Oswald Avery Quotes

The fundamental biological variant is DNA. That is why Mendel's definition of the gene as the unvarying bearer of hereditary traits, its chemical identification by Avery (confirmed by Hershey), and the elucidation by Watson and Crick of the structural basis of its replicative invariance, are without any doubt the most important discoveries ever made in biology. To this must be added the theory of natural selection, whose certainty and full significance were established only by those later theories.

If the results of the present study on the chemical nature of the transforming principle are confirmed, then nucleic acids must be regarded as possessing biological specificity the chemical basis of which is as yet undetermined.

Although the nucleus might have been recognized by Antonie van Leeuwenhoek in the late 17th century, it was not until 1831 that it was reported as a specific structure in orchid epidermal cells by a Scottish botanist, Robert Brown (better known for recognizing ‘Brownian movement’ of pollen grains in water). In 1879, Walther Flemming observed that the nucleus broke down into small fragments at cell division, followed by re-formation of the fragments called chromosomes to make new nuclei in the daughter cells. It was not until 1902 that Walter Sutton and Theodor Boveri independently linked chromosomes directly to mammalian inheritance. Thomas Morgan’s work with fruit flies (Drosophila) at the start of the 20th century showed specific characters positioned along the length of the chromosomes, followed by the realization by Oswald Avery in 1944 that the genetic material was DNA. Some nine years later, James Watson and Francis Crick showed the structure of DNA to be a double helix, for which they shared the Nobel Prize in 1962 with Maurice Wilkins, whose laboratory had provided the evidence that led to the discovery. Rosalind Franklin, whose X-ray diffraction images of DNA from the Wilkins lab had been the key to DNA structure, died of cancer aged 37 in 1958, and Nobel Prizes are not awarded posthumously. Watson and Crick published the classic double helix model in 1953. The final piece in the jigsaw of DNA structure was produced by Watson with the realization that the pairing of the nucleotide bases, adenine with thymine and guanine with cytosine, not only provided the rungs holding the twisting ladder of DNA together, but also provided a code for accurate replication and a template for protein assembly. Crick continued to study and elucidate the base pairing required for coding proteins, and this led to the fundamental ‘dogma’ that ‘DNA makes RNA and RNA makes protein’. The discovery of DNA structure marked an enormous advance in biology, probably the most significant since Darwin’s publication of On the Origin of Species .

Not long after his first meeting with Watson and Crick, Chargaff elected himself polemicist on behalf of all that has been left out—for the early discoverers, Friedrich Miescher and Oswald Avery; for the role of protein in the chromosome; for complexity and crowding in the cell; for humility and caution in the laboratory. “I am against the over-explanation of science, because I think it impedes the flow of scientific imagination and associations,” he said. “My main objection to molecular biology is that by its claim to be able to explain everything it actually hinders the free flow of scientific ideas. But there is not a scientist I have met who would share my opinion.

William Park, Oswald Avery, and Paul Lewis each approached science in his own way. Park, a man who almost became a medical missionary, saw it as a means to a larger end; he saw it as a tool to relieve suffering. Disciplined and methodical, his interest lay chiefly in immediate results that he could apply to his purpose. His contributions, particularly those made with Anna Williams, were enormous; their improvement of diphtheria antitoxin alone doubtless saved hundreds of thousands of lives over the past century. But his purpose also limited him, narrowed him, and limited the kind of findings he and those under him would make. Avery was driven and obsessive. Part artist and part hunter, he had vision, patience, and persistence. His artist’s eye let him see a landscape from a new perspective and in exquisite detail, the hunter in him told him when something, no matter how seemingly trivial, was out of place, and he wondered. The wonder moved him to the sacrifice of all else. He had no choice but to sacrifice. It was his nature. Cutting a Gordian knot gave him no satisfaction. He wanted to unfold and understand mysteries, not cut through them. So he tugged at a thread and kept tugging, untangling it, following where it led, until he unraveled an entire fabric. Then others wove a new fabric for a different world. T. S. Eliot said any new work of art alters slightly the existing order. Avery accomplished that all right, and far more. Paul Lewis was a romantic, and a lover. He wanted. He wanted more and loved more passionately than Park or Avery. But as is true of many romantics, it was the idea of the thing as much or more than the thing itself that he loved. He loved science, and he loved the laboratory. But it did not yield to him. The deepest secrets of the laboratory showed themselves to Lewis when he was guided by others, when others opened a crack for him. But when he came alone to the laboratory, that crack closed. He could not find the right loose thread to tug at, the way to ask the question. To him the laboratory presented a stone face, unyielding to his pleadings. And whether his death was a suicide or a true accident, his failure to win what he loved killed him. One could consider Lewis, in a way meaningful only to him, the last victim of the 1918 pandemic.

We talked about Friedrich Miescher and Oswald Avery, and Chargaff modulated from philippic to elegiac. Then he said, “I am against the over-explanation of science, because I think it impedes the flow of scientific imagination and associations. My main objection to molecular biology is that by its claim to be able to explain everything, it actually impedes the flow of free scientific explanation. But there is not a scientist I have met who would share my opinion.