Fellow [SBer Tara from Aetiology][tara] pointed me at [this bit of inanity][loonytune], which I can’t resist mocking:
>The mystery of the human genome has come into clearer focus as scientists have discovered that each
>individual person is at least ten times more different than another person than scientists
>previously thought, discounting even further the theory of evolution so widely taught around the
>world. A group of scientists from 13 different research centers in the United States and Britain
>published their findings in scientific journals earlier this week. The results: previous concepts
>that all humans were 99.9% alike were blown apart by the research conducted on 270 people of various
>races that confirmed that 2,900 genes could vary within people, making over a million combinations
>This discovery means that of the nearly 30,000 genes in the human genome that can consist of nearly
>three billion genetic “letters,” 10 percent of those genes can be multiplied in each different
>individual. Instead of being 99.9% alike, humans are more than ten times different from one another
>genetically. Instead of having two copies of each gene–one from each parent–humans have some genes
>that are multiplied several times. Scientists are excited about this discovery, which they say is
>the most revealing since Gregor Mendel’s initial work with the genetic code in the 1860’s.
>Scientists believe it will help them bring about curing individuals who have devastating diseases by
>using their own genetics.
Now, I admittedly have a bit of a hard time parsing this (I guess these creationists are illiterate as well as innumerate). But after correcting for grammar as well as I can, what I end up with is,
to put it mildly, pathetically stupid. Alas, they don’t provide *any* link to a *source* for this, so I can’t be sure of just what the heck they’re talking about, so I can’t completely correct their math. (You need *data* to do accurate math!) But I’ll do what I can. Read on, beneath the fold.
But the basic problem, so far, is… genetically, we say that humans are 99.9% alike genetically – the part of our genes that vary between individuals amounts to somewhat less than one tenth of one percent of our genome. The data that they are allegedly discussing says that there are 2,900 genes
that can vary within people.
What they do with this information is say: 2,900 genes can vary. There are approximately 30,000
genes in the human genome. Therefore, they say, one tenth (or 10 percent) of the genome is variable
between different human individuals.
This is a classic example of innumeracy. When you’re doing math like this, you need to make sure that **your units match**. The 99.9% figure is the number of DNA base-pairs (which is directly proportional to the number of *bits*) in the genome that are the same; the 30,000 out of 300,000 varying in the population is based on the number of *genes*. According to [this page at the NIH][gene-size], the average gene is 10K in bits. So 30,000 genes is approximately 300,000K bits. One tenth of one percent of that is 300K bits. So if the variation between individuals is one tenth of one percent of the genome, that means that there are 300,000 bits of potential variation. (And even *that* is ignoring the fact that the 30,000 number is an estimate of the number of *protein coding genes* in our genome; there’s a lot more to our genome than just the protein coding genes that we’ve identified!)
So, even if we accept the creationists’ assumption that the genome consists *only* of the 30,000 protein-coding genes, is the observation that nearly 3000 genes have significant variation
incompatible with the statement that only 0.01% of our genome varies between individuals?
Certainly not! It means that within the genes that vary, the variations average 100 bits per gene
(roughly 50 base-pairs). That’s not a *lot*, but if we look at real mutations and variations, that’s
not an unreasonable number at all. Remember that even when genes vary between individuals, it doesn’t
mean that *the entire gene* is altered; it means that some *part* of the gene sequence is altered.
Doing a bit of searching, I couldn’t find a statistic for the average size of the variations in the
varying genes, but various mutations that I could find specific data on ranged from a segment of 14
base-pairs to 180 base pairs; and within those, *not* every base-pair was different, but the overall
gene was identical to “normal” on either side of the variation. (For example, one variant was a
*reversal* of a segment of 160 pairs; another was an insertion of a single pair that effectively
altered the gene to the end of the coding region.)
>The research also indicated that humans are far more different than what evolutionists call man’s
>closest cousin–the chimpanzee. Downplayed in any writings about the discovery as covered by medical
>and scientific journals was the finding that instead of being 99% similar to chimpanzees, the human
>is only 94% similar. But given that humans are ten times different than one another, it would seem
>that a four percentage point difference between the chimpanzee and the human genome could mean
>hundreds of times differences between each individual human and each individual chimpanzee. And this
>difference would demolish any reasonable defense of evolution.
Same mistake, pretty much. The estimates of how similar we are to chimps vary depending on the
technique used to measure the difference. Since exhaustive genomes of our species haven’t been available for long, the methods of measuring similarity that have been used can vary somewhat.
The [best recent genome-based comparison that I could find][chimp] found that directly comparable DNA sequences were 99% identical; when insertions and deletions are considered, the two genomes are 96% identical; when specific protein coding is considered, it’s only 29% identical, but the average
variation in the 71% non-identical proteins is *one* amino acid. Not exactly the home-run that
the creationists are claiming, is it?
>Surely, the debate whether the Biblical account of creation is true will continue among the
>scientific community. But the more scientists find, the more the Bible is proven. And in light of
>this genetic discovery, every person who has a child in a school that teaches evolution should rise
>up and demand that this so-called “Theory” be ripped forever from textbooks and be recognized for
>what it is: The secular humanists trying to teach a generation that God is an irrelevant myth.
>Believe it from the Bible or believe it when scientists prove it, but all roads lead to God the
“Debate” about whether the biblical account of creation is true *can’t* continue in the
scientific community. Because there *is* no debate – the biblical account of creation has
nothing to do with the reality of how life developed on earth.