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Fifty years ago, the philosopher Olaf Stapledon published a novel, Sirius, which explores some of the depths of loneliness and alienation to which genetic engineering might lead. Stapledon knew nothing of DNA and molecular biology, but he foresaw the possibility of genetic engineering and saw that it would give rise…
The team gathered samples over the course of a year from sewage treatment plants in 71 different cities in 31 states, chosen for their geographic spread and range of obesity rates. The leanest city sampled was Steamboat Springs, Colorado, with an obesity rate of 13.5 percent, while the heaviest was St. Joseph…
The standard DNA 'prism' is a gel electrophoresis column, that is, a long tube filled with jelly through which an electric current is passed. A solution containing the scissored stretches of DNA, all jumbled together, is poured into one end of the tube. The DNA fragments are all electrically attracted to the negative…
Now it is generally true that the very greatest scientists in each discipline are unifiers. This is especially true in physics. Newton and Einstein were supreme as unifiers. The great triumphs of physics have been triumphs of unification. We almost take it for granted that the road of progress in physics will be a…
The century of biology upon which we are now well embarked is no matter of trivialities. It is a movement of really heroic dimensions, one of the great episodes in man's intellectual history. The scientists who are carrying the movement forward talk in terms of nucleo-proteins, of ultracentrifuges, of biochemical…
Every vitamin is made by living cells — either our own, or in other species. Vitamin D is produced in our skin, for example, when sunlight strikes a precursor of cholesterol. A lemon tree makes vitamin C out of glucose. Making a vitamin is often an enormously baroque process. In some species, it takes 22 different…
Life began in water, and every single function of life takes place in an aqueous environment. A profound way of classification in chemistry is the relation and interaction between molecules, or groups within molecules, and water. Molecules (or parts of molecules) can attract water in which case they are called…
The major credit I think Jim and I deserve ... is for selecting the right problem and sticking to it. It's true that by blundering about we stumbled on gold, but the fact remains that we were looking for gold. Both of us had decided, quite independently of each other, that the central problem in molecular biology was…
My own thinking (and that of many of my colleagues) is based on two general principles, which I shall call the Sequence Hypothesis and the Central Dogma. The direct evidence for both of them is negligible, but I have found them to be of great help in getting to grips with these very complex problems. I present them…
When I see the butterfly, I imagine in my mind's eye the extraordinary chemical machinery of life, the winding loom of he DNA, the proteins linking like lock and key, the ceaseless hubbub of molecular commerce that goes on behind the scenes, from egg, to caterpillar, to chrysalis, to adult. Surely, no land of faerie…
Hard problems often yield before science, and though we still don’t understand how every complex biochemical system evolved, we are learning more every day. After all, biochemical evolution is a field in still its infancy. If the history of science teaches us anything, it is that what conquers our ignorance is…
Some atavisms can be produced in the laboratory. The most amazing of these is that paragon of rarity, hen’s teeth. In 1980, E. J. Kollar and C. Fisher at the University of Connecticut combined the tissues of two species, grafting the tissue lining the mouth of a chicken embryo on top of tissue from the jaw of a…
By sequencing the DNA of various species and measuring how similar these sequences are, we can reconstruct their evolutionary relationships. This is done by making the entirely reasonable assumption that species having more similar DNA are more closely related—that is, their common ancestors lived more recently. These…
It [molecular biology] is concerned particularly with the forms of biological molecules and with the evolution, exploitation and ramification of these forms in the ascent to higher and higher levels of organization. Molecular biology is predominantly three- dimensional and structural—which does not mean, however, that…
Whales were long an enigma, but recently our knowledge of whale evolution has become rather rich. Molecular genetic evidence (see Chapter 10 for the nature of this kind of evidence) shows that the closest living cousins of whales are hippos, then pigs, then ruminants. Even more surprisingly, the molecular evidence…