Artificial life

21/05/2010

Predictions revisited

Forecasts and fears about artificial life

Today’s news of Craig Venter’s success in fashioning a new species of bacterium, with completely man-made DNA, propels me to the bookshelf to recall how this breathtaking event was anticipated with some trepidation.

“Fried-egg” colonies of (a) the synthetic bacterium Mycoplasma mycoides JCVI-syn1.0 and (b) the natural Mycoplasma capricolum bacterium that provided the cytoplasm but had its DNA replaced. The blue colour in (a) is created by a protein coded in the new DNA that reacts with a chemical in the agar base. Without that gene the colonies of the unmodified recipient bacterium remain white (b). From Gibson et al. Science, see references.

In brief, as reported online in Science magazine, Venter’s team designed, synthesized and assembled a DNA chromosome. They transplanted it into a bacterium to create novel cells controlled only by the synthetic DNA, and capable of continuous self-replication.

Anticipations of manipulated life

My personal favourite among the projections of genetic engineering has for long been that of the physicist Freeman J. Dyson, with his idea of breeding gigantic trees capable of living on comets, to provide human habitation even in the outer Solar System.

But if you google “genetic engineering” you’ll get 5.4 million offerings, or 2.2 million for “bioethics”. Old books on my shelf have many pages on the future manipulation of life and its possible risks. To be reasonably brief, I’ve picked a possibly useful overview of issues anticipated a quarter of a century ago. It’s from The Green Machines, which was written as if looking back from 2030 and published in 1986.

In Aztec times in Mexico, people made biscuits out of mats of cyanobacteria called Spirulina, which they harvested from alkaline lakes. By the 1970s Spirulina was known to be exceptionally rich in protein, and harvesting resumed in Mexico. Italian microbiologists discov­ered that they could prolong the growing season for Spirulina by cultivating it in polyethylene tubes, and they reported pro­duction rates of 50 tons per hectare per year-roughly ten times the yields of ordinary crops. Doing without sunshine, Imperial Chemical Industries grew bacteria (Methylophilus methylotrophus) on methanol and marketed them as Pruteen.

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