Category: Siddharta Mukherjee

It isn’t creativity that fades, but stamina: science is an endurance sport

Gene, protein, function, and fate were strung in a chain: one chemical alteration in one base pair in DNA was sufficient to “encode” a radical change in human fate.

Phenotype, in short, drags genotypes behind it, like a cart pulling a horse. It is the perennial conundrum of natural selection that it seeks one thing (fitness) and accidentally finds another (genes that produce fitness). Genes that produce fitness become gradually over-represented in populations through the selection phenotypes, thereby allowing organisms to become more and more adapted to their environments. There is no such thing as perfection, only the relentless, thirsty matching of an organism to its environment. That is the engine that drives evolution.

This was the missing link in Darwin’s Logic: reproductive incompatibility, ultimately derived from genetic incompatibility, drove the origin of novel species.

Muller was catapulted into the international fame by his discovery. The effect of radiation on the mutation rate in flies had two immediate implications. First, genes had to be made of matter. Radiation, after all, is merely energy. Frederick Griffith had made genes move between organisms. Muller had altered genes using energy. A gene, whatever it was, was capable of motion, transmission, and of energy-induced change properties generally associated with chemical matter.

When power is discovered, man always turns to it,” Bateson wrote darkly. “The science of heredity will soon provide power on stupendous scale; and in some country, at some time not, perhaps, far distant, that power will be applied to control the composition of a nation. Whether the institution of such control will ultimately be good or bad for that nation, or humanity at large, is a separate question.” He had preempted the century of the gene.

As the geneticist J.B.S. Haldane had described it in 1923, once the power to control genes had been harnessed, “no beliefs, no values, no institutions are safe.

The rediscovery of Mendel’s laws of heredity in the opening weeks of the 20th century sparked a scientific quest to understand the nature and content of genetic information that has propelled biology for the last hundred years. The scientific progress made [since that time] falls naturally into four main phases, corresponding roughly to the four quarters of the century.””The first established the cellular basis of heredity: the chromosomes. The second defined the molecular basis of heredity: the DNA double helix. The third unlocked the informational basis of heredity [i.e. the genetic code], with the discovery of the biological mechanism by which cells read the information contained in genes, and with the invention of the recombinant DNA technologies of cloning and sequencing by which scientists can do the same.” The sequence of the human genome, the project asserted, marked the starting point of the “fourth phase” of genetics. This was the era of “genomics” – the assessment of the entire genomes of organisms, including humans. There is an old conundrum in philosophy that asks if an intelligent machine can ever decipher its own instruction manual. For humans, the manual was now complete. Deciphering it, reading it, and understanding it would be quite another matter.

Some may smile and may feel that this is but a new version of the old dream of the perfection of man. It is that, but it is something more. The old dreams of the cultural perfections of man were always sharply constrained by his inherent, inherited imperfections and limitations… We now glimpse another route – the chance to ease and consciously perfect beyond our present vision this remarkable product of two billion years of evolution.