thing is, it’s more accessible than Wikipedia. I love Wikipedia, but in the quest to be comprehensive yet precise, its contributors have done what I just did (on a smaller scale): add information and clarification until entries are long and full of jargon. Plus, hyperlinks are used to the fullest. This keeps individual entries nonredundant, but on the other hand, reading an entry outside your comfort zone often demands dipping into ten or twenty other entries to learn the unfamiliar terms used in the original entry. This even happens when, we suspect, vandals infiltrate Conservapedia and mess up the content – those entries become more conceptually difficult than the unvandalized ones. Oh, those nutty, naughty scientists, with their big words.

At this point poor Conservapedia has been pretty well scrambled – not only are its entries being fiddled with, it’s down much of the time. But even so, as a put-upon student writing a much-procrastinated paper, would you rather encounter the Conservapedia paragraph above, or Wikipedia’s entry on mutation? Here’s a brief taste of Wikipedia:

Gene mutations have varying effects on health depending on where they occur and whether they alter the function of essential proteins. Structurally, mutations can be classified as:

Small-scale mutations affecting one or a few nucleotides, including: Point mutations, often caused by chemicals or malfunction of DNA replication, exchange a single nucleotide for another. Most common is the transition that exchanges a purine for a purine (A ↔ G) or a pyrimidine for a pyrimidine, (C ↔ T). A transition can be caused by nitrous acid, base mispairing, or mutagenic base analogs such as 5-bromo-2-deoxyuridine (BrdU). Less common is a transversion, which exchanges a purine for a pyrimidine or a pyrimidine for a purine (C/T ↔ A/G). A point mutation can be reversed by another point mutation, in which the nucleotide is changed back to its original state (true reversion) or by second-site reversion (a complementary mutation elsewhere that results in regained gene functionality). These changes are classified as transitions or transversions. An example of a transversion is adenine (A) being converted into a cytosine (C).

Obviously, no reference can be equally accessible to readers at every level of education. But I think we should probably acknowledge that while we laugh at Conservapedia, it’s got its target audience pegged. And that could be a real headache for educators down the line.