Keywords: evolution; Darwin; Freeman Dyson; Carl Woese; species; bacteria; transfer of genes; biotechnology; photosynthesis; Green technology; M. S. Swaminathan.
Why is evolution such a hot topic more then 200 years after Darwin’s death? Ironically, Darwinian evolution may be in its last phase, soon to be replaced by a different kind of species change. At least, that’s what Freeman Dyson (see photo) suggests, and his judgment is remarkably astute.
Dyson’s article is brilliant. Its title as the same as the one above, except that I’ve added a question mark, for I’m a bit less optimistic on the subject than he. “Our Biotech Future” is in the July 19th issue of the New York Review of Books, and it takes off into some fanciful speculations arising from discoveries by the biologist Carl Woese.
Woese has added a third branch to the tree of life. It was formerly believed that there were only two: prokaryotes, which consisted of cells that lacked nucleui and eukaryotes, which had nuclei. Animals and plants are made from eukaryotes, whereas prokaryotes contained only microbes. Woese, however, discovered that there are two quite different types of prokaryotes, which he called bacteria and archea. The archea were initially believed rare, existing only in extreme environments such as hot springs, but now they are recognized as abundant everywhere on the planet.
Woese’s theory, as published as “A New Biology for a New Century,” in Microbiology and Molecular Biology Reviews, June 2004. This theory portrays these three branches of cells as having arisen sequentially from an even earlier type, among which genes could be transferred and separate species did not yet exist. As Dyson describes the situation:
“Life was then a community of cells of various kinds, sharing their genetic infoormation 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. Evolution could be rapid...”
From this communal soup, one day a primitive bacterium emerged, possessing an advantageous gene that it did not share with the community. Dyson writes:
“Its offspring became the first species of bacteria — and the first species of any kind — reserving their intellectual property for their own private use. With their superior efficiency, the bacteria continued to prosper and to evolve separately, while the rest of the community continued its communcal life. Some millions of years later, another cell separated itself from the community and became the ancestor of the archea. Some time after that, a third cell separated itself and became the ancestor of the eukaryotes. And so it went on, until nothing was left of the community and all life was divided into species. The Darwinian interlude had begun.”
If Dyson calls our period an “interlude”of two or three billion years, it is because he expects it to end shortly. Whereas genes could be transferred only reproductively from one generation to the next within particular species, we are already able today to do again with technology what the primordial “communities” of cells did long ago: transfer genes “horizontally” from one individual to another.
It is the promise of this new biotechnology that Dyson celebrates. Darwinian evolution – the competition for survival of noninterbreeding species — was necessarily slow, for, once established, species evolved very little. Ordinarily, one species must become extinct so that new species can replace them. Indeed, after homo sapiens arrived on the scene, biological evolution was so slow that cultural evolution— the transmission of ideas — accounted for comparatively much more than it did.
But in the future, species will change radically and rapidly. Dyson predicts that “green” biotechnology is about to overtake the “gray” sciences based on physics and chemistry — including computer technology. He predicts that the future will involve both green and gray technology, but that during the next fifty years, the green side will become as widespread in society as computers have during the past fifty years. Children, he says, will learn to transfer genes from one organism to another, just as they have learned to operate computers — by playing games with them in their spare time.
The social impact he foresees as mostly benign, even as overcoming rural poverty. Villagers in developing countries will be able to find green biotech jobs in the countryside and no longer have to migrate to gray jobs in the cities. We will develop plants (perhaps with black leaves full of silocon) that can more efficiently harness the sun’s energy than do the chlorophyll leaves of today. Dyson goes on and on about other possibilities:
“Genetically engineered earthworms could extract common metals such as aluminum and titanium from clay, and genetically engineered seaweed could extract magnesium or gold from seawater. Green technology could also achieve more extensive recycling of waste products and worn-out machines...”
Like Dyson, I am enthusiastic in believing that most of the solutions to humankind’s present problems will come from technological innovations. Contrary to many people, I believe that there are “technological fixes.” However, I am also aware that biotechnology presents great dangers.
There is one passage in Dyson’s article that sticks out like a sore thumb where he addresses (but only in a cursory way) the dangers of biotechnology. I think a harsh reviewer of the article must have read his light-hearted references to gene transfer as a child's game and insisted that he insert this passage, for it does not fit the euphoric tone of the rest. Here he writes, “Rules and regulations will be needed to make sure that our kids do not endanger themselves and others. The dangers of biotechnology are real and serious.”
Yet the elaboration of particular rules does not interest Dyson, beyond his naming of the problems. He excuses himself in this way: “I do not attempt to answer these questions here. I leave it to our children and grandchildren to supply the answers.”
I hope they can. Yet perhaps Dyson’s optimism actually does reflect wisdom. “ Sufficient to the day is the evil thereof.” (Matthew 6:34). We need not borrow problems from tomorrow, but should address those of today. Yet, there is a need for foresight too, and when it comes to the transfer of genes, I believe in the policy that M.S. Swaminathan expressed to me in an interview for the current (July) issue of Peace Magazine: “Hasten slowly.”
Don’t give your kid a genetic modification toy just yet. We have some issues to work out first.