Dyson’s take on evolution

Freeman Dyson always has something interesting to say on most topics. In the March issue of Technology Review he summarizes Carl Woese’s idea about the end of Darwinian evolution due to bioengineering. I don’t think we’ve stopped evolving since we’re still battling microbes but the thought is intriguing and terrifying.

Carl Woese published a provocative and illuminating article, A New Biology for a New Century, in the June 2004 issue of Microbiology and Molecular Biology Reviews. His main theme is the obsolescence of reductionist biology as it has been practiced for the last hundred years, and the need for a new biology based on communities and ecosystems rather than on genes and molecules. He also raises another profoundly important question: when did Darwinian evolution begin? By Darwinian evolution he means evolution as Darwin himself understood it, based on the intense competition for survival among noninterbreeding species. He presents evidence that Darwinian evolution did not go back to the beginning of life. In early times, the process that he calls horizontal gene transfer, the sharing of genes between unrelated species, was prevalent. It becomes more prevalent the further back you go in time. Carl Woese is the worlds greatest expert in the field of microbial taxonomy. Whatever he writes, even in a speculative vein, is to be taken seriously.

Woese is postulating a golden age of pre-Darwinian life, during which horizontal gene transfer was universal and separate species did not exist. Life was then a community of cells of various kinds, sharing their genetic information so that clever chemical tricks and catalytic processes invented by one creature could be inherited by all of them. Evolution was a communal affair, the whole community advancing in metabolic and reproductive efficiency as the genes of the most efficient cells were shared. But then, one evil day, a cell resembling a primitive bacterium happened to find itself one jump ahead of its neighbors in efficiency. That cell separated itself from the community and refused to share. Its offspring became the first species. With its superior efficiency, it continued to prosper and to evolve separately. Some millions of years later, another cell separated itself from the community and became another species. And so it went on, until all life was divided into species.

The basic biochemical machinery of life evolved rapidly during the few hundred million years that preceded the Darwinian era and changed very little in the following two billion years of microbial evolution. Darwinian evolution is slow because individual species, once established, evolve very little. Darwinian evolution requires species to become extinct so that new species can replace them. Three innovations helped to speed up the pace of evolution in the later stages of the Darwinian era. The first was sex, which is a form of horizontal gene transfer within species. The second innovation was multicellular organization, which opened up a whole new world of form and function. The third was brains, which opened a new world of cordinated sensation and action, culminating in the evolution of eyes and hands. All through the Darwinian era, occasional mass extinctions helped to open opportunities for new evolutionary ventures.

Now, after some three billion years, the Darwinian era is over. The epoch of species competition came to an end about 10 thousand years ago when a single species, Homo sapiens, began to dominate and reorganize the biosphere. Since that time, cultural evolution has replaced biological evolution as the driving force of change. Cultural evolution is not Darwinian. Cultures spread by horizontal transfer of ideas more than by genetic inheritance. Cultural evolution is running a thousand times faster than Darwinian evolution, taking us into a new era of cultural interdependence that we call globalization. And now, in the last 30 years, Homo sapiens has revived the ancient pre-Darwinian practice of horizontal gene transfer, moving genes easily from microbes to plants and animals, blurring the boundaries between species. We are moving rapidly into the post-Darwinian era, when species will no longer exist, and the evolution of life will again be communal.

In the post-Darwinian era, biotechnology will be domesticated. There will be do-it-yourself kits for gardeners, who will use gene transfer to breed new varieties of roses and orchids. Also, biotech games for children, played with real eggs and seeds rather than with images on a screen. Genetic engineering, once it gets into the hands of the general public, will give us an explosion of biodiversity. Designing genomes will be a new art form, as creative as painting or sculpture. Few of the new creations will be masterpieces, but all will bring joy to their creators and diversity to our fauna and flora


3 thoughts on “Dyson’s take on evolution

  1. I think that “the obsolescence of reductionist biology as it has been practiced for the last hundred years, and the need for a new biology based on communities and ecosystems rather than on genes and molecules” is an interesting starting point. Indeed gene reductionism was a stepbackward from darwinism and a return to Lamarck’s kind of ideas. In the same vein “sociobiology” failed many years ago to produce a whole framework to understand cultures via the genome. Unfortunately M. Dyson’s comment on Woese’s ideas are typical of “when theory fails it is not because i failed to apply it correctly but merely because of virtual flaw of the theory”. It is the same attitude when my pupils cannot produce computer code that works and ask me to change the CPU !In order to this properly, you first need to change the truth :”By Darwinian evolution he means evolution as Darwin himself understood it, based on the intense competition for survival among noninterbreeding species.”That’s not what darwin wrote. he spend the first two chapters (of The origin of species ) explaining that there is no species or rather that species are named after an arbitrary line is drawn between two variations. “Evolution was a communal affair” means in other words things are coevolving. That’s correct and these are Darwin’s words as well. “Darwinian evolution requires species to become extinct so that new species can replace them.” A careful look at virtually ANY books of S.J. Gould should demonstrate that is not true and not in Darwin’s work. There are some more that need not to be quotedAlas this is not the end … Having found a so-called flaw in the theory the new idea (horizontal sharing of stuff) one needs to generalize to completely different things… ideas. Engels always said that in order to understand the world you need to cut it into pieces and start by studying each piece separately. But ultimately you need to reconstruct the puzzle. If not, your piece is the one that will explain everything and presumably will explain nothing. It ends with mixing “ideas” (things that still need to be defined) with “genes” (that is still need to be defined also). That ties the knot, young skywalker.Indeed in the process the author returns exactly at the same point against the flawed theories he wanted to fight. An inevitability of progress, a iconized vision of homo sapiens domination and a … gene reductionnism (somewhat generalized) I think that it is terrifying indeed: “Genetic engineering, once it gets into the hands of the general public, will give us an explosion of biodiversity” “We are moving rapidly into the post-Darwinian era, when species will no longer exist, and the evolution of life will again be communal.” It means that some scientist of importance are trying to moderate the acutal importance of the destruction of biodiversity and of our ecosystem. The domination of homo sapiens and the rise of bio-ingeenering means the end of biodiversity — exactly the opposite !that ends my (rather long) comment ./ed


  2. http://www.nytimes.com/2005/03/14/opinion/14leroi.html?pagewanted=all&position=A Family Tree in Every GeneBy ARMAND MARIE LEROI London — Shortly after last year’s tsunami devastated the lands on the Indian Ocean, The Times of India ran an article with this headline: “Tsunami May Have Rendered Threatened Tribes Extinct.” The tribes in question were the Onge, Jarawa, Great Andamanese and Sentinelese – all living on the Andaman Islands – and they numbered some 400 people in all. The article, noting that several of the archipelago’s islands were low-lying, in the direct path of the wave, and that casualties were expected to be high, said, “Some beads may have just gone missing from the Emerald Necklace of India.” The metaphor is as colorful as it is well intentioned. But what exactly does it mean? After all, in a catastrophe that cost more than 150,000 lives, why should the survival of a few hundred tribal people have any special claim on our attention? There are several possible answers to this question. The people of the Andamans have a unique way of life. True, their material culture does not extend beyond a few simple tools, and their visual art is confined to a few geometrical motifs, but they are hunter-gatherers and so a rarity in the modern world. Linguists, too, find them interesting since they collectively speak three languages seemingly unrelated to any others. But the Times of India took a slightly different tack. These tribes are special, it said, because they are of “Negrito racial stocks” that are “remnants of the oldest human populations of Asia and Australia.” It’s an old-fashioned, even Victorian, sentiment. Who speaks of “racial stocks” anymore? After all, to do so would be to speak of something that many scientists and scholars say does not exist. If modern anthropologists mention the concept of race, it is invariably only to warn against and dismiss it. Likewise many geneticists. “Race is social concept, not a scientific one,” according to Dr. Craig Venter – and he should know, since he was first to sequence the human genome. The idea that human races are only social constructs has been the consensus for at least 30 years. But now, perhaps, that is about to change. Last fall, the prestigious journal Nature Genetics devoted a large supplement to the question of whether human races exist and, if so, what they mean. The journal did this in part because various American health agencies are making race an important part of their policies to best protect the public – often over the protests of scientists. In the supplement, some two dozen geneticists offered their views. Beneath the jargon, cautious phrases and academic courtesies, one thing was clear: the consensus about social constructs was unraveling. Some even argued that, looked at the right way, genetic data show that races clearly do exist. The dominance of the social construct theory can be traced to a 1972 article by Dr. Richard Lewontin, a Harvard geneticist, who wrote that most human genetic variation can be found within any given “race.” If one looked at genes rather than faces, he claimed, the difference between an African and a European would be scarcely greater than the difference between any two Europeans. A few years later he wrote that the continued popularity of race as an idea was an “indication of the power of socioeconomically based ideology over the supposed objectivity of knowledge.” Most scientists are thoughtful, liberal-minded and socially aware people. It was just what they wanted to hear. Three decades later, it seems that Dr. Lewontin’s facts were correct, and have been abundantly confirmed by ever better techniques of detecting genetic variety. His reasoning, however, was wrong. His error was an elementary one, but such was the appeal of his argument that it was only a couple of years ago that a Cambridge University statistician, A. W. F. Edwards, put his finger on it. The error is easily illustrated. If one were asked to judge the ancestry of 100 New Yorkers, one could look at the color of their skin. That would do much to single out the Europeans, but little to distinguish the Senegalese from the Solomon Islanders. The same is true for any other feature of our bodies. The shapes of our eyes, noses and skulls; the color of our eyes and our hair; the heaviness, height and hairiness of our bodies are all, individually, poor guides to ancestry. But this is not true when the features are taken together. Certain skin colors tend to go with certain kinds of eyes, noses, skulls and bodies. When we glance at a stranger’s face we use those associations to infer what continent, or even what country, he or his ancestors came from – and we usually get it right. To put it more abstractly, human physical variation is correlated; and correlations contain information….Anne


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