Creationists on Gene Variation

Fellow [SBer Tara from Aetiology][tara] pointed me at [this bit of inanity][loonytune], which I can't resist mocking:

[tara]: http://www.scienceblogs.com/aetiology
[loonytune]: http://www.wdcmedia.com/newsArticle.php?ID=2306

>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
>possible.
>
>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.)

[gene-size]: http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hmg.table.686

>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?

[chimp]: http://www.genome.gov/15515096

>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
>Creator.

"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.

More like this

There is nothing wrong with not knowing something. I dont know lots of stuff. You dont know lots of stuff. Its okay-- we share knowledge with each other. I dont *have* to be an expert in car repair. I dont *have* to be an expert in particle physics. You dont *have* to be an expert in…
Perhaps. But we do other stuff just like chicken (December 09, 2004): ------------------------------------------------ Fantastic news in science: Researchers compare chicken, human genomes http://www.eurekalert.org/pub_releases/2004-12/nhgr-rcc120804.php Some highlights: Chicks have less junk DNA…
Part 12 of my BIO101 lecture notes. As always, click on the web-spider icon to see the original post (from June 04, 2006). Correct errors and make suggestions to make this better. Perhaps this entire series can be included in the "Basic Concepts" series…
Good news! The gorilla genome sequence was published in Nature last week, and adds to our body of knowledge about primate evolution. Here's the abstract: Gorillas are humans' closest living relatives after chimpanzees, and are of comparable importance for the study of human origins and evolution.…

But the more scientists find, the more the Bible is proven.

As well, this is utterly, utterly false. Errors in an opponents position do *not* make your position better. They just make the opponent's position worse. Finding problems with evolution wouldn't prove the bible is right, it would just prove that evolution is wrong.

This needs to be drilled into people's heads over and over and over and over. The major arguments employed by creationists/IDists/etc are all variations on "evolution is wrong, so we must be right!" NO. You have to actually prove that you're right before you become right, not just prove the opponent wrong, unless you are literally arguing about a binary proposition where there are *only* two possibilities.

That is, of course, assuming that the errors you find are even *valid*. Which they are not in this case, as you demonstrated.

By Xanthir, FCD (not verified) on 28 Nov 2006 #permalink

at least ten times more different than another person

What's with "different than"? I was taught "different from."

By Mustafa Mond, FCD (not verified) on 28 Nov 2006 #permalink

humans are more than ten times different from one another

They're not even consistent in their usage.

By Mustafa Mond, FCD (not verified) on 28 Nov 2006 #permalink

Surely, the debate whether the Biblical account of creation is true will continue among the scientific community.

I'm looking over Genesis 1 now and I don't know anyone worthy of the title "scientist" who would agree that "great whales" and "winged fowl" (day 5) appeared before "beast of the earth" (day 6).

By Mustafa Mond, FCD (not verified) on 28 Nov 2006 #permalink

Mustafa, "different than" is common in american usage.

HapMap is a consortium set up for the mapping of exactly where the human genome varies from population to population.

This is useful information for finding which chunks of chromosomes are inherited together, which in turn is useful for finding silent polymorphisms that are associated with certain conditions and also what kind of resolution mapping needs to be done to get the most benefit:work ratio.

You can find them at http://www.hapmap.org/ .

Sadly the innumeracy is not introduced by the creationists. The BBC article on the matter is also unclear as to exactly how the numbers come out. It seems like the scientists-to-media communication link is still a game of Chinese whispers.

It seems this is so new data that the ramifications aren't clear yet.

I found a description ( http://www.the-scientist.com/news/display/36731/ ) there it seems the research consortium behind this pushes for the new analysis that they pioneer. They have developed tools to look for copy number variable regions (CNVRs) in (still rather large) DNA segments.

""I suspect our paper will be a wakeup call to a lot of scientists that they need to start incorporating a 'CNV-analysis step' in their study designs if they want to fully understand their data," Stephen Scherer at the Hospital for Sick Children in Toronto, coauthor on all four papers, told The Scientist via email."

The result is as Mark has described it, some regions contains more variation than earlier comparisons. But there are three more large caveats that the christian news agency didn't tell us.

First, the raw data contains a lot of false positives that needs to be sorted out. "The two technologies combined found 1,447 CNVRs, covering an eighth of the human genome. "We could have culled more CNVs from our data," Hurles told The Scientist via email. However, he said they aimed conservatively "so that investigators are not overwhelmed by the false positives that are inevitable in any study of this nature.""

Second, some of this variation is in "junk DNA" outside coding regions. "The CNVRs contained 2,908 genes, 285 of which are linked to disease. They also contained 67 non-coding RNAs, 50 ultraconserved elements and 130,353 conserved non-coding sequences."

Third, the variations point to different selective pressures, as the existence of disease genes and ultraconserved elements tells us. "The scientists aim to better understand "the new mutation rate of CNVs and how this might be dependent on the region of the genome involved," he said."

By Torbjörn Larsson (not verified) on 28 Nov 2006 #permalink

Oh, and the above description have links to the original research.

By Torbjörn Larsson (not verified) on 28 Nov 2006 #permalink

It's not hust innumeracy that's the problem, it's also reading comprehension of the original article. [and it's not just the creationists who have that problem] What the article does say is that 12% of the genome constitutes Copy number variants among 270 individuals. The 12% of the genome is the cumulative sum of all the possible variants among the 270 samples studied. In other words, if you took any two out of the total number, there would be probably much less than 1% variance between the two. Fig. 3 shows a simplified version of the situation with some individuals having mostly the same except for a duplication at either end. Fig. 7 gives another visualization of the situation with clustering within the three populations used. Also, remember that these are Copy Number Variations with an emphasis on the word copy - which means that the sequences within the copy should be almost identical. How this can taken into account in human genome comparisons is beyond me.

By natural cynic (not verified) on 28 Nov 2006 #permalink

Yet another caveat--the kind of variation the new research has found is very different from the SNP-style variation examined in the past. The latter refers mostly to genes (or non-coding regions) which differ at specific sites or short regions, while the former refers to comparatively long regions, often containing several whole genes, which are copied a different number of times in different individuals. It's hard to see how these can meaningfully be either compared or summed to give a measure of "overall difference."

It's like asking whether

"John Mary Sue Ted Bob" is more similar to
"John Marsha Sue Ted Bob", or to
"John Mary Mary Sue Ted Bob."

Seems to me it'll basically come down to "Whatever makes you happy, popular media."

By Anton Mates (not verified) on 28 Nov 2006 #permalink

I feel this post breaks your habit to give accurate data that you master. It's a bit disappointing.

As one of your last paragraphs states, talking of percentages about genes and DNA is completly dependant on specific aspects you're talking about, and that simply invalidates all the bullshit of the article you debunk. So why do you feel the need to give big numbers about DNA bits and genes ? Genome decoding is such a recent science that these numbers have no real meaning.

This gives the overall feeling that you are arguing just to discredit the people you talk about. Science has always been made of acceptable theories that were proved wrong some time later. Creationism as a whole don't match with current state of the science, but that alone don't mean that it's wrong.

I strongly believe that evolution is the right theory, but I consider creationism as a very unlikely possibility. Everything is possible, you just need enough imagination to make it match with whatever you consider being real.

But the more scientists find, the more the Bible is proven.

I hadn't been aware that the Bible said anything about the amount of similarity between the genomes of humans and chimpanzees.

What Anton said. The real problem is that journalists are completely misreporting this discovery. The hilarious thing is that creationists are now taking that misreporting and spinning it into "evidence" for their position. But what the creationists are discussing is not what the scientists studied at all.

The new data suggests that there is a larger than expected variation in number of copies of a gene between individuals. This is huge support for evolution. Why? Because scientists have long maintained that duplication and subsequent modification of existing genes is a major pathway for the evolution of new functions. If humans are allowed to vary in the number of copies of they have of any given gene, that suggests that some mechanism exists for adding (or removing!) copies of a gene in subsequent generations. This is strong evidence for the first step in the duplicate-modify pathway.

It's also evidence that creationists can only support their ridiculous position by either lying or completely misunderstanding real science.

Doub:

In case you didn't notice, I *am* arguing to discredit the bozo creationists at WDC Media. I haven't read the original article that they garbled into this mess. The entire point of this post is to show that these guys, jumping onto something that they *think* supports their argument for creationism, aren't even capable of doing a tiny bit of research to see whether or not what they're saying is reasonable.

I'm not a biologist; I'm probably not qualified to make much of a judgement on the original publication that spawned this dreck. That's for people who study population genetics. But the way that these idiots *took* the results of that work, and mangled into this mess where even the *grammar* isn't correct, and tried to make it look like it supports creationism by using stupidly bad math - that's very much in
the area where I'm qualified to judge.

Since *their* argument was based on incorrect unit matching, I wanted to show what the results of their kind of analysis would be given *correct* unit matching: so that even being generous, and accepting for the moment that *everything else that they said was correct*, that they're completely, utterly wrong. Their *entire argument* is based on a simple error in units analysis, which is taught in high school math and science classes. If they were even capable of competently doing high-school level math, they never would have issued this little press release of theirs. But instead, they're proudly trumpeting their ignorance and innumeracy to the world. And *that* is what I'm mocking.

As for creationism being "a very unlikely possibility", and "everything is possible...": Have you ever heard that there's a difference between a person with an open mind, and a person with their brains dribbling out of their ears?
Being open minded is no excuse for lending credibility to nonsense. Garbage is garbage, and refusing to judge anything to be impossible dreck isn't open-mindedness. It's stupidity. If I told you that the computer you're reading isn't really operated by electricity, but instead was really a machine with little demons running around carrying messages through tunnels, would you *really* honestly say "Well, that's a possibility, but probably not", or would you say "You're full of it"?

If I told you that the computer you're reading isn't really operated by electricity, but instead was really a machine with little demons running around carrying messages through tunnels, would you *really* honestly say "Well, that's a possibility, but probably not", or would you say "You're full of it"?

It's a series of tubes.

Yes Mark remember.

Everything is possible, you just need enough imagination to make it match with whatever you consider being real.

Facts and reality are only based on what the individual considers them to be. A schizophrenic member of Heaven Gate's reality is just as possible and valid as yours or mine.

You should've mentioned the absurd title of the article: "New Genetic Discovery Debunks Evolution Theory".

Can we catch little demons with internets, then?

Cheers-

"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."

That figure isn't for the genome. It's for protein-coding sequences, a minority of the genome.

A bit like comparing sentences, chapters, and books? Take two editions of a book with 100 chapters. The later edition might have changes to 50 of those chapters. But the actual number of sentences that were changed might be only one out a hundred. So is the book 50% updated, or 1% updated? Depends on how you look at it, but 1% seems by far the more honest figure.

By Greg Peterson (not verified) on 29 Nov 2006 #permalink

the 30,000 out of 300,000 varying in the population is based on the number of genes.

Shouldn't that be 3,000 out of 30,000? I had some trouble trying to follow the math here... ;-)

The thing that still confuses me (and maybe someone can clear up) is the difference between these two statements:

I share 98% (or so) of my genes (or is it DNA?) with a chimp and,

I share 50% of my genes with my brother (or father).

What is the discrepancy and how do these two percentages relate to the number of base-pairs I share with my brother vs a chimp?

"Can we catch little demons with internets, then?"

You need to use intranets. You'd use internets after they escape, but they're much harder to catch then.

"What is the discrepancy and how do these two percentages relate to the number of base-pairs I share with my brother vs a chimp?"

I think that's just the total contribution from the father, from whom you and your brother got half your chromosomes. I don't think that considers differences at the gene level or at the base pair level, which might have occurred for a variety of reasons.

The new data suggests that there is a larger than expected variation in number of copies of a gene between individuals. This is huge support for evolution. Why? Because scientists have long maintained that duplication and subsequent modification of existing genes is a major pathway for the evolution of new functions.

Hmm. Didn't think of that, which I probably should have since duplication is discussed often enough. Which in turn goes back to the potential usefulness of a good journalist, of course. Where are they?

By Torbjörn Larsson (not verified) on 29 Nov 2006 #permalink

is the observation that nearly 3000 genes have significant variation incompatible with the statement that only 0.01% of our genome varies between individuals?

should be 0.1%

Hate those sig figs... ;)

"So God created man in his own image, in the image of God he created him; male and female he created them." Gen 1:27. I guess with all that variation going on, God just isn't very good at what he does. Evidently, he can't make stuff in his image very reproducibly. Maybe the article should have been titled "New Genetic Discovery Debunks Bible".

Reading this page, I realize how innumerate I am. If I hadn't noticed this passage came from a creationist and was told that it came from a scientist I would have not seen the flaws, or questioned the flaws in statistics. The fact that data on gene differences was compared to data on base pair differences in the creationist passage shows just how little the creationists know about math (or are willing to use pseudomath to discount evolution). Then again, weakening evolution is not strengthening creationism.

Reading this page, I realize how innumerate I am. If I hadn't noticed this passage came from a creationist and was told that it came from a scientist I would have not seen the flaws, or questioned the flaws in statistics. The fact that data on gene differences was compared to data on base pair differences in the creationist passage shows just how little the creationists know about math (or are willing to use pseudomath to discount evolution). Then again, weakening evolution is not strengthening creationism.

The thing that still confuses me (and maybe someone can clear up) is the difference between these two statements:

I share 98% (or so) of my genes (or is it DNA?) with a chimp and,

I share 50% of my genes with my brother (or father).

What is the discrepancy and how do these two percentages relate to the number of base-pairs I share with my brother vs a chimp?

You and your brother share 50% of your genes, and also 50% of your DNA, in the sense that (barring germ cell mutations in your mother or father), 50% of your DNA is copied from the same DNA and should therefore be identical. But that doesn't mean that the DNA that you don't share is different. The vast majority of that is the same, as well--it just isn't guaranteed to be identical by virtue of being copied from the same known source. So at the level of DNA sequence comparison, the difference between you will be a fraction of a percent.

90% of the cell in our body are bacterial, therefore...

:-) :-) :-)

Even funnier if you peek on the Loom blog where IIRC Carl Zimmer has posts on that our bodies bacterial genome is 98-99 % (smaller genes), about half our cell genome is viral (DNA from ~ 100 000 retroviruses got stuck in our germ line) and some of that viral genome is reused (for example suspected to be responsible for parts of the immuno-regulation between mother and fetus in the placenta).

What is it to be human (or god), really?

By Torbjörn Larsson (not verified) on 30 Nov 2006 #permalink

I was intrigued by this part of the below-linked press release:

"Despite the growing presence of developmental biology in evolutionary studies, 'Even today, evolutionary theory is very much a theory of adults,' Moczek said. 'But evolution doesn't morph one adult shape into another. Instead there's an entire lifetime of development that we can't afford to ignore.'"

The cited text doesn't mention this, as it is well-known to evolutionary biologists (but probably not creationists) that tadpoles are evolving much faster than frogs. Possibly human infants are evolving faster than human adults.

The field where evolution and devlopment are unified is called "evo-devo" by its advocates.

For more, see:

Vanishing Beetle Horns Have Surprise Function.

Finally, it has been pointed out that God seems extremely enthusiastic about beetles, as their number of species indicates. "Created in his own image" seems a weaker theory than evolution or evo-devo in explaining that.

How do Creationists try to explain away this:

December 10, 2006
Study Detects Recent Instance of Human Evolution
By NICHOLAS WADE
The New York Times
http://www.nytimes.com/2006/12/10/science/10cnd-evolve.html?ex=13234068…

A surprisingly recent instance of human evolution has been detected among the peoples of East Africa. It is the ability to digest milk in adulthood, conferred by genetic changes that occurred as recently as 3,000 years ago, a team of geneticists has found.

The finding is a striking example of a cultural practice -- the raising of dairy cattle -- feeding back into the human genome. It also seems to be one of the first instances of convergent human evolution to be documented at the genetic level. Convergent evolution refers to two or more populations acquiring the same trait independently.

Throughout most of human history, the ability to digest lactose, the principal sugar of milk, has been switched off after weaning because there is no further need for the lactase enzyme that breaks the sugar apart. But when cattle were first domesticated 9,000 years ago and people later started to consume their milk as well as their meat, natural selection would have favored anyone with a mutation that kept the lactase gene switched on.

Such a mutation is known to have arisen among an early cattle-raising people, the Funnel Beaker culture, which flourished some 5,000 to 6,000 years ago in north-central Europe. People with a persistently active lactase gene have no problem digesting milk and are said to be lactose tolerant.

Almost all Dutch people and 99 percent of Swedes are lactose-tolerant, but the mutation becomes progressively less common in Europeans who live at increasing distance from the ancient Funnel Beaker region.

Geneticists wondered if the lactose tolerance mutation in Europeans, first identified in 2002, had arisen among pastoral peoples elsewhere. But it seemed to be largely absent from Africa, even though pastoral peoples there generally have some degree of tolerance.

A research team led by Sarah Tishkoff of the University of Maryland has now resolved much of the puzzle. After testing for lactose tolerance and genetic makeup among 43 ethnic groups of East Africa, she and her colleagues have found three new mutations, all independent of each other and of the European mutation, which keep the lactase gene permanently switched on.

The principal mutation, found among Nilo-Saharan-speaking ethnic groups of Kenya and Tanzania, arose 2,700 to 6,800 years ago, according to genetic estimates, Dr. Tishkoff's group is to report in the journal Nature Genetics on Monday. This fits well with archaeological evidence suggesting that pastoral peoples from the north reached northern Kenya about 4,500 years ago and southern Kenya and Tanzania 3,300 years ago.

Two other mutations were found, among the Beja people of northeastern Sudan and tribes of the same language family, Afro-Asiatic, in northern Kenya.

Genetic evidence shows that the mutations conferred an enormous selective advantage on their owners, enabling them to leave almost 10 times as many descendants as people without them. The mutations have created "one of the strongest genetic signatures of natural selection yet reported in humans," the researchers write.

The survival advantage was so powerful perhaps because those with the mutations not only gained extra energy from lactose but also, in drought conditions, would have benefited from the water in milk. People who were lactose-intolerant could have risked losing water from diarrhea, Dr. Tishkoff said.

Diane Gifford-Gonzalez, an archaeologist at the University of California, Santa Cruz, said the new findings were "very exciting" because they "showed the speed with which a genetic mutation can be favored under conditions of strong natural selection, demonstrating the possible rate of evolutionary change in humans."

The genetic data fitted in well, she said, with archaeological and linguistic evidence about the spread of pastoralism in Africa. The first clear evidence of cattle in Africa is from a site 8,000 years old in northwestern Sudan. Cattle there were domesticated independently from two other domestications, in the Near East and the Indus valley of India.

Both Nilo-Saharan speakers in Sudan and their Cushitic-speaking neighbors in the Red Sea hills probably domesticated cattle at the same time, since each has an independent vocabulary for cattle items, said Dr. Christopher Ehret, an expert on African languages and history at the University of California, Los Angeles. Descendants of each group moved southward and would have met again in Kenya, Dr. Ehret said.

Dr. Tishkoff detected lactose tolerance among both Cushitic speakers and Nilo-Saharan groups in Kenya. Cushitic is a branch of Afro-Asiatic, the language family that includes Arabic, Hebrew and ancient Egyptian.

Dr. Jonathan Pritchard, a statistical geneticist at the University of Chicago and the co-author of the new article, said that there were many signals of natural selection in the human genome, but that it was usually hard to know what was being selected for. In this case Dr. Tishkoff had clearly defined the driving force, he said.

The mutations Dr. Tishkoff detected are not in the lactase gene itself but a nearby region of the DNA that controls the activation of the gene. The finding that different ethnic groups in East Africa have different mutations is one instance of their varied evolutionary history and their exposure to many different selective pressures, Dr. Tishkoff said.

"There is a lot of genetic variation between groups in Africa, reflecting the different environments in which they live, from deserts to tropics, and their exposure to very different selective forces," she said.

People in different regions of the world have evolved independently since dispersing from the ancestral human population in northeast Africa 50,000 years ago, a process that has led to the emergence of different races. But much of this differentiation at the level of DNA may have led to the same physical result.

As Dr. Tishkoff has found in the case of lactose tolerance, evolution may use the different mutations available to it in each population to reach the same goal when each is subjected to the same selective pressure. "I think it's reasonable to assume this will be a more general paradigm," Dr. Pritchard said.

How do Creationists try to explain away this:

I see two textbook creationist answers to the above. The first is that if Creation was 6000 years ago, they get to call the research nonsense and therefore dismiss it out of hand.

The second is subtler - that humans have indeed changed - but only within the original design parameters and therefore it isn't evolution as no new information has been added.

(Of course, this second is less likely to be chosen than it would in other circumstances because it means that people who aren't lactose intolerant have devolved - and most American Evangelical Christians are not lactose intolerant...)

Mark C. Chu-Carroll wrote, "Because there is no debate - the biblical account of creation has nothing to do with the reality of how life developed on earth."

Nothing? Not even in a poetic sense?

And whoever wrote this is correct:

"Everything is possible, you just need enough imagination to make it match with whatever you consider being real."

Such is of the essence of poetic understanding, not meant to be confused with scientific understanding; confusing the two modes is the cause of many unnecessary arguments between religion and science (sadly, most religious folk make this error, as do some scientists).

So the Biblical account isn't science and isn't meant to be taken literally. This doesn't mean that it's meaningless. It's a fable with metapphorical resonances as far-reaching as the mind can entertain ... just don't mistake it for science.

"So the Biblical account isn't science and isn't meant to be taken literally."

So says you, normbreyfogle. But a large percentage of people in the US would disagree with you. They really believe Biblical accounts of creation, and unfortunately, they've managed to muster enough money and votes to actually have an impact in this country.

I believe that any time religion makes a claim to knowledge, whether it be historical or otherwise, we have a duty as rational, reasoned humans to hold it up to the light, and compare it to what the best versions of reality science has to offer us.

It's a fairly modern concept to not take the Bible literally, and the main reason is science. As science has enlightened previously dark corners, those dark corners have been increasingly claimed to be mere metaphor, by the most reasonable of Christian believers. Others trudge on in spite of these facts, but either way, religion and science are often in conflict, and until there is a religion that can allow for flexibility in it's doctrine, to allow it to grow with our knowledge of the universe, there probably always will be.

The only other options that would end the constant friction would be an *actual* revelation from an omnipotent being(at least one who can get the basics of science down) or the miraculous disappearance of the worlds relgions. I'm not counting on either of those though.

By DumbMonkey (not verified) on 19 Feb 2007 #permalink