Get vaccinated

It never ceases to amaze me just how many anti-vax people there are out there. Every time I bring up the topic it isn’t the pro-vaccine people who come out in support. No, instead it’s almost exclusively the anti-vax quacks. I suppose the same thing happens with circumcision, 9/11, and a history of Obama’s life: the anti-circumcision crowd, truthers, and birthers are going to immediately overwhelm the discussion. But even with this massive selection bias, the sheer number of nuts out there is incredible. I suspect to see as much regarding this post, should it garner a response at all. However, as a decent human being with a little bit of knowledge, I feel duty-bound to present a few vaccine facts.

Vaccines are incredibly safe. This is true of all vaccines, but especially of the flu vaccine. The most likely side effects anyone is going to suffer are mild soreness or a low grade fever. A study from about 10 years ago did find that one version of the swine flu vaccine from the mid-70’s was associated with a tiny increase in Guillain-Barré syndrome, but correlation is not causation. No one knows why there was such an association, but for this reason those with a history of the syndrome are cautioned and should speak with their doctor to assess their exact situation. Also, those with severe egg allergies are cautioned, plus those who are currently sick with one thing or another should wait.

Vaccines change each year because of evolution. From time to time I’ll hear an objection to the fact that the flu vaccine is different each year. Why, the argument seems to go, scientists are just guessing. That’s not true. While they are making an educated guess, it’s more than just throwing up a prayer and hoping they get it right. Each year’s vaccine is based upon the most recent research and information available. This is necessary because of the speed of a virus’ evolution.

Everyone over 6 months old should get vaccinated. This, of course, takes into account the caveats I’ve already presented, but for the vast majority of people, vaccination is recommended. Vaccines save lives, and if that’s not important enough to you for some crazy reason, they also save money by cutting down on sick days.

The flu vaccine is effective. Exactly how effective the flu vaccine is will vary from year to year, as well as from age group to age group. A person’s overall health is also a factor. In general, though, the vaccine’s effectiveness ranges from 50-80%. The most common (and most annoying) ‘counter’ to this is to look at absolute risk reduction. A person who does this is usually either a quack or has gathered information from a quack. It isn’t that absolute risk reduction is invalid. It’s a perfectly good way to understand how wide-spread a disease or sickness is and how our health policies are dealing with it. For the flu vaccine, the actual reduction in risk is about 1.5%. That sounds miniscule, but we can make a lot of things sound miniscule. What’s happening here is we’re looking at the total population and calculating the number who would get the flu without any vaccine. That’s a very small percentage. Then we’re looking at how likely it is that of the percentage that actually gets vaccinated is going to not get the flu as a result. Again, this is useful. However, when presented in the context of this discussion, it isn’t useful. It would be as if someone argued that since the absolute risk of contracting HIV in Tanzania is very low over, say, intercourse with 5 different partners, the 97-99% effectiveness of condoms is moot. Why, who needs condoms? You probably won’t contract it anyway! Pshaw.

Vaccines, not sanitation, have eradicated or nearly eradicated disease. While it’s obviously true that increased bathing, hand washing, and better filtered water have made us healthier and less likely to contract various diseases, these alone cannot get rid of disease. Smallpox has been eradicated for over 30 years now because of vaccines, not because more people than ever are buying bars of Irish Spring soap. Polio is nearly eradicated because of vaccines; India was recently declared polio free – that isn’t a country exactly known for its impeccable sanitation practices. Yellow fever persists because so many people go unvaccinated (even though the vaccine is 99% effective), and no amount of sanitation is going to change how many people die from it each year since its primary vector is the mosquito.

There are far more thorough sources out there that have vaccine facts covered in much better detail than I have here, so this is far enough for me. I simply wanted to address some of the issues that bother me the most about the vaccine misinformation floating about. For nearly every single person, vaccination is the smart option. The caveats are small and specific, the side effects minor and manageable. Get vaccinated.

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Cornelius “Common Creationist” Hunter

Cornelius Hunter has a history of struggling to understand simply concepts. Today is no different:

As with the so-called vestigial structures—another evolutionary construct—function is, ultimately, irrelevant. A structure is “vestigial,” or DNA is “junk,” not by virtue of any objective criterion dealing with function, but because evolutionists say so.

His post was primarily about so-called ‘junk DNA’, but I’ve addressed that topic in the past, so I will only mention it to note that it only ever betrays a deep ignorance when creationists talk about it. What I really want to discuss is Hunter’s mention of vestigial structures. First, let’s define our term:

[Vestigial] refers to an organ or part (for example, the human appendix) which is greatly reduced from the original ancestral form and is no longer functional or is of reduced or altered function.

Vestigial structures provide a clue to the evolutionary history of a species because they are remnants of structures found in the ancestral species.

It’s easy to see Hunter’s error. A vestigial structure need not be related to function whatsoever – and that doesn’t therefore mean that it is merely the say-so of biologists that makes it vestigial. The human ear, for instance, has vestigial muscles that don’t do anything; in our ancestors (and cousins), their function is to swivel the ear for better directional hearing. That’s vestigial, it’s evolutionary, and it’s science. DNA comparison can, does, and will show that when looked at. Furthermore, a vestigial structure can have a function while still being vestigial. For instance, whales have remnants of hind legs that clearly are not used for walking. However, they do play a role in where muscles are attached. Again, that’s vestigial, it’s evolutionary, and it’s science. Hunter just isn’t familiar with these things.

Jellyfish Lake

Here’s a neat video about jellyfish that have evolved to utilize photosynthesizing algae that produce sugars, in turn providing food for the belled organisms:



These jellyfish are locked in a freshwater marine lake that formed within pieces of volcanic land that ‘sprung’ up in the Pacific; the lake filled in some 12,000 years ago as rising ocean levels reached its basin. With no notable predators (sorry, sea anemone), the jellyfish have reproduced to incredible numbers (10 million by one estimate). They have faced huge die-offs over temperature differences and toxicity levels in years past, indicating that they are part of a fragile environment, but they are currently going as strong as ever.

As evolution predicts, these creatures have lost abilities no longer useful to them. Whereas many of their salt water counterparts are painful sons-of-bitches, the stingers on these guys are closer to being cute than harmful. This, luckily, makes it possible to swim alongside the jellies (and since every article and paper I’ve found on them takes care to note that 15 meters below the surface is a heavy layer of hydrogen sulfide, I suppose I’ll do the same – the stuff can kill you).

Visiting this lake is definitely on my bucket list.

On evolution:

The fact that we all have the same genetic building blocks strongly suggests a single point of origin for all of life. That we can trace our genetic heritage and cousinships in a hierarchical and expanding way which matches morphology, behaviors, and the fossil record helps to make the case for evolution one of the strongest cases for any theory in the history of science.

How should we treat cloned Neanderthals?

Harvard geneticist George Church was recently interviewed by a German magazine where he said that we need to start talking about the ethical and other implications of cloning a Neanderthal. He said that, whereas the technological possibility is foreseeable in the relatively near future, we need to start the conversation today. Unfortunately, English-based media sensationalized his comments and falsely claimed that he was looking for a surrogate mother:

Harvard geneticist George M. Church was quoted in the Daily Mail as looking for an “adventurous woman” to serve as a surrogate for a “cloned cave baby.” The shocking headline spread quickly across the media with no small amount of help from major news aggregators like the Drudge Report…

“I’m certainly not advocating it,” Church told the Herald. “I’m saying, if it is technically possible someday, we need to start talking about it today.”…

Church added that he wasn’t even involved in the particular aspects of the Human Genome Project focused on Neanderthals. Nonetheless, he hopes to use the mistake made by the media for the greater good. “I want to use it as an educational moment to talk about journalism and technology,” he said.

To compound the mistake made by the media, people like Arthur Caplan, writing for CNN, continues to spread falsehoods even after the correction has been made:

Despite a lot of frenzied attention to the intentionally provocative suggestion by a renowned Harvard scientist that new genetic technology makes it possible to splice together a complete set of Neanderthal genes, find an adventurous surrogate mother and use cloning to gin up a Neanderthal baby — it ain’t gonna happen anytime soon.

My beef is with the baseless accusation that Church was being intentionally provocative. Here is what he actually said:

SPIEGEL: Mr. Church, you predict that it will soon be possible to clone Neanderthals. What do you mean by “soon”? Will you witness the birth of a Neanderthal baby in your lifetime?…

SPIEGEL: Would cloning a Neanderthal be a desirable thing to do?

Church: Well, that’s another thing. I tend to decide on what is desirable based on societal consensus. My role is to determine what’s technologically feasible. All I can do is reduce the risk and increase the benefits.

In other words, the magazine asked him all these things. He gave pretty uncontroversial answers, even choosing to take a rather neutral stance when asked if we should clone a Neanderthal. I think the evidence is clear that not only was Church not being intentionally provocative, he was actually attempting to give benign answers.

At any rate, this all does raise the interesting question of how we would treat Neanderthals if we did clone them. Would we give them the same rights and protections? Would we develop a new application for the old scourge of apartheid? I’m not sure the answers to these questions, but I do have some input on how we should go about considering them.

Humans are awfully fond of talking about our special status in the animal kingdom. Indeed, many of us refuse to even consider ourselves animals, disregarding the affront to biology such a stance is. Of course, we have some good reasons for separating ourselves, at least in the context of morality and ethics. Though such practices, common across many taxa, are little more than game theory working itself out amongst genes and individuals, humans take it to another level. So while, for example, our ape cousins will show rudimentary understandings of right and wrong, we have far more complex rules for our society, rules that we can reason out and justify by way of our higher level of intelligence. We are different and that’s important.

How different, though, are Neanderthals? We know a fair amount about them, but they haven’t been around for 20 or 30 thousand years. No one has interacted with them, so a cloned baby would be an experiment in every sense of its life. How different would it be? Would we have criteria established that said, ‘If the Neanderthal is different in these certain ways, it will not enjoy the same rights afforded everyone else under our laws’? I don’t know, but the concern is an interesting one because it raises the issue of why we think we’re so special.

Evolution is a continuous process. We are descended from species which were not human, but at no point did one species give birth to a brand new one. Every mother gives birth to offspring that are categorized in the same way she is. However, when enough time has passed, we’re given the luxury of defining different groups as species within this or that Genus under one or another Family. But look over the tape of evolution and everything eventually converges and lines blur. Just think about human evolutionary history: Back things up 100,000 years and we’re largely the same. How about 150,000? 300,000? 1,000,000? At some arbitrary point we pick, we’re going to start defining significant differences, but if we continually shrink the window of time, the differences start to disappear. (This is all a huge problem, in my view, for the Catholic or other theistic evolutionist who believes only humans have souls.) So from 500,000 years ago to 100,000 years ago, there will be notable change, but that change will be smaller between 400,000 and 200,000 years ago. And the differences become less when we look at our history from 300,000 to 200,000. Keep going and we may be talking about how different our ancestors from 272,000 years ago were from our ancestors living 271,000 years ago. Forget that our investigations into the history of life can’t get that specific. What’s important is that we have to realize there is no line in the sand that says “Species A ends there and Species B begins here”.

So if we do decide that Neanderthals are less deserving of the rights given to humans, we have to admit that humans, at some point in our lineage, were also not deserving. That is, our intelligence and consciousness become more and more comparable to our cousin apes (and now extinct man-like cousins) as we go back in time; we eventually arrive to a point where we would not give our ancestors the same rights that we enjoy. That means we are not inherently special, and I think that’s a major blow to a lot of our assumptions. The supposedly humble Neanderthal shines light on our human arrogance.

Convergent evolution

I was hunting around for some blogging ideas recently when I came across this post by Wintery Knight. It’s basically a copy and paste job because Mr. Knight is not qualified to speak of anything in biology (and he has amply demonstrated as much). However, the person he extensively quotes, Cornelius Hunter, is also 100% unqualified to analyze the world of biology. I’ve written about Hunter in the past.

As in his last post that just barely merited a response, Hunter makes a series of confused remarks about convergent evolution. (For those who don’t know – such as Hunter – convergent evolution is the process by which species of usually distant relatedness will acquire the same trait independent of their last common ancestor.) Let’s take a look at how Hunter mangles this:

The theory of evolution states that the species arose spontaneously, one from another via a pattern of common descent. This means the species should form an evolutionary tree, where species that share a recent common ancestor, such as two frog species, are highly similar, and species that share a distant common ancestor, such as humans and squids, are very different. But the species do not form such an evolutionary tree pattern. In fact this expectation has been violated so many times it is difficult to keep track. These violations are not rare or occasional anomalies, they are the rule.

Hunter is only leading into his mention of convergence here, but he’s already off to an embarrassing start. He’s attempting to claim that we don’t see an expected pattern of descent because that pattern is premised on the idea that similar traits must come from closely related organisms. He is factually incorrect. All he has described here is one method for determining relatedness between species: morphology. And even then, he has grossly over-simplified the process. For instance, take the skull of a dingo versus the skull of a Tasmanian tiger. They resemble each other quite closely, but they aren’t exactly the same. The latter has two holes in the roof of its mouth, a characteristic of marsupials. Go further and one will see that they also have different genetic codings.

Many examples are the repeated designs found in what, according to evolution, must be very distant species. Such evolutionary convergence is biology’s version of lightning striking twice. To explain this evolutionists must say that random mutations just happened to hit upon the same detailed, intricate design at different times, in different parts of the world, in different ecological niches, and so forth.

Were Hunter to take a peak at the genes in a Euphorbia, he might notice that they are markedly different from the genes in a cactus. That’s because, while both plants are prickly desert survivors, one is from the Malpighiales order whereas the other is from the Caryophyllales order. They have significantly different genotypes, but similar phenotypes. In other words, Hunter’s argument that random mutations are always hitting “upon the same detailed, intricate designs at different times, in different parts of the world, in different ecological niches” is not only verbose, but entirely wrong. It would be as though he said home builders have hit upon the same intricate design because some use cellulose insulation while others use spray foam. It’s the same result by a different means.

Everyone has heard of the kangaroo and its pouch. It is a marsupial—mammals that give birth at a relatively early stage in development, and then carry their young in a pouch. There are a great variety of marsupials that are curiously similar to a cousin placental species. The flying squirrel (a placental) and the flying phalanger (a marsupial) are one such example. Because of their reproductive differences evolutionists must say they are distantly related on the evolutionary tree. Yet they have strikingly similar designs which must have been created independently by random mutations. Every mutation leading to the two different species must, according to evolution, have been random (that is, independent of any need). No, natural selection doesn’t help.

First, his mutation argument is still wrong. Second, it isn’t merely reproductive differences that tell us the flying squirrels (which are two independent groups of rodents) are different from the flying phalanger. There is also evidence from their genetic relatedness, not to mention the obvious fact that one is placental and the other a marsupial. Third, of course natural selection is relevant here. That’s the whole reason two species are able to converge on the same solution to similar problems; natural selection has found an efficient solution to one problem faced by two species.

Though evolutionists sometimes deny biological convergence, it is a scientific fact.

I don’t know what Hunter is talking about, but that’s okay because I don’t think he does either.

He goes on to quote from a recent paper:

In mammals, hearing is dependent on three canonical processing stages: (i) an eardrum collecting sound, (ii) a middle ear impedance converter, and (iii) a cochlear frequency analyzer. Here, we show that some insects, such as rainforest katydids, possess equivalent biophysical mechanisms for auditory processing…

Thus, two phylogenetically remote organisms, katydids and mammals, have evolved a series of convergent solutions to common biophysical problems, despite their reliance on very different morphological substrates.

Now, remember the crux of Hunter’s opening: Similar morphology is the same thing as intricate design, thus Jesus. Yet here we see a “reliance on very different morphological substrates”. That is, natural selection in some insects has hit upon the same broad method for attaining hearing as it has in mammals, but it goes about the process in a largely different way, relying upon the insect phenotype it has already given itself. So not only is Hunter’s argument wrong from the get-go, but even if we’re generous and grant him his incorrect basis, he still gets blown out of the water. He has managed to somehow be wrong in his wrongness.

It’s one thing when someone branches into biology from time to time, relying upon the insight of others. We see that with Wintery Knight (the reason being that he hasn’t a clue about the field). We can’t expect everyone to be an expert, even if they should know better. However, Cornelius Hunter is another story. This is a guy who fancies himself qualified and reasoned, able to break down complex scientific ideas. Yet what we see is a man unable to even come remotely close to getting much of anything right about a relatively simple idea. And he keeps trying, getting things wrong every. single. time.

Fun fact of the day

The term “junk DNA” is a misnomer. It refers to DNA that does not code for proteins – only about 2% of genes do that – but it unfortunately implies a uselessness of certain DNA. That really isn’t what biologists mean when they use the phrase (or, rather, when others use the phrase; it has been out of vogue amongst professionals for some time now). All they mean is that we have DNA which appears to have no function. This makes sense in the light of evolution since natural selection wouldn’t necessarily be expected to select against useless DNA. After all, why not just leave it there? Unless it constitutes a substantial energy drain, it doesn’t matter. (Note: I am not referencing conserved DNA.)

However, new research is showing that much of our noncoding DNA does serve important functions. Namely, it regulates the genes that do produce proteins. There is still a substantial portion of the genome that appears to have no function, of course. Moreover, there is useless DNA out there that doesn’t code or regulate anything (microsatellites come to mind). However, we’ll all have to wait for further research before we really know the full nature of the human genome.

The genius of Charles Darwin

By the time that an animal had reached, after numberless generations, the deepest recesses, disuse will on this view have more or less perfectly obliterated its eyes, and natural selection will often have affected other changes, such as an increase in the length of antennae or palpi, as compensation for blindness.

The above quote comes from On the Origin of Species. It is just one of the numerous instances where Charles Darwin, on the basis of his theory, makes a wonderful prediction that comes true so many years after the fact. In this case, his prediction has been shown to be true over and over; species which have gone millions of years in the dark lose their eyesight again and again. We see this especially in many species of cave fish, but it isn’t limited to the oceans:

With a leg span of only six centimetres and a body size of around twelve millimetres, the spider Sinopoda scurion is certainly not one of the largest representatives of the huntsman spiders, which include more than 1100 species. However, it is the first of its kind in the world without any eyes.

“I found the spider in a cave in Laos, around 100 kilometres away from the famous Xe Bang Fai cave,” reports Peter Jäger, head of the arachnology section at the Senckenberg Research Institute in Frankfurt. “We already knew of spiders of this genus from other caves, but they always had eyes and complete pigmentation. Sinopoda scurion is the first huntsman spider without eyes.”

One prediction the theory of evolution allows us to make today that Darwin couldn’t make in his lifetime is that the genes for vision in these now-blind species should exist but be broken. If they do not exist, then either there is some really funky timeline and divergence activity (that is, these are old lineages that evolved before their sighted brethren) and we should see a lot of other genetic differences or evolution just isn’t true. Neither one of those options is very likely, of course. What we observe instead is that, indeed, the genes for vision are a broken, jumbled mess. That isn’t the case yet for the above spider because, as far as I know, no such studies have been carried out, but it is the case wherever else these sort of species have had their genes analyzed.

One point I think that needs to be made sure with Darwin’s quote here is this: Natural selection is unlikely to be the only factor in the disappearance of eyes among these species*. In fact, it could have little to nothing to do with the process at all. Vision in the dark is a useless thing, so natural selection may obliterate it for the sake of saving energy or preventing potential injury to a sensitive body part, but I believe it is much more likely that it simply did nothing. It neither selected for nor against vision. As a result of the lack of positive selection, mutation and genetic drift took over and vision in these species simply faded away.

*I really have two points here. First is the one I just made in the above paragraph. Second is the fact that Darwin was referencing natural selection in regard to it creating some compensation for blindness, not in regard to it directionally causing the blindness.

Chromosome 2

It has been proposed and well evidenced that human chromosome 2 is the result of a fusion event between two chromosomes in our evolutionary past. Briefly, here is the evidence:

All great apes except humans have 24 pairs of chromosomes. We only have 23. That means we need an explanation for such a difference that dates back only a relatively short period of time (5-7 million years). As it happens, human chromosome 2 shows strong evidence of being two fused chromosomes. The way we know this is that all chromosomes have telomeres and centromeres. Telomeres are repeating units of DNA that serve to protect the ends (and therefore middles) of chromosomes, sort of like a good pair of shoes and a strong helmet. Centromeres are DNA units located somewhere between the telomeres of chromosomes, generally relatively close to the center. Their function is to help assemble the two parts of a chromosome during cellular replication and reproduction. In human chromosome 2, we see that there are actually two telomeres fused together in the center. There are also telomeres on the end, but between each end and the center are centromeres. That means we have three telomeres (one of which is fused) and two centromeres.

I bring this up because I was recently reading yet another excellent post by The A-Unicornist and he was dealing with this stuff:

ID is really nothing but an argument from ignorance – it claims that certain things simply cannot be explained by science, so it must be ‘best explained’ by a designer instead. Take for example this post from The New Creationist. I often point creationists to the Ken Miller video where he explains the Chromosome-2 fusion in humans, because it’s a perfect example of the theory of evolution making a falsifiable prediction that ended up being powerful evidence that evolution is true – something that ID has never done and in principle cannot do, which is why it will never be a science. Now, this “new creationist”, who incidentally sounds just as credulous as the old ones, argues that such a fusion is impossible – that the chromosome should never have been able to fuse at all.

Being that I’m not a biologist, I have no idea how to directly refute what he’s arguing. But it’s conspicuously odd that rather than, I dunno, ask a biologist or two (like, golly I dunno, write a letter to Ken Miller?), he simply frames his argument as though the unanswered question itself creates a major problem for the theory of evolution.

Since I’ve used chromosome 2 as an argument for evolution, I am familiar with the creationist responses. As such, I want to address what the blogger known as The New Creationist is arguing:

If the fused chromosomes in an end-to-end fusion are ripped apart by the centromeres during cell division and cells must divide to produce an embryo then how does an embryo develop with two previously fused but now ripped apart chromosomes? We know that the loss of just one chromosome would be lethal and here we have the loss of both of the two
fused chromosomes. If fused chromosomes do not make it through cell division then how could a fused chromosomal configuration be a result of common descent since there would be no descendants by a biological pathway. Such would be miraculous. Indeed, I believe it is a miracle not only because it can not be explained by any natural pathway but also because it is contradicted by experimental data.

What he is trying to say (and what he later says a little more clearly) is that two centromeres would cause division and assembly to occur in two separate places. This would be an all around mess that would prevent not only mitosis, but meiosis as well. So what could the solution be? Well, he answers it himself:

Now, it has been proposed that the deactivation of one of the centromeres in the fused chromosome would prevent the rupture and subsequent loss of the newly formed fusion…

And that is the case. One of the centromeres has been deactivated. One possible reason for this could relate to the fact that the area near the deteriorated centromere (the pericentromeric sequences) has gone through a large number of duplication events, but this isn’t known and requires certain confirming evidence around other deactivated centromeres. I don’t know if any significant research has been done in this area since the 2006 paper about chromosome 2.

The New Creationist continues:

…but this poses another equally lethal problem during the pairing off of homologous chromosomes.

Let’s say that if C2A fused with C2B forming C2 (which has 2 centromeres) in the paternal germ line, the male’s sperm. Now, that sperm would have to fertilize an egg where both C2A and C2B not having been fused would have to pair off with the paternal C2 BUT if C2 has been prevented from being ripped apart because one of its centromeres has been deactivation then the corresponding maternal C2B (or C2A) will not combine with C2 in the mother’s egg because that centromere would have been deactivated.

In other words, he is saying that if two ancestral primates had offspring with the fused chromosome, then that offspring would have 23 chromosomes whereas the rest of the population still had 24. Mating between the two could not occur as a result, thus the fused chromosome could never make it beyond a single generation.

The most obvious solution to this problem is that several members of a population experienced a fusion event. It could have been a completely chance event, or it could have been due to a particular mutation that had spread down the line. That is, my money is on a mutation existing in a population that caused the fusion between two specific chromosomes. Perhaps all the pericentromeric duplications (which pre-date the fusion event, incidentally) gave rise to a gene that was free to mutate neutrally in the population. After some time, it managed to survive the generations, and made a marked difference. (That’s what has happened, minus the specific duplication events, with Richard Lenski’s E. coli.) Or maybe a mutation popped up just out of completely random chance, as opposed to being connected to any particular type of event. It’s hard to say just how any of this happened, but there are good hypotheses to be had on the question.

To conclude, the first argument presented here was defeated before it was even made. One of the two centromeres was deactivated long ago, as stated in the original paper. Indeed, that very paper even suggested a correlating factor in centromere deactivation that could be useful for future research. As for the second argument, I’m going to give Mike the last word:

[T]he fact that an explanation is either unknown or not immediately apparent would not refute the fact that the theory of evolution made this falsifiable prediction, nor would it suggest that there cannot be a rational explanation at all. Our new creationist seems to think that because he does not know how to explain it that a rational explanation is not merely unknown, but in principle impossible. Ergo, Goddidit. That ain’t how science works, kids.

Evolution, fruit flies, and counting

Don’t let any creationist tell you complex things don’t come from simple precursors:

US and Canadian researchers have evolved a population of fruitflies that can count. The result, presented on 9 July at the First Joint Congress on Evolutionary Biology in Ottawa, Canada, supports the notion that the neural mechanisms underlying basic arithmetic skills first emerged hundreds of millions of years ago. It could also eventually offer a key to understanding why some people have problems with numbers…

During a 20-minute training period, flies were exposed to either two, three or four flashes of light — two and four flashes coincided with a vigorous shake administered by placing a electric toothbrush next to the box containing the flies. After a brief rest, the flies were returned to box and shown the light flashes. Despite a dislike for being shaken, most of the flies were not able to learn to associate the negative stimulus with the number of flashes. But 40 generations later, they could.

The researchers caution that the work is preliminary and that they do yet know what genetic changes are behind the insects’ evolved number sense.

What I find interesting is exactly how this constitutes selection pressure. The flies certainly don’t like being shaken, but that’s entirely irrelevant if there isn’t some sort of reproductive advantage to be had from recognizing when the shaking will occur. Clearly there is, and we could speculate all day long as to why flies that associate the flashes with negative stimulus pass on more of their genes than the other flies, but I would like to see some experimental data showing the details. Does shaking disorient the flies? Does it interrupt the mating process? Does it affect fertility? Perhaps the paper that comes from all this can shed some light.

Now excuse me while I go murder the fruit flies that appear to have evolved to make my kitchen just awful for the past week.