Liveblogging at "Building Complex Brains"

I'm in beautiful Fiskebäckskil on the Swedish west coast for the 5th Kristineberg symposium "Building Complex Brains" at the Kristineberg marine research station. We arrived yesterday to check into the hotel and enjoy the incredible welcome dinner, but the talks started this morning. The town is right by the sea, the hotel we're staying at is quite nice and the weather has been with us, warm and sunny, so I'm loving it so far. The research station has free WiFi, unlike the hotel, so I'm taking advantage of our extended lunch-break to get a few words down, upload some photos, check some e-mails and so on.

I'll expand on this post during the conference to comment on some of the talks I've heard today. So far, very very interesting stuff, and quite useful for my work. Looking forwards to the forthcoming 3 days of evolutionary neuroscience talks, nice food, sun, sea and socializing.

>Update June 12

The first session of the day was on the subject of evolutionary developmental biology or EvoDevo. I noticed that I'm a lot more familiar with "Evo" than with "Devo", those cell-types and developmental stages flew right over my head, but quite a lot of things stuck with me and very interesting stuff was presented. The second session was on neurotrophic factors, factors that regulate the survival and growth of neurons, a subject I'm not familiar with so it wasn't as rewarding.

I'll just quickly put down some brief impressions and thoughts on the talks that I found particularly interesting.

The first talk was on the evolution of different neuron types in the nervous system. The work presented by Detlev Arendt of the European Molecular Biology Laboratory in Heidelberg highlighted the importance of identifying and comparing homologous cell-types across animals, from the very simplest nervous systems in animals that diverged a long long time ago to the more complex ones in animals that diverged more recently (evolutionarily speaking), to understand how new functions and complexity emerged in the evolution of the nervous system. The focus was on the marine bristle worm Platynereis dumerilii.

The general pattern that appears is that in the early stages of nervous system evolution, neurons had multiple functions, then as these ancient multifunctional neurons generated new "daughter" neurons in evolution, the functions were distributed in a complementary way.

What's interesting for me, is that they have identified nerve cells that release the neuroendocrine peptides vasotocin, gonadotropin-releasing hormone and proopiomelanocortin in Platynereis dumerilii. These are hormones that serve a multitude of functions in our physiology, and there they are in a worm brain. Fantastic. Vasotocin is a member of the oxytocin/vasopressin protein family and since I'm studying the evolution of the oxytocin/vasopressin system in vertebrates, this insight is quite exciting. Obviously this system has a very interesting and very ancient history.

Going back to ancient neurons having multiple functions, the vasotocinergic neurons also express light-sensitive receptors, opsins, like the ones we use for seeing. Does this reflect the ancestral function of the hormones in the oxytocin/vasopressin family? Did this system originate as a signal in the regulation of circadan rhythm or time-of-day-dependent behavior? Are these vasotocinergic cells in Platynereis really the equivalent to the vertebrate oxytocin/vasopressin cells? They seem to express the same profile of genes, but I can't completely discard the thought that it could be a whole different cell type in the worm using the same basic gene "scaffold" as the vertebrate cells.

The next talk was probably the most rewarding because it involved an organism that's very interesting for my work - the lancelet or amphioxus, the most basal close relative of the vertebrates. Jordi Garcia Fernandez of the Universitat de Barcelona presented a perspective of what the study of the genome sequence of the lancelet might give us, in particular with regards to the evolution of the nervous system and body plans.

The position of the lancelet in the evolutionary tree of life makes it very important. By comparing its genome with vertebrate genomes we cover the entire scope of vertebrate evolution and gain the possibility to understand a lot about how the primitive organisms that would evolve into the vertebrates worked. The problem so far has been that the genome sequence has not been assembled; in the database that has been available you can only see a mess of fragmented pieces of sequence which makes you miss a lot of information. So it was very pleasing to hear that the assembled genome sequence as well as the release article will be published next week. I've done quite extensive searches in the database that is currently available, looking for the gene families I'm interested in, but it hasn't provided any information. Hopefully the assembled genome sequence and the first analysis will give me some answers. I'll hold on to some thoughts that came to me during this talk until I've had the chance to read the article on the preliminary analysis.

There was a very interesting sidestep during the talk about the concrete experimental possibilities that are opened up once you know more about the lancelet genome. By targeting the specific developmentally relevant genes and producing genetically engineered animals, it would be possible, at least in theory, to replicate what took millions of years of mutation and natural selection and generate typically vertebrate features in the lancelet. One such feature could be the development of limbs, for instance. It's a captivating idea, but only time will tell if its application lies anywhere in the near future.

A subsequent talk by Shigeru Kuratani of the RIKEN institution in Kobe treated another organism at a very pivotal point in the evolutionary tree - the lamprey. The lamprey, as it compares to other vertebrates, is the living representative of early vertebrate evolution. The lamprey brain lacks some of the features that characterize most vertebrate brains, so the questions that comes naturally is, when did particular features of the vertebrate brain arise and what does the lamprey brain actually reflect? I didn't understand a lot of the developmental biology involved, but it appears that the basic plan and gene expression of the vertebrate brain was already established by the time the first vertebrates came along, which is very interesting.

Even though I don't know much about neurotrophic factors, I found one of the talks in the second session quite interesting. Neurotrophins guide the growth of neurons and regulate neuron survival and death. This has consequences for the development of the nervous system but also for the plasticity of the brain, roughly its ability to adapt itself, memory and cognition. There are two models how brains are "built" - either a finite number of components are produced and put together in a determined fashion, much like a Lego set, or an excess of components are produced followed by a process of adjustment and trimming of the excess. It is in the latter model of brain development that neurotrophins play an important part. Alicia Hidalgo of the University of Birmingham, presented the finding of neurotrophins in the model organism of all model organisms, the fruit fly Drosophila. Invertebrate brains are generaly thought to lack neurotrophic factors, their brain development was regarded as a "Lego set", "hard wired" with little room for adjustment and plasticity. Finding this shared feature between an insect and "higher" organisms opens up for the thought that there is one basic "brain building" model and that it very early on included the foundation for the very advanced and adaptable brain that is present in vertebrates.

>Update June 13

I'm in the middle of a talk about fruit fly smell receptors - multitasking is my thing. The two sessions today have been about genomics, and sensory systems and behavior. The genomics session especially really touched on some pretty interesting questions; I'll update this post after dinner sometime if I have the energy. I updated yesterday's post this morning instead of last night 'cause dinner was so rich and plentiful and included ever re-filling glasses of wine as well as brandy after dessert, so we'll see what happens today.

I've uploaded more pictures on a Flick set; this one is of the research station where the symposium is held.



>Update June 14

Today, the last day, is all about the cortex and the evolution and development of the human brain. There is only time for one session in the morning before lunch and the departure from Fiskebäckskil. I think I'll have time to upload the rest of this post before then, and if not, possibly on the train or when I get back home.

The best talk of the day was held by Ann Butler of George Mason University on the subject of the evolution of the brain circuitry that is thought to underlie conscious experience and higher cognitive functions. In a way, the red thread through the presentation was sort of "the search for cognition" in non-human animals and what it could tell us about the evolution of our own cognition. Now, cognition is a very tricky thing to define - it's a typical problem of having the brain trying to understand itself - but a certain type of electrical activity in the networks that form connections between the brain cortex and thalamus, as well as certain anatomical features of the connections have been correlated to cognition. The cortex is the outermost and evolutionarily "newest" part of the brain, and the thalamus is a more central part that to a large extent functions as a sort of "relay station" of pathways.

The really interesting part is that these special features, or components of them, have been demonstrated in animals as diverse as birds, turtle, frog and fish. So it's possible to "test" the nerve networks thought to underlie cognition in ourselves to the equivalent ones in other animals. Especially birds have demonstrated astonishing cognitive abilities - there are some famous examples: "Betty the crow" can make hooks out of pieces of wire to collect a piece of food; Alex the African grey parrot could recognize colors and shapes as well as quantities up to six and maybe even had a concept of "zero", among other things. When one lines up a chart of the complex networks that are thought to underlie high cognitive functions in humans and birds, the similarities are striking. The challenge is to understand how the similarities and, importantly, the differences are telling, how to stimulate the experimental animal in a way that is relevant to it and make the proper comparisons, and what this as tells us about the evolutionary processes that gave rise to out cortex and our cognition.

The thread was taken up by the following speaker, Jon H. Kaas of Vanderbilt University, who talked about early mammal brains and what they can tell us about our own brains. The successive increase in brain size in our lineage, and the increase in the number of nerve cells that this entails, underlie the complex interactions and regional specializations that make our abilities possible. The comparative studies of small mammal brains, theoretically similar to the original early mammals' brains, could offer us clues to how our complex sensory and motor systems emerged - how we experience the world and how we react to it.

Finally, we heard from Svante Pääbo of the Max Planck Institute for Evolutionary Anthrolopogy in Leipzig on the subject of the genomic perspectives on human origins. I've written about his research on the FOXP2 gene before, but this was a more general talk, only using FOXP2 as an example. A lot of it was on the progress of the sequencing of a neandertal genome, but also of course about how comparative analyses of the human genome and the neandertal genome will shine a light on a very crucial point of our evolution. Will we be able to identify genes that were important in our evolution? Will we be be able to define what it is that makes us specifically human? It's difficult to pinpoint what makes us "so special" when more and more of those traits we jealously guarded as "ours" appear in traces in other animals - perhaps looking at the genome, rather than looking at our behaviors and abilities, will be the key. But to do so we need to know more about that last step in the road to where we are today.

Swedish blog tags: Vetenskap, Biologi, Evolution, Neurovetenskap, Hjärnan
Technorati tags: Science, Biology, Evolution, Neuroscience, Brain

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"Put a Little Science in Your Life"

This op-ed from The New York Times, Put a Little Science in Your Life, is well worth reading.

A COUPLE of years ago I received a letter from an American soldier in Iraq. The letter began by saying that, as we’ve all become painfully aware, serving on the front lines is physically exhausting and emotionally debilitating. But the reason for his writing was to tell me that in that hostile and lonely environment, a book I’d written had become a kind of lifeline. As the book is about science — one that traces physicists’ search for nature’s deepest laws — the soldier’s letter might strike you as, well, odd

But it’s not. Rather, it speaks to the powerful role science can play in giving life context and meaning. At the same time, the soldier’s letter emphasized something I’ve increasingly come to believe: our educational system fails to teach science in a way that allows students to integrate it into their lives.

I won't contend that the tone is a bit... missionary; but past an initial instinctive negative reaction, I don't think there's necessarily anything wrong with that.

We all apply science in our daily lives, consciously or unconsciously. It's a very basic human endeavor. So why wouldn't it be alright to make an emotional argument for it as well as an intellectual and practical one?

The reason science really matters runs deeper still. Science is a way of life. Science is a perspective. Science is the process that takes us from confusion to understanding in a manner that’s precise, predictive and reliable — a transformation, for those lucky enough to experience it, that is empowering and emotional. To be able to think through and grasp explanations — for everything from why the sky is blue to how life formed on earth — not because they are declared dogma but rather because they reveal patterns confirmed by experiment and observation, is one of the most precious of human experiences.

Science is not a dry, laborious and meticulous practice best left to experts that dwell in tiny mundane details. On every level of practice, it's is a powerful, beautiful and satisfying way of regarding the world, the universe and our existence within it. So if you can make people aware of the fact that science, a perspective that everyone is already using every day of their lives, is within their grasp, can inform their existence and resonate within them on an emotional level, it's worth being accused of a little bit of religious fervor now and then. But unlike the fervent missionary, the fervent scientist has empirical knowledge, reason and inquiry in his/her belt to back up the "message".

Swedish blog tags: Vetenskap
Technorati tags: Science

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More platypus

I've been poking about a little bit extra in the platypus genome for a week now in response to the platypus genome release article I wrote about in my previous post. It was a pleasant surprise to notice that so many of the gene families we are interested in in our lab have distinguishing features in the platypus. It has the neuropeptide Y7 receptor, which is absent from other mammals; it has a unique galanin receptor that I've been looking into some more; it has the shortwave-sensitive-2 opsin gene, the visual pigment that detects blue light, which is absent in other mammals (we have modified the ultraviolet-light-detecting opsin to see blue light instead)... it's pretty interesting stuff.

I missed this BBC article last week. It's not spectacular, but it has a nice audio interview with professor Jenny Graves at Australian National University, co-author of the genome release paper. I liked this highlight of what we are able to learn about evolutionary transitions by looking into and comparing genomes:

The platypus is a mammal, it makes milk and it has fur so it is defined as a mammal, but it left the rest of the mammals a long time ago. It diverged 166 million years ago from a common ancestor that probably looked more like a reptile than a mammal. So it's not a reptile, it is a mammal but it's retained a lot of reptilian characteristics like laying eggs for instance... Of course one of the things we wanted to look at was egg-laying and making milk because we want to retrace the steps in how did we get to be mammals? and so first of all we looked at the egg yolk proteins and indeed there is an egg yolk protein there, but there's only one of them whereas birds have three for instance. So it looks as though the platypus is already shifting its allegiance from nurturing their young inside an egg and nurturing their young with milk.

There have also been quite a few blog posts concerning the platypus, which is fun. Pharyngula and Adaptive Complexity both have very comprehensive posts and both also take issue with the purported image of the platypus as a composite creature, "part bird, part reptile, part mammal"; Genomicron and Nimravid focus on the problem with calling the platypus "primitive" or defining its characteristics as "reptilian" or "avian"; Carl Zimmer just wants to know where the platypus' stomach went and The Digital Cuttlefish shares with us a few inspired words.

Swedish blog tags: Vetenskap, Biologi
Technorati tags: Science, Biology, Genomics, Platypus

Continued >>

Ph34r the platypus!

Proof that god has a sense of humor? Or simply an amazing creature whose unique combination of features are the result of an intriguing evolutionary history? You guessed it.

Not that we needed another reason to love the platypus - looking something like the cross between a beaver and a duck, being venomous, endemic to Australia and one of the two mammals that lay eggs is awesome enough - but now that we have its genome sequence (the release-paper having been published yesterday in Nature) we have the chance to learn a lot about how modern mammals evolved from more reptile-like beginnings.

The New York Times writes:

If it has a bill and webbed feet like a duck, lays eggs like a bird or a reptile but also produces milk and has a coat of fur like a mammal, what could the genetics of the duck-billed platypus possibly be like? Well, just as peculiar: an amalgam of genes reflecting significant branching and transitions in evolution.

In short, there are elements and patterns in the genome that are very similar to those in birds and reptiles and others that are decidedly mammal.

Several "reptilian" genes involved in vision, circadian rhythm and food intake are present in the platypus but have been lost other mammals, while of course the genes for the milk proteins caseins and their arrangement are as mammal as can be. Some of the genes for the proteins that coat the egg-cell before fertilization are shared with other mammals while others have only previously been found in fish, amphibians and birds - just to give some examples.

But even though its apparent mix of features is reflected in its genome, the platypus is not "part bird, part reptile, part mammal" like some popular science outlets sloppily have written. Science Daily and New Scientist really should know better. The platypus is a representative of a group of mammals that diverged from the rest of the mammal lineage at an important transition from more reptile-like creatures towards modern mammals. By comparing, for instance, our genome with the platypus genome we get an insight into how that transition took place. That's precisely why it's a beautiful addition in our understanding of how evolution has put genomes together. Not because it's a "lizard-bird-mammal" in any sort of way.

There are also some pretty cool unique features to the platypus genome. It has a lot of genes for odorant receptors that cannot be found in other animals - possibly to detect water soluble odorants when it forages underwater, or maybe as part of a highly advanced pheromonal system? I mentioned in the beginning that platypuses were venomous (the males inject the venom through a spur on their hind legs) - it turns out that the proteins that make up the platypus venom are not a "reptilian" character but have evolved independently in reptiles and in the platypus.

I have been using the preliminary platypus genome sequence in my research for a while now, trying to figure out how the genes that make up part of the brain's endocrine systems have evolved. It's been a nice addition to my evolutionary trees and I count on it to continue to be very useful in the future.

>> Edited May 16, 2008.

Warren, W.C. et. al. (2008). Genome analysis of the platypus reveals unique signatures of evolution. Nature, 453(7192), 175-183. DOI: 10.1038/nature06936

Swedish blog tags: Vetenskap, Biologi
Technorati tags: Science, Biology, Genomics, Platypus

Continued >>

Brief report

A brief report on this the International Worker's Day. It seems I haven't been up to that much lately, as April is completely blog-free, but somehow my time has been filled up.

I've been to a couple of interesting seminars and lectures. One with Eric Lander, major initiative-taker behind the human genome project, about how these are some pretty exciting times to be a biologist. We are learning how the inner workings of life, genomes, are "built" at an ever increasing speed. Nothing will ever be the same from here on. We will potentially gain the power to understand, cure and prevent disease but also to understand ourselves and our place among all living things a lot better. Really "pepp" as we say in Sweden. Encouraging and motivational.

Then there was a lecture with biologist, author and teacher Per Kornhall about the intelligent design movement in Sweden. I wasn't fully aware of how methodological the attack on evolutionary theory is in the Swedish school system, even though I have encountered it several times. Particularly how larger evangelical organization use Christian student associations to get into the schools. Per wrote an excellent book called Skapelsekonspirationen (The Creation Conspiracy) which is, I think, the first one on the subject in Swedish. Even though we don't have a big ID movement here, it does rear its ugly head more and more often so a book like this is needed.

What else have I done... I gave a seminar at our department about my research project, it went pretty well. I've graded some exams... And of course I've been out enjoying the sun which has finally started to grace us for yet another (all too brief) summer season.

Case in point, yesterday was Valborg (Walpurgis night), the big student celebration of the year. Uppsala is Valborg HQ every year so the whole city was one big party from early morning 'til late night.

This is what happens when you start drinking at 9 in the morning.



Hahaha, I don't even know what was going on there but I'd had a considerable amount of champagne.

I spent the day with friends drinking champagne and having strawberries and cake for breakfast by the river, watching the student-made rafts crash downstream. Then picknick lunch in the sun at the park and in the evening we had a big rooftop BBQ. We couldn't have had a better time.

To finish off, some thoughts on May 1st. I've grown up going to the Worker's Day demonstrations every year. I hated having to go, being dragged there by my parents when I was little, but today of course I see it in a different way. I don't like getting tangled up in politics and I don't go to the demonstrations anymore, but if there is something I take the time to consider it's this, and I encourage everyone to do the same - everything you own was made by someone, often someone in a third world country, often someone that doesn't have access to many of the things and opportunities that you have and take for granted, often someone living in squalor, often a child. Remember that nameless faceless worker today.

Peace!

Swedish blog tags: Valborg, Första maj, Kreationism, Per Kornhall

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I'll tell you why

I got this (anonymous) comment to one of my recent posts countering creationist claims.

But why so terribly arrogant? If you believe you are right, some humility would make it better. The way it is now, it appears to be along the line of "when the arguments are weak, speak louder".

This is a fairly common response to vocal scientists countering any kind of pseudoscientific claims. I see it over and over and on occasion, like now, I have it aimed at myself. First of all it's really rather tiring and, just for the record, I don't think my retort was very arrogant at all. But putting that aside, it's the sort of critique from the peanut gallery that has little validity to the question at hand.

If there are two mutually incompatible views, they cannot possibly both be right. When one of them is nothing but misleading illiterate nonsense, ignorant distortion of facts or outright dismissal of them, it just doesn't merit the kind of "humble" and respectful response advocated by those who feel scientists are too arrogant. In this case, the kind of creationism I countered in my posts deserves nothing but the ridicule and severe rebuke it got. To approach it "humbly" would be to play right into the creationists' hands. It would be to concede that both views are equal and deserve equal attention and respect and that they play on an even field, which is 100% not the case. True humility is to approach questions of science unprejudiced and objectively, which creationists most certainly don't. Who are the arrogant ones?

As I wrote in my retort's concluding remarks;

This [creationism] is not about challenging science. This is not about wanting to bring science forward. This is not about one scientific view arguing with another. It's so very easy to forget that. This is about religious proselytes wanting to destroy a product of rational thought because it challenges their deeply held world-views. For all the science that is involved, for all that I have written in these entries, in the end this is about fanatics wanting to tell us all how we should lead our lives because they patronizingly feel that they have the moral authority to do so. No scientific theory pretends to do the same. The mere thought is utterly ridiculous. But by arguing like this, creationists want to take down evolutionary theory to their playing field. It's important that we don't lose sight of that.

So really, who are the arrogant ones?

Creationists thrive on the "when the arguments are weak, speak louder"-argument and they love nothing more than playing the underdog card whenever they can. Unfortunately a large portion of the general public plays along with their dishonest outcries for humility. When I said that the critique presented in the above quoted comment was not valid to the question at hand, I meant it, but that doesn't mean to say that I don't take it seriously. It is of course unfortunate if the scientific rebukes are seen as arrogant by the general public and if they only reinforce the view of creationists as underdogs. This is often coupled with the fact that scientists speak out from a position of authority, which in any situation is readily mistaken for arrogance. But the solution is definitely not to concede to their tactics and give the impression that science and creationism offer equally valid explanations. The solution is to bridge the disconnect between science and scientific thinking and the general public. It's maybe in that department that those of us who vehemently rebuke pseudoscientific claims have failed. But ultimately dreck is dreck and it needs to be called out on it, forcefully and vocally.

Swedish blog tags: Pseudovetenskap, Kreationism
Technorati tags: Pseudoscience, Creationism

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Retort to a creationist lecture pt. 3

This is the third and last post in a series examining the lecture given by creationist author Anders Gärdeborn this past February 14 at Uppsala Universitet, by invitation from evangelical christian student organization Credo.

So finally I get to post the last part of my retort. Most of it has been done for quite a while, I just needed a little time to finish off the very last part. The other posts in the series have been:

First thoughts on yesterday's creationist lecture here in Uppsala
Retort to a creationist lecture pt. 1
Retort to a creationist lecture pt. 2

I'll now continue reviewing Gärdeborn's presentation of so called scientific evidence against evolution. Concluding my examination with what I think are the two most interesting fallacies creationists make - the distinction between "microevolution"/"macroevolution" and the concept of "biological information".

Evolution "within kinds"

In yet another line of misleading statements about evolution, Gärdeborn means to say that "evolutionists" have drawn conclusions from the existing biological diversity that are unreasonable. He wants to separate the "how" and the "why" in science and says that we would probably agree as far as the "how" goes, it's evolutionary theory's "why" he has a problem with. In other words he means to say that in the descriptive study of the diversity of organisms and organismal complexity we have taken too many liberties when drawing conclusions as to how the diversity and complexity have come about. He gives an example: "Bacteria become resistant, therefore we come from bacteria". Gärdeborn might think that this is a pithy point with rhetorical finesse, but I have a hard time imagining a clunkier or more confused distortion of scientific thought, much less a more willfully mean-spirited one.

Gärdeborn cannot deny that some biological change takes places, but that it happens through natural selection acting on diversity is to him "only a theory". That all life has a common ancestry he calls a "philosophy". That last remark merits a little sidetrack. All organisms on earth, that we know of, have the same nucleic acids in their DNA as well as the same orientation on their amino acids, one out of two possible. This and some other well-known properties of life makes the scenario of one common ancestor the most likely one by far.

Back to the point. It's not surprising that creationists recognize some form of evolution. After all, there are many examples of biological change through evolutionary processes that lie within the time frames that are easily manageable to our thought. These are difficult to deny, even for creationists. Examples are how bacteria become resistant to antibiotics and how we have bred different breeds of dogs. The advocates of creationism have even made up a word for these more visible processes - "microevolution" - one assumes to avoid the concession of calling it just evolution, quite simply. It's quite puzzling that somehow it's allowed for evolutionary theory to explain how a poodle and a German shepherd had a common ancestor, but not how humans and chimpanzees could have had the same. The criteria for this division have no scientific grounds whatsoever. "Microevolution" and "macroevolution" are the same thing.

What's remarkable about Gärdeborn's presentation is how far he's ready to extend "microevolution" into time frames that are well within the realms of the "macroevolution" that creationists so categorically negate. He describes an evolution "within kinds" caused by some sort of pre-programmed "genetic potential" that he fails to describe more closely. God created the "kinds" and after the deluge, when they repopulated earth, they diversified into the species we observe today. (By the way, this is his explanation of how two of every animal could fit in the ark. They were two of every original "kind", not species.) Gärdeborn affirms assuredly that in nature "animals exist within determined groups" and gives canids as an example. He says that there are "waterproof bulkheads" between the groups ("there are no half-people") but that variation can arise within the groups through "microevolution". It would be interesting to know why such a large and diverse group as the canids can be seen as a waterproof grouping while such a small one as the apes cannot. At the core of this reasoning is the fallacy of thinking that evolution has happened as transitions between the species of today.

The canids include dogs, wolves, foxes, coyotes, dingos, jackals, African wild dogs and a variety of other species. According to modern science, they arose from the miacides, a sort of dog- and bear-like carnivores, about 40 million years ago, relatively early in the evolution of mammals. This is supported with fossil, morphological, genetic and protein data. The evolution of the great apes goes back approximately 14 million years but still their (or I should say, our) evolution is regarded as an unacceptable "macroevolution" while the 40-million-year-old evolution of canids is an acceptable "variation within kinds". Of course creationists don't recognize the evolutionary time scales, but even if we just take the genetic and molecular data into account, the difference between a fox and a wolf is far greater than the difference between a human and a chimpanzee. Gärdeborn counters this as it's presented to him during the questions and answers session after his lecture. He says that evolutionary theory incorrectly assumes that likeness is due to common ancestry. But isn't this the same thing one has to assume to speak of "microevolution" within "kinds"? Where, one might ask, is the logic between this distinction between "micro-" and "macro-"?

The answer is of course that the creationist "kinds" have no scientific validity whatsoever. Fact is that all divisions into species and genera and so on are purely artificial... of course. Species don't exist in and by themselves in nature so that we might "discover" them. They are divisions we have invented in order to describe nature systematically in a way which we might find useful. Our order- and structure-obsessed brain reveals itself once more. It's important to note that this sort of division is not without its problems. Species and even larger divisions such as genera and families can be significantly blurry around the edges and difficult to determine precisely.

Biological "information"

Gärdeborn's last great argument is the one of biological "information". It refers mainly to the genetic code and how specific sequences of nucleotides are translated into specific sequences of amino acids making up proteins with different functions. "Information" is a monster of a concept, so clouded by lay interpretations, misunderstandings and alternative definitions that I sometimes question if it's even useful in biology or relevant in the creationistm vs. evolution debate. What's apparent is that the term has been adopted by creationists first hand, not by biologists.

What creationists, among them Gärdeborn, even mean when they refer to information or how they suggest it could be measured is still in the dark. Whatever it is they mean, it seems to be a vague and somewhat metaphysical quality that you somehow recognize when you see it. Gärdeborn reflects exactly such a conception in his formulations: "We need information". "Information can never be derived from energy and matter, it's something more". They might not say it straight out, but it becomes painfully clear that what they mean with information is purpose and design, nothing else. There must be a consciousness and an objective behind it, otherwise it's not information because it wouldn't be informative. Gärdeborn expresses this as - "information requires an informer and an intended receiver". Consequently the creationist conception of information has been defined from the beginning as something that necessitates a creator. This is nothing more that the argument from personal incredulity or ignorance again. Just as creationists can't comprehend how organisms can be so apparently purposeful without being designed by a higher power, they can't comprehend how the genetic code can be so well-determined without a willfully inserted information. Science understands how this is possible and evolutionary theory has provided us with the answers that we have.

That's not to say that there aren't any scientific definitions of information. Most of them lie within computer science and IT and have to do with how information is sent and received. The definition that is most applicable to the genetic code was made by mathematician Claude Shannon and outlined in the 1948 article A Mathematical Theory of Communication. According to Shannon, information can be defined through probability. A high content of information is linked to a high improbability. Our genomes could then be said to be carriers of information since it would be very improbable that they would assemble into such a precise sequence of nucleotides all on its own. It bears the mark of improbability. But this "mark" doesn't need a supernatural explanation. It's natural selection that has shaped the causal relationship between genetic sequences and function.

The question that remains to be answered is whether or not the concept of information, in the scientific sense of the word, is applicable to genetic sequences. It's undeniably very inviting to define that which is "encoded" in our genomes as information, as instructions to how our bodies should be built and function, since it's a term that is easily understood in everyday terms and that ably attempts to describe how genomes function. But it carries with it a series of problems. The information is not really there. Whatever can be "interpreted" from genetic sequences doesn't really have a "language", none of the grammar or syntax that creationists seem so eager to point out is there. Instead, it is DNA's physical and chemical structure that create the causal relation to its function. The concept of information is nothing but a projection of our brains' preference for structure and organization on a process that can best be described as a causal relation.

The concept of information is something that we more or less "force" upon genetic sequences in order to describe it, and not a property of it in itself. In the best of cases it can help us visualize the process in a readily understandable way. But it the worst of cases it very easily leads to serious misunderstandings and misinterpretations.

The creationist definition of information (that from the beginning assumes there is an all-powerful informator) and the scientific definition of information (one of them) overlap to a certain extent, but for the most part they are completely incompatible. It's unfortunate that sometimes the term is used to retort to creationist argument without defining it clearly first. This is definitely true in the case of the creationist claim that evolutionary theory can't explain how new information can arise, which Gärdeborn brings up. He is unconvinced that evolutionary theory can explain how completely new organs or structures arise. The creationist definition of information is made so that it automatically confirms this claim. Innovation, it seems, must come from god.

It's difficult to argue against such a bluntly one-sided challenge. But with a solid understanding of evolution and of genetics it's not very difficult to understand how new information arises and is passed from generation to generation if it confers advantages to its "carrier". Duplications of individual genes, larger blocks of DNA, even whole pieces of chromosomes or whole genomes, are an important motor in evolution. Whole genome duplications are very common in plants, where new variants and species may come to be very quickly, but they have also occurred several times in animals.

Duplication of a gene enables one of the copies to change over time at a faster pace that the other copy since the original function can be preserved. The copy is a "buffer" of sorts for innovation. It's been proven many times over that this has been an important contributor to the introduction of "new information" in evolution. Creationists claim that this isn't true innovation since it builds upon something that's already there. This reveals a deep ignorance on how evolution works. All innovation generated by evolutionary processes has happened through small stepwise changes, over an immensely long period of time, of something that's already there. I would be hard pressed to find evidence anywhere of a genetic sequence with a determined function that has just appeared out of nothing. In short it means that genetic sequences can be "kidnapped" into fulfilling other functions than the one it was originally adapted to. This principle has received the unfortunate term "preadaptation", with its teleological undercurrents, but it can also be called co-option. This gets a larger throughput in a scenario where a duplication has occurred and the "redundant" genetic material can be "kidnapped" into carrying out a new function.

What creationists also fail to see is that even if both copies change at the same rate and don't evolve into different directions, a duplication might still confer advantages to the organism since it increases the amount of gene product. This is also an introduction of "new information".

The demonization of evolutionary theory

I won't dedicate a lot of time to the more extraordinary claims and interpretations made during Gärdeborns more theological second half of the presentation. Suffice it to say that it was suggested that the earth is 10,000 years old, that the grand canyon was created by something like a volcanic eruption, that Neanderthals had rickets (osteomalacia) due to vitamin D sufficiency, that all animals were vegetarian until the original sin introduced death and that we conserve a "collective memory" of the deluge. The last claim was corroborated by the Chinese symbol for "boat" which apparently is made up of the symbols for "eight", "people" and "container". There were eight people in the ark. Do you feel that eerie tingle down your spine yet? Yeah, me either.

Crazyness aside, what really infuriates me to no end is creationists insistence on demonizing evolutionary theory with distasteful, inequitable and untrue claims. Gärdeborn had no qualms in explaining that his purpose was to discredit evolutionary theory because he sees it as an obstacle in humanity's way towards finding god. First of all, what nerve! What incredible condescension! He continued this despicable preachy streak by affirming that evolution undermined the notion of all people's equal worth. Since god created man to his own image, man has a special place and all human beings have equal value. So in effect Gärdeborn claimed that evolution, by "demoting" humans to mere apes, promotes death, racism and willfully undermines compassion, solidarity and morality. God on the other hand doesn't want death (he merely allows it?) but is a god of life and love and compassion.

Many people that are much more versed than me have answered to these ridiculous claims so I won't even try to. I'll leave it to you to make your own judgment. I feel I've spent too much energy and time on this already. But I wanted to conclude with the above paragraph because I think that it illuminates what this whole discussion is about. This is not about challenging science. This is not about wanting to bring science forward. This is not about one scientific view arguing with another. It's so very easy to forget that. This is about religious proselytes wanting to destroy a product of rational thought because it challenges their deeply held world-views. For all the science that is involved, for all that I have written in these entries, in the end this is about fanatics wanting to tell us all how we should lead our lives because they patronizingly feel that they have the moral authority to do so. No scientific theory pretends to do the same. The mere thought is utterly ridiculous. But by arguing like this, creationists want to take down evolutionary theory to their playing field. It's important that we don't lose sight of that.

Swedish blog tags: Vetenskap, Evolution, Biologi, Pseudovetenskap, Kreationism
Technorati tags: Science, Evolution, Biology, Pseudoscience, Creationism, BPSDB

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FOXP2 and the evolution of speech

I mentioned briefly in my post from yesterday that I prepared a literature seminar in the undergraduate neurobiology course for this past Thursday and Friday. It was on a very popular and well-developed topic that really doesn't merit much additional commentary. But since I spent so much time preparing for it I thought it would make sense to just very quickly type something down and produce an entry for the blog.

The subject was FOXP2 and the evolution of speech. FOXP2 is a gene that has been linked to some faculties of speech and language, the media going as far, as they do, as calling it "the speech gene". It isn't a terribly current or "right now" topic, but it highlights many aspects of evolutionary neuroscience and it spans everything from genetics and development to evolution to behavior and society so it lends itself to interesting discussion.

I wrote down some questions to use as a guidance in the discussion but I didn't hand them out to the students beforehand 'cause I thought that they'd be more free to take the discussion wherever they wanted, it being such a wide-spanning subject. Apparently that was a mistake. The first group of students was very quiet, frustratingly so, and I had to do most of the talking. I think they found the articles difficult. I can understand that, but they were supposed to be challenging. The purpose of the seminar is to give some training in critical reading of scientific literature. This does take some effort and maybe they would have needed some concise questions to guide them. I gave the second group the questions and 15 minutes to prepare some answers at the beginning of the seminar and they did so much better. So that's something to consider for the next time.

I centered the seminar around a general review article from a few years back, a couple of short reports on recent FOXP2 evolution, one of which is about the controversial subject of Neanderthal gene sequencing, and a really nice article from last year on FOXP2 in echolocating bats (first 4 references below). All the students got the review article and one half got the reports while the other half got the bat article. My thought was that we could take the discussion from the anthropocentric notion of FOXP2 having evolved in the human lineage to produce our "superior" faculties of speech and language and warp it towards bats and how FOXP2 seems to have evolved in their lineage as well to produce their unique use of vocalization for echolocation. Along the way we also discussed some general concepts of molecular evolution, the neuroanatomy of speech production, the definition of speech and language, the emergence of culture and the selective advantages of evolving such a complex means of communication.

First some introduction.

The FOXP2 gene was first identified through the study of the so called "KE family" in the late 90s. This is a family in which a severe speech and language disorder affects almost half of the members. This case was interesting because the disorder segregated from generation to generation in a pattern that pointed very decisively towards there being just one gene causing it. You can see a pedigree of the KE family below. Shaded symbols indicate affected individuals.


Ref: S.E. Fisher et. al (see reference below)

The researchers were able to identify the region on chromosome 7 that was associated with the speech disorder and subsequently they were able to identify the gene. Even though FOXP2 should not by any means be called "the speech gene", its identification and study has given us an "entry way" into the very complex processes that govern speech and ultimately perhaps language.

These are the questions I prepared for the seminar with my own answers, adapted for an undergraduate biology crowd.

1. What is the function of the FOXP2 gene product? How does it act?

FOXP2 is a transcription factor, a protein that binds to DNA and regulates the expression of a variety of specific genes. In the case of FOXP2 it's still unknown which ones. FOXP2 in particular represses the expression of genes. The fact that it's a transcription factor puts it in a place of particular interest for several reasons. (1) It makes it probable that it's central to the processes that underlie speech. (2) Small changes in a transcription factor can give rise to major innovations because they influence a wide variety of genes and thus functions. (3) Transcription factors have dual roles - they act during development, setting up structures and functions, as well as in the mature organism, regulating the same. This mirrors the complex development and plasticity of speech.

2. FOXP2 is an extremely conserved gene in vertebrates. What does this mean? Can you relate this fact to the FOXP2 protein function?

The word conserved means that there is very little sequence diversity between lineages. In other words, there is extremely little difference between the crocodile FOXP2, chicken FOXP2 and human FOXP2. Transcription factors are generally more conserved since they have a very basic function - even the smallest change could have enormous consequences since transcription factors regulate a wide variety of genes and functions, but also because they act during development.

3. FOXP2 was related to speech by the study of individuals with speech abnormalities (particularly the KE family). How are their FOXP2 genes aberrant?

The KE family has a substitution from arginine to histidine on position 553. This affects the DNA-binding region of the protein, leaving it useless. Another patient has a premature stop codon that leaves the protein too short to function and yet another patient has a translocation in the region containing the gene.

4. Why is it useful to study FOXP2 in vocal learning birds and bats? What are the main findings in this regard?

The implication of FOXP2 in brain regions involved in bird song learning are considered parallel to the human vocal learning of language. Young birds, just like us, mimic the sounds that adults make in order to learn them. It has been found that FOXP2 expression is increased in periods of song learning. These seasonal periods of plasticity could mirror the development of the neural circuits that make vocal learning possible. However no specific mutations have been related to this specific ability (including the study of vocal learning echolocating bats) and expression sites of FOXP2 are not different when comparing vocal learners with non-vocal learners.

5. In which brain regions is FOXP2 expressed? To what faculties of speech and language can you relate FOXP2 expression?

FOXP2 is expressed in similar and partly overlapping regions in all vertebrates studied, mainly in cerebellar and basal ganglia circuits. Regions include the lateral ganglionic eminence in the developing brain which gives rise to the striatal medium spiny projection neurons, involved in planning and modulation of movement; thalamus, in particular the regions that receive input from the basal ganglia; the inferior olives, which are part of the cerebellar motor learning and function; cerebellar Purkinje cells and deep cerebellar nuclei as well as sensory auditory midbrain structures. These regions implicate FOXP2 in the fine sensorimotor coordination/integration which underlies the sequenced behavior and learning behind speech and language.

FOXP2 is not expressed in the structures that form the trigeminal sensorimotor circuit that controls orofacial movements. So FOXP2 apparently has nothing to do with the control of the movements of the mouth and lower face, but rather with the coordination, planning and learning of these movements.

6. How is the human FOXP2 gene different from that of our closest extant relative the chimpanzee? What consequence does this have for the human FOXP2 protein function?

The human FOXP2 gene has two characteristic amino acid substitutions in exon 7 compared to the chimpanzee gene - a threonine to asparagine substitution in position 303 and an asparagine to serine substitution on position 325. The latter substitution leads to a hypothetical target site for protein kinase C and a minor structural change. Phosphorylation of transcription factors is an important way of regulating gene expression. Even this small difference between humans and chimpanzees could lead to a dramatic change in the regulations of the variety of genes that are under the control of FOXP2.

7. Has the human FOXP2 gene been under any selective pressure? How can we see this?

It seems as though the human FOXP2 gene has been under recent positive selection rather than relaxed negative selection. This means that whatever changes the human-specific mutations caused, they gave significant benefits to the individuals that carried them. This could be seen by studying the FOXP2 gene sequences in mouse, great apes and human and comparing non-synonymous substitutions, mutations that change the amino-acid sequence of the protein, with synonymous substitutions, mutations that don't.

8. The Neanderthal FOXP2 gene seems to be identical to that of modern humans. With other primates in mind, what consequences does this have for the expansion of modern humans?

This is a very big and very open discussion that in the end is more speculative than anything, albeit based on actual scientific findings. The question seems to be whether or not the emergence of a complex language lead to our cultural and therefore geographical and demographical expansion? It's definitely tempting to draw the conclusion that we became so successful because we evolved a language that allowed us to cooperate between individuals like never before. The human-specific mutations in FOXP2 may very well have been a pivotal point in this development. If Neanderthals had the same FOXP2 sequence as us modern humans, it's probable that they possessed many of the same faculties of language and culture that we do. Maybe at one time in history we understood each other?

9. In what way is FOXP2 special in echolocating bats? Can this provide any clues with regards to FOXP2 function? Can this be contrasted to FOXP2 in echolocating whales?

FOXP2 has diverged more in echolocating bats than any other group of vertebrates. This further implicates FOXP2 in sensorimotor coordination and vocal learning, which are requirements for echolocation. The same pattern could not be seen for echolocating whales, presumably because their echolocation is mediated through their foreheads and would not require sensorimotor coordination of their mouth and face.

10. Using what you have learned about FOXP2 in humans, birds, bats, whales and other animals, what can you say about the evolution of vocal communication and language? Is language a uniquely human feature?

This is yet another very big and very open discussion. Arguably, many animals possess some of the faculties of our speech and language. Most animals vocalize, for instance, even though it's only growls, barks, meows, shrieks, squeaks et.c. As we've seen, some learn their complex vocalization patters by mimicking adults, just like we do, and some even have more complex systems where different sounds are connected to different meanings. A few species of monkeys can distinguish between different predators and warn their fellow group-members accordingly.

But is this language then?

I would say no. The best definition I know of language is "the ability to produce infinite meaning from a finite sent of sounds or symbols", and this is clearly a human-specific feature, as far as our best knowledge goes. With our language we are able to describe not only that which we can sense, but also a wide spenctrum of things we cannot sense at all! Even things that are completely invented. We use language not only for utility but also creatively to make things up. We can even make up words that have no meaning attached to them.

Still, the fact that other animals possess some faculties of speech is significant because it firmly bases our unique adaptation of language and culture within natural processes by showing that a stage was already set from which a few genomic events could lead to our advanced use of vocalization.

Swedish blog tags: Vetenskap, Biologi, Neurovetenskap, Språk
Technorati tags: Science, Biology, Neuroscience, Language, FOXP2

Scharff, C., Haesler, S. (2005). An evolutionary perspective on FoxP2: strictly for the birds?. Current Opinion in Neurobiology, 15(6), 694-703. DOI: 10.1016/j.conb.2005.10.004

Enard, W., Przeworski, M., Fisher, S.E., Lai, C.S., Wiebe, V., Kitano, T., Monaco, A.P., Pääbo, S. (2002). Molecular evolution of FOXP2, a gene involved in speech and language. Nature, 418(6900), 869-872. DOI: 10.1038/nature01025

Krause, J., Lalueza-Fox, C., Orlando, L., Enard, W., Green, R., Burbano, H., Hublin, J., Hänni, C., Fortea, J., de la Rasilla, M., Bertranpetit, J., Rosas, A., Pääbo, S. (2007). The Derived FOXP2 Variant of Modern Humans Was Shared with Neandertals. Current Biology, 17(21), 1908-1912. DOI: 10.1016/j.cub.2007.10.008

Li, G., Wang, J., Rossiter, S.J., Jones, G., Zhang, S., Ellegren, H. (2007). Accelerated FoxP2 Evolution in Echolocating Bats. PLoS ONE, 2(9), e900. DOI: 10.1371/journal.pone.0000900

Fisher, S.E., Vargha-Khadem, F., Watkins, K.E., Monaco, A.P., Pembrey, M.E. (1998). Localisation of a gene implicated in a severe speech and language disorder. Nature Genetics, 18(2), 168-170. DOI: 10.1038/ng0298-168

Lai, C.S., Fisher, S.E., Hurst, J.A., Vargha-Khadem, F., Monaco, A.P. (2001). . Nature, 413(6855), 519-523. DOI: 10.1038/35097076

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Brief report

The last few weeks have been a bit hectic. Aside from trying my best to keep up with my research, I've taken the mandatory research ethics and philosophy of science graduate course as well as prepared and carried out an electrophysiology computer lab and a literature seminar for the neurobiology undergraduate course (which was great fun). I've also gotten some reading done, not only on new exciting articles, but also on Evolution by Douglas Futuyma, which we're analyzing as a sort of literature course in my department. So I've been busy, busy, busy which isn't really a problem 'cause I like it that way. But it means that the rest of my retort to the creationist lecture will have to wait until I find some time to finish it. Most of it is done but I don't want to break it down even more than it is.

What makes things a bit difficult is that I seem to have contracted a rather bothersome ear infection in my right ear. Fortunately it hasn't managed to keep me in bed all day (only when the ache and the fever and the swollen throbbing lymph-nodes were too tiresome to handle) and I am feeling much better now, even though my ear and throat still hurt.

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Retort to a creationist lecture pt. 2

This is the second post in a series examining the lecture given by creationist author Anders Gärdeborn this past Thursday at Uppsala Universitet, by invitation from evangelical christian student organization Credo.

Now, with the introduction out of the way, I will continue by examining what Gärdeborn presented as, in his view, solid scientific arguments against evolution. I have, as far as possible, tried to formulate my text without giving Gärdeborn too much credit for them as these are in no way new arguments, nor are they his. They have been for a long time, and they continue to be, part of the general creationist discourse.

For the sake of order, I have grouped them roughly under the headings "the structured universe", "the 'devolution' of nature", "evolution 'within kinds'" and "biological information". I had planned on examining all four of them in one post, but since I want to be quite meticulous and I'm busy working on a shorter print version of this essay in Swedish, I'm choosing to publish the first two in advance.

The structured universe

The first supposedly scientific argument is hilariously outdated. Gärdeborn formulated it something like - "the universe is finely calibrated and full of complex structure, ergo it has to have an intelligent designer behind it!" We know that this is nothing but the old fallacious argument from incredulity, but it's worth examining it a bit further with regard to this apparent "structure" he was talking about. The word "structure" in this case being used instead of the one chiefly used by creationists - design. "If there is a design, there must be a designer!"

This cognitive fallacy can be beautifully illustrated by the well-known and often quoted anecdote involving philosopher Ludwig Wittgenstein:

W. and his companion are on a stroll through Cambridge.

"Tell me", says W., "why do people always say it was natural for man to assume that the Sun went round the Earth rather than that the Earth was rotating [around the sun]?"

"Why?" said his surprised interlocutor, "well, obviously, because it just looks as though the Sun is going round the Earth."

"Hmm", retorted W., "well, what would it have looked like if it had looked as though the Earth was rotating [around the sun]?"

In our particular situation Wittgenstein might just as well have asked, "what would the universe have looked like if it had looked as though it had no structure?" The answer is the same: it would have looked no different.

Some logical fallacies are errors of perspective. The way something appears to us can be regarded as a property of that something we are observing; we automatically assume this in practically everything we do. But this property, the way it appears, is also interesting in itself because it reflects an implicit property of that to which it appears, us. In other words we might say that the universe looks as though it's organized and structured simply because we are looking for organization and structure in the universe. It's the method our brains use to describe our surroundings to us in a way that we can find useful. The fact that we have a penchant for observing structures and patterns in the biological world is a reflection of us, not it. It's a bias in our thinking which is also inevitably mirrored in our language. Even the most experienced and senior scientist might express wonder at the structure of that which he or she is studying, but a scientist realizes that this structure, this purposeful organization, is only apparent. Our brains and in extension our language and preferred choice of words might deceive and mislead us more than we usually are able to acknowledge.

I can only say that it's unfortunate that Gärdeborn did not read up a little more on the basics of cognitive neuroscience before embarrassing himself by falling into such an easily avoidable fault.

The "devolution" of nature

While still on the subject of structure, Gärdeborn misrepresents evolution as a linear process through which "things with structure develop from things with less structure." This is a totally unfounded oversimplification. Deviously, creationists only use it because it serves their purpose. It's a classical straw man - they misrepresent their opponent's position so that it's easier to refute. But as it turns out, even this misrepresentation is not an easy one to counter.

While evolutionary processes have indeed increased the complexity of organisms over evolutionary time, this is in no way an intrinsic property of evolution itself. In fact, evolution has decreased complexity many times. One of the most poignant examples being parasitic organisms, many of which have lost structures and functions in comparison with their free-living counterparts. The parasitic bacteria in the genus Mycoplasma, for example, have lost their external cell walls as well as most of their metabolic pathways as a part in their adaptation to the highly specialized conditions within their hosts. This is seen in their genomes; Mycoplasmas have some of the smallest ones observed in any organism.

At the core of this misleading definition of evolution is then a serious problem. In order to affirm that evolution goes from less structure (or lower complexity) to more structure (or higher complexity) you have to suppose that evolution has a predestined goal. But not only that; as a result of this false assumption you would have to suppose that organisms which exhibit less complexity are less evolved. Of course no biologist would ever suppose this, it's not only the greatest but also the most easily avoidable fallacy you can make in evolutionary thought, as any good high-school biology textbook will tell you. Yet this is what Gärdeborn proclaims evolutionary scientists do. What poor understanding.

The reason it's so common to ascribe goal and intention to evolutionary processes is simply that we have a hard time describing or understanding evolution in other terms. This is another way in which our language misleads us. Within the world of research, we all of course know what we really mean to say.

What is Gärdeborn getting at then? What purpose does this flawed definition of evolution serve? This is the old "second-law-of-thermodynamics-argument" against evolution, maybe the silliest and most simple-minded argument creationists have ever used. The argument owes its recent revival to mathematician and intelligent design proponent Granville Sewell who, in the beginning of the decade, published a couple of articles on the matter. Articles that have subsequently been panned by serious biologists, physicists and mathematicians alike.

The second law of thermodynamics states, in one of its simplified forms, that natural processes in a system only can lead to the increase in the entropy of the system. Entropy being a sort of measure of "disorder" or lack of complexity. "But wait a minute now! How can evolution then increase the complexity of living organisms!? Wouldn't that decrease the entropy?" Believe it or not, that is the entire argument. Since nobody doubts the veracity of the second law, it must be evolution that is false.

I've already established that evolution does not necessarily lead to organisms with higher complexity than their ancestors. But even if we assumed that it always does, the second law of thermodynamics is only valid for closed systems. Earth imports energy from the sun and thus contributes to the total entropy of the universe. In the same way, organisms import energy in order to sustain themselves, decreasing their own local entropy, but at the same time contribute to the increase in the total entropy of their surroundings. Neither earth nor living organisms are closed systems.

The way creationists usually respond to this fact is by invoking the argument from incredulity again, saying that the fact that organisms can import energy, and thus supposedly "break" the second law, is so unlikely that it simply must mirror an purposeful design. This in fact makes the "second-law-of-thermodynamics-argument" a non-argument. As comically ridiculous as it is, creationists are still using it.

Aside from the fact that it negatesitself, it's a particularly bad argument because it's merely a rhetorical one, not a scientific one. By appealing to our "common sense" and our own observations of nature, and not least to our cognitive bias towards structure and purposefulness, creationists try to win us over. "Surely", they'll say, "you must notice that in nature everything has a tendency to break down, not to be built up, as evolutionists tell you. Nature devolves, it doesn't evolve." It's devious, it's misguided and it's not science. The second law is not about probabilities or common sense, it's about thermodynamics and entropy. Creationists can either produce an entropy calculation showing that evolution breaks the second law, which is impossible, or they can shut up. That's my modest advice.

Edited February 21. Thanks to SK for pointing out an error.

Swedish blog tags: Vetenskap, Evolution, Biologi, Pseudovetenskap, Kreationism
Technorati tags: Science, Evolution, Biology, Pseudoscience, Creationism, BPSDB

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