Friday, March 9, 2012

Pander Bear: how much should we tolerate?

So now the Hype-O-Mat is in full force, with the media hacks taking stories from the science panderers about how the new (Exciting! Transformative!) gorilla whole genome sequence will (Finally!  At Last!) tell us everything you (or your friends, neighbors, and relatives) ever wanted to know about humans.  Your every thought explained by one hairy beast's DNA!  The BBC, usually or at least sometimes a tad more responsible than other media, is the vehicle for perpetuating enough hype about this Nature paper to make you want to reach for the air-sickness bag, especially when you look at the video that accompanies their story. (Just the first of many statements demonstrating deep misunderstanding about evolution: "In the distant past, humans were not very different from gorillas."  What were they actually trying to say?  That humans were once gorilla-like, as though gorillas have not changed through evolutionary time, but humans have?  Or, to give them the benefit of the doubt, that humans and gorillas share a common ancestor?  Unclear.)  Maybe this is getting such play because it's largely a UK sequencing effort that generated the new data.  But you can be sure Nature is eating it up -- and indeed you don't need a subscription to see the gorilla story touted on the front page above the fold this week.

Scientists are expert at toeing the line between responsible reporting and hype.  In print.  We cover our bets so we can't easily be found wanting by our peers.  So, the authors of the paper can argue that they aren't hyping their results when they write things like this: "The use of the genome sequence in these and future analyses will promote a deeper understanding of great ape biology and evolution."  No over-promising there, they'll say.  But, on tape it's a different story.  They say things such as that gorillas don't get dementia, and their genomes will tell us why, and lead to a cure in humans.  And so on.  Oddly enough, the chimpanzee genome sequence hasn't told us why humans are human, or lead to miracle cures, and they're even closer to humans.

Indeed, the argument is that the human genome is only 2% different from our closest ape relatives. Close enough to let us figure out what makes us human.  But this is drivel.  Think about it.  Humans are closer to humans than any other ape, but each copy of our genome differs from each other copy by a few million bases, a fact well and specifically documented with modern sequence data.  Can we use those to tell us what makes one person different from another?  Or what about comparing Chinese and French genomes to see what makes the former use soy sauce and the latter eat truffles (that's culture, after all!).  Or why one person is good at math and another at play writing?

Never mind complex diseases (like dementia). And in fact if you don't just compare two copies, but ask how many nucleotides vary in someone in our species, the answer is probably nearly all of the 3 billion.   The tiny 2% difference people talk about between humans and other apes means 6 million base pair differences, again only comparing one copy from each species. Now we know that many traits like disease can be caused by a single base-pair change, so that playing the number game is, well, just a marketing game. 

These nucleotides (could) "hold the key to the human condition", if what we are is in our genome and if a gorilla sequence alone can tell us what the meaningful differences are.  Now, it is OK to say that a gorilla sequence will be potentially useful and will be interesting in understanding aspects of evolution of primates and that includes humans, and indeed, that is said in the paper.  Since we're clearly a bit more closely related (with more recent descent from common ancestry) to chimps than gorillas, it is not totally obvious how this will "hold the key" to our entire condition.  But what might it hold?

Of a set of genes that someone finds, or imagines they've found, that relate to our behavior or intelligence (our "language, culture, and science"), one could see whether orangs, chimps, or gorillas share variants that we have as well but that are different from the corresponding sequence in monkeys.  That would suggest that those variant states are not responsible for our language, culture, or science.  Or a candidate gene's sequence might be shared between gorilla and chimp, but not us (or, say, Neanderthal fossils).  Such variants would have arisen specifically in our lineage.

Conserved sequence elements, that is, elements that haven't changed among ape species are potential indicators of things too important for change to have been tolerated.  But those reflect what has had to stay the same, not what makes our culture.  And much hasn't changed because, given mutation rates and population sizes, there just hasn't been enough time, whether or not there's an important function.  And if a single nucleotide change could be favored by selection, and there are countless millions of differences, well, you ask yourself how such hype ever makes it past an editor's desk.

This is the most rosy, positive kind of spin one can put on such findings but of course the hype machine, and those driven to prematurely announce 'the' gene responsible for our language, culture, and science are eager to indulge.  Such preposterous nonsense should be resisted, first of all by the scientists, very skilled at their job, to make sure that they do not seem to be endorsing such silliness (one gene to explain the human condition?  Or is it 3 genes?  17?).  As long as it seems likely to encourage the sponsors to keep their wallets open (NIH and in this case the Wellcome Trust--a pharmaceutical foundation that is supposed to be supporting health-related research), investigators can't resist the cuddly Pander Bearing opportunity.  Without accountability, who can blame us?

There are so many other reasons to object to the hype that we won't bother to continue, and the points have been made by us and many others.  It is the over-selling of what is interesting, potentially useful knowledge as if it represents something transformative.  It transforms science into bullshit (to use a technical term).

The gorilla genome sequence represents another bit of data we have to work with in studying our evolution and genetics.  Like many other kinds of knowledge, it could contribute to important advances in understanding.  But that's true of almost any kind of data about life.  Claims like this story's are close to the line of outright lying by otherwise respectable scientists, or else by journaists who are either unqualified or dishonerable.  The pander bears cry wolf so often that we in genetics will have richly deserved to have our funding deeply cut, if the austerity police come round looking for fat.

We bet that even a gorilla has genes, somewhere in its now revealed genome, that make it smart enough to see through such posturing.  Chest-beating is one of the tricks in their genomes, after all!

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