The Red Queen Rule, Eurypterids, and Forecasts for 2008

Where Crayfish Winter
One of the greatest challenges in studying biological evolution is the absence of a time machine. What we commonly regard as evolution — speciation, the emergence of new groups — proceeds extremely slowly. Without knowing how and what to observe, a long human lifetime may not suffice to record any changes whatsoever.
A team of biologists, led principally by Belgian scientists, published a brief article (a "letter") in Nature describing the results of a remarkably elegant experiment "studying" evolution. These biologists figured out where and how to look!
The article described the evolution of Daphnia (the widely known cladoceran crustaceans) and the bacteria Pasteuria ramosa that parasitize them. Upon infecting Daphnia, these microparasites do not kill their hosts but reduce their fecundity. Therefore, in the course of evolution, Daphnia ought to become progressively less susceptible to the bacteria. On the other hand, the bacteria must evolve to enhance their capacity to infect Daphnia — otherwise they would simply disappear! These considerations should drive an endless "arms race" between parasite and host. But how can it be studied? In our high-technology era, the first approach that comes to mind for well-equipped American scientists is to extract DNA sequences from contemporary material and archival samples, read them, and compare them against one another. The principal difficulty with such work is the complexity of interpreting genetic texts. Who can determine why they change? The experimenters found a more ingenious approach: they assessed the fitness of parasites and hosts directly, by pitting them against each other.
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Both Daphnia and their parasitic bacteria are capable of forming dormant stages. Each autumn, dormant eggs of Daphnia and bacterial spores sink to the bottom of the water body. In spring, some are activated while others remain in the bottom sediments. In the study described, the authors extracted a sediment core from silt that had accumulated over thirty years in a small Belgian pond. They divided the thirty-year period into eight layers, each corresponding to several (two to four) years. From each layer, Daphnia eggs and bacterial spores were isolated and revived. Daphnia from each time period were multiplied to the required numbers, and each group was then challenged with bacterial strains from each time period. The efficiency of parasitism was assessed by the proportion of infected Daphnia.
As expected, the greatest danger to Daphnia came from their contemporary parasites. Bacteria from earlier and later sediment layers overcame the crustaceans' defenses with considerably lower efficiency. Incidentally, viewed from outside, the Daphnia-bacteria system might appear to be in a stable state, since at any given moment the pathogenicity of the parasite toward its host remains approximately constant. The authors interpret this as confirmation of the well-known "Red Queen Rule," proposed by the palaeontologist Leigh Van Valen. The essence of this rule can be conveyed by a simple argument (the overwhelming majority of evolutionary changes in any species are associated with adaptation to a changing environment), or by a quotation from Lewis Carroll's immortal text: "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!"
And so the Daphnia and the bacteria "run," leaving in the sediment layer the traces of their unceasing race...

And Crayfish, and Scorpion
Why do people listen open-mouthed to stories of freaks and monsters that inhabited the Earth in prehistoric times? For no particular reason — it is simply interesting, and that is all there is to it! Storytellers can now add a new creature to their bestiary, one that is being reported with evident relish by numerous media outlets.
A previously unknown species of eurypterid — Jaekelopterus rhenaniae — has been discovered in Germany. The specimen is dated to 390–400 million years ago, placing it in the Early Devonian. It belongs to the class Merostomata, which today includes only a few extant species of horseshoe crabs. Eurypterids were predatory, bottom-dwelling animals. Their chelicerae (head appendages) were armed with spines or claws, and the posterior abdomen bore a spine or a swimming paddle. They inhabited both marine and freshwater environments, and occasionally even ventured onto land. In Scotland, for example, the trackway of a one-and-a-half-metre eurypterid from the Carboniferous period was recently discovered, showing it had crawled some distance along the shore.
The new specimen is incomplete, but includes a claw 46 centimetres in length. By analysing the proportions between body size and claw dimensions in eurypterids of this group, British palaeontologists concluded that Jaekelopterus reached 2.5 metres in length and weighed approximately 200 kg. In the freshwater environments of the Early Devonian, such a monster would have had no rivals — unless the remains of even larger relatives lie somewhere undiscovered. That said, given the constraints that an exoskeleton imposes on the body size of arthropods, it is clear that the dimensions of this specimen approach the upper limit.
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This discovery allows us once again to appreciate how intense was the struggle for dominance in ecosystems through which our own evolutionary lineage passed. What marks the success of a given animal group? Species diversity? By that measure, the winners of the "great game" are the insects, along with other classes of the phylum Arthropoda — the most species-rich group of living organisms on our planet. Complexity of behaviour and perfection of organisation? Here the leaders are we, the vertebrates (subphylum of phylum Chordata), and the representatives of the class Cephalopoda. Geographic range? Arthropods and vertebrates are dominant, while cephalopods are at a disadvantage.
The history of the Palaeozoic Era preserves the record of an intense contest for dominance among all three "peaks" of animal evolution — cephalopods, arthropods, and vertebrates.
In the course of this struggle, terrifying creatures arose. For a time, supremacy was held by many-metre cephalopod molluscs with straight, gas-filled shells. The gas enabled them to hover in the water column, a jet-propulsion system allowed them to target prey, muscular tentacles served for seizing victims, and a powerful horny beak could crush any armour. Yet the giant molluscs lost. For a long period, the apex predators in the water were the armoured eurypterids. But already in the time of Jaekelopterus, sufficiently large fishes had become widespread in the seas. They excelled primarily in speed of movement. A flexible body, an internal skeleton, jaws with teeth, and complex behaviour made fishes and their descendants — the tetrapods — the ultimate victors of the evolutionary arms race, both in the sea and on land. Yes, Jaekelopterus was formidable. But "we" won!

Past and Future. There Will Be No Revolutions. There Will Be No Boredom Either
Another arbitrary boundary... How quickly they pass: no sooner had I grown accustomed to writing "2007" in dates — rather than, say, "2002" or "2005" — than I must now accustom myself to "2008"! The years have grown rather short-lived...
What will the departing year be remembered for? I do not yet know. But from my current vantage point, I shall name a couple of circumstances relating to biology, and one from the sphere of public life.
PAST-1
The epigenetic theory of evolution has been noticed! And criticism has begun! I was never satisfied by the explanation of life's perfection around us that is conventionally offered in school: "Every organism develops according to its own programme; certain errors in these programmes lead to improvements in organisms; over time, such errors displace their original versions." I do not believe it! In time, my disbelief was cast into a relatively academic form, but its substance remained unchanged. Back in the early 1990s, I was conversing with one of Russia's most competent evolutionists and said to him that a genius was needed to resolve this problem. He replied: "A genius? One floor up, turn right past the toilet — that is his office!" And he even gave me one of the books in which Mikhail Alexandrovich Shishkin expounded the "epigenetic theory of evolution of Schmalhausen and Waddington."
Having become acquainted with Shishkin in 1999, I tried to obtain from him an answer to why the theory, published in 1987–88, was known to nobody. And what was he doing to make himself understood? Why was he not fighting for recognition? At that time I knew only a few other people who had heard of the ETE (epigenetic theory of evolution) and were able to understand it. I had grown accustomed to being an advocate of what were practically esoteric views on evolutionary theory. The situation changed, it seems to me, precisely in 2007. The theory was heard of — and criticism began! At an evolutionary conference held at the end of the current year in Moscow, several people even criticised it (mostly, in my view, from misunderstanding). In any case, this is an important development. Perhaps one may yet live to see constructive criticism and recognition of the principal ideas of the ETE?
PAST-2
The danger of GMOs? At last there is something to discuss! For several years I have been interested in the "greens'" campaign against genetically modified organisms (GMOs). It began when one of the figures in the conservation movement gave me to read the "bible" of Russian anti-GMO campaigners — a book entitled "Kings and Cabbage" (forgive them, O. Henry, for they know not what they do). I was astonished.
In my assessment, the book was saturated with logical fallacies, errors, distortions, deception, and public scaremongering. How could competent and principled people support a campaign conducted by such means? I wrote an open letter to A. V. Yablokov, the eminent biologist who had provided funding for this book, and circulated it among conservation organisations. The responses I then received sharply worsened my opinion of the "greens." The majority of my correspondents were, of course, interested in knowing where my thirty pieces of silver came from — but some did address the substance of my arguments. One reply contained approximately the following sentiment: "Ethics, honesty? Leave that chatter for American housewives. You see that the arguments intended to stop GMOs are weak? Then think of a way to strengthen them!"
At the end of the current year I wrote a response for "KT" to a reader's letter about GMOs. In searching for support for my position, I found that the discussion of the possible harms of GMOs had finally shifted toward considering the results of more or less coherently described experiments. If these reports are accurate and correctly interpreted, this may mean that adverse effects of certain (specific!) categories of GMOs have been registered. There are now grounds for considering that if active vectors (structures that facilitate the transfer of information) are retained in modified organisms, they may become a dangerous mutagenic factor. Naturally, these findings do not apply to GMOs produced using technologies that leave no hazardous vectors.
On the other hand, I cannot rid myself of the suspicion that someone who regards honesty as the province of American housewives has devised a way to cause the greatest harm to the hated technology and has succeeded in artfully fabricating the evidence.
What now? Verification. Research. Precaution. Opponents of GMOs will endeavour to bury the technology as a whole. What is needed is not outcry but the most rapid possible organisation of rigorous studies of the described effect. Does it genuinely exist? How dangerous is it? Which genetically modified organisms are safe from this perspective? How must the genetic modification procedure be changed? What methods of investigation of new products should be required before their introduction into widespread use? Alas, in resolving these problems, the waves of fear generated by "green" propaganda are an obstacle rather than an aid.
PAST-3
To play by others' rules while preserving one's integrity? An illusion! In the departing year I have become definitively disillusioned with games played by others' rules. Let me pose a general question: do you think one should play the assigned role in a spectacle where the declared aims serve only to mask the true interests of the scriptwriters? Even if your answer is "no," you may find yourself, as I did this year, drawn again and again into such games.
This New Year is notable for the fact that both Ukraine and Russia have passed through one set of elections and are heading toward another. No, I am not opposed to participation in elections. I have voted and shall probably continue to do so. But I shall try not to forget that this is their game. I shall simply try to choose those cup-and-ball operators who appear not to carry baseball bats...
I once formulated for myself that there are four spheres of activity not linked to serving false gods: science, medicine, education, and art. Alas, even in these spheres one can trade one's conscience and soul... And the social structures that seek to use us are least of all interested in our integrity.
How fortunate it is that the New Year is not a state or ideological but a popular, family celebration!
And what comes after it? Predicting the future is even harder than drawing up the balance of the past. And yet... Well, for example, when the Human Genome Programme was just beginning, did I not know that the complete sequencing of the genome would not mean its comprehension? Not only the mass media but even some biologists believed: now, at last, we shall read the "code of life," understand it, and then alter it as we wish... It was read. A mass of useful specific facts was discovered, and we were once again reminded of how far we are from understanding the whole.
Well then, I shall venture two or three predictions.
FUTURE-1
There will be no revolutions — there will be a long road with diverse "bonuses" along the way. How attractive, for instance, did the prospects of cloning once appear? Since an organism is a realised genetic programme, replace the set of information and you obtain what you desire. If instead of a CorelDraw! installation disc you insert a genuine Adobe Illustrator disc, the one programme is replaced by another — is that not right? And so it would be with cloning: insert mammoth DNA in place of elephant DNA and you get a mammoth; insert the nucleus of your beloved cat's cell into the egg cell of an ordinary cat — and there she is, your darling's second life! That would hold if organisms had hardware and software in the way modern computers do. In organisms, there is no external programme; any programme is part of the cell itself. In biological terms, the genotype is part of the phenotype. Yes, by altering this part we can register changes in other parts — but the same applies to any other component of the integral organism! Thus it turns out that in cloning it is not enough to "transfer" the genetic programme — one must reconfigure the entire integral system. And here, each successive discovery advances researchers one step and confronts them with the next difficulty. Have you ever walked towards mountains on foot? It seems that they are only half an hour away and that the ascent will soon begin. One need only reach that bend in the road to see what lies beyond it. But beyond it lies another stretch of path. And the walk will take not half an hour but perhaps a day or two, or more...
So — are cloning studies pointless? They are not. But first one must understand how organismal development is regulated. Have you ever reflected that, in the typical case, a human being is a clone of a single cell? The dying cells of the hair, the transparent cells of the cornea, the enucleated erythrocytes, the fused muscle cells — all are clones of the zygote, the fertilised egg! And in passing through their developmental path, these cells can both specialise and de-specialise, reversing their development. As the complex of commands governing this process is elucidated, we shall become ever more proficient at controlling the development of cell lineages. In time, we may perhaps succeed in growing new organs to replace worn-out ones from clones of the patient's own cells.
FUTURE-2
We are in for a multitude of discoveries that challenge the foundations of genetics. This prediction is of a piece with the previous one. The excitement at having found simple rules explaining how an organism functions is already fading. Competent geneticists have long since ceased to attempt to decompose the organism into a sum of effects from individual genes. Yet inertia of thought is a formidable force! People remote from reflection on the mechanisms of developmental regulation will continue for a long time to repeat old stories, confident that they are expounding the latest paradigm of the science of heredity. I believe that, beyond the mechanisms of inheritance associated with the conformation (three-dimensional folding) of macromolecules, beyond the mechanisms of regulation of DNA activity and the editing of its text using diverse RNA species and proteins, the biology of the future will know other means of transmitting information across generations. Which means? Time will tell. When shall we learn of them? Not necessarily in 2008 — but perhaps even in 2008 something will reward our curiosity...
FUTURE-3
The rate of change in our environment will increase, and the Earth will become too small for an oversized humanity. Do you know what dynamic is characteristic of perturbations associated with resource exhaustion? Once, a graph depicting the desertification of pastures made a deep impression on me. The quantity of organic matter in the soil decreases smoothly, with slight acceleration, approaching a certain level. Reserves dwindle, but for a time this is not very noticeable. After the critical level is reached, however, the rate of change suddenly accelerates sharply and begins to slow only in the final stages — as it approaches zero. The same happens when an old building is demolished. At first, plaster falls from somewhere, a beam or frame drops here and there, but the structure remains recognisably itself. Then suddenly the supports give way, the floors collapse onto one another, and the construction becomes a heap of rubble. The further settling of that heap is a different and less dramatic story...
I cannot rid myself of the feeling that already in the coming year we shall observe an increase in the rate of change. Is this Cassandra's prophecy? Not necessarily. Of course, the crisis we are confronting contains little that is good. But it is not a death sentence. I have already written about this in "KT"... The fact that we are mortal does not deprive our lives of meaning. And humanity as such retains the chance to survive and to change. Moreover, those chances depend on our actions as well. Do you remember the classic parable of the man hanging by a blade of grass over an abyss, who reaches for a wild strawberry growing nearby — sweet, sweet?
It seems to me that one must somehow overcome the tragic sense of the possible changes in the world we inhabit, and try to put something right. I still want to believe that the world of my three children will give them the opportunity to live a full life. What must be done for this? Believe in the best. Prepare for change. Endeavour to understand how this world and the creatures inhabiting it are constituted. Hope...
But after 1 January 2008, the world will be renewed, will it not? To your health!

1 The route is approximate. Back to text

2 What is the meaning of the caveat about the "typical case"? The fact is that many of us are mosaics — composites of two or more genetically distinct cell clones (somewhat like conjoined twins fused into a single whole...). Back to text
D. Shabanov. Where Crayfish Winter // Computerra, Moscow, 2008. Issue 1-2 (717-718). P. 13 163
D. Shabanov. And Crayfish, and Scorpion // Computerra, Moscow, 2007. Issue 45 (713).
D. Shabanov. Past and Future. There Will Be No Revolutions. There Will Be No Boredom Either // KT, Moscow, 2007. Issue 47 (715).