The term means a number of things to different people, it appears. In November 2002, Carl Wunsch of MIT published a report in Science, “What Is the Thermohaline Circulation?,” in which he noted that the expression has been used in leading journals to signify at least seven different phenomena (circulation at the abyssal level, circulation driven by differences in density or buoyancy, “meridional overturning circulation of mass,” and so on)— though all have to do with ocean circulations and the transfer of heat, the cautiously vague and embracing sense in which I have employed it here.
34
The indigestible parts of giant squid, in particular their beaks, accumulate in sperm whales’ stomachs into the substance known as ambergris, which is used as a fixative in perfumes. The next time you spray on Chanel No. 5 (assuming you do), you may wish to reflect that you are dousing yourself in distillate of unseen sea monster.
35
There are actually twenty-two naturally occurring amino acids known on Earth, and more may await discovery, but only twenty of them are necessary to produce us and most other living things. The twenty-second, called pyrrolysine, was discovered in 2002 by researchers at Ohio State University and is found only in a single type of archaean (a basic form of life that we will discuss a little further on in the story) called Methanosarcina barkeri.
36
To illustrate, humans are in the domain eucarya, in the kingdom animalia, in the phylum chordata, in the subphylum vertebrata, in the class mammalia, in the order primates, in the family hominidae, in the genus homo, in the species sapiens. (The convention, I’m informed, is to italicize genus and species names, but not those of higher divisions.) Some taxonomists employ further subdivisions: tribe, suborder, infraorder, parvorder, and more.
37
The formal word for a zoological category, such as phylum or genus. The plural is taxa.
38
We are actually getting worse at some matters of hygiene. Dr. Maunder believes that the move toward low-temperature washing machine detergents has encouraged bugs to proliferate. As he puts it: “If you wash lousy clothing at low temperatures, all you get is cleaner lice.”
39
Actually, quite a lot of cells are lost in the process of development, so the number you emerge with is really just a guess. Depending on which source you consult the number can vary by several orders of magnitude. The figure of ten thousand trillion (or quadrillion) is from Margulis and Sagan, 1986.
40
Leeuwenhoek was close friends with another Delft notable, the artist Jan Vermeer. In the mid-1660s, Vermeer, who previously had been a competent but not outstanding artist, suddenly developed the mastery of light and perspective for which he has been celebrated ever since. Though it has never been proved, it has long been suspected that he used a camera obscura, a device for projecting images onto a flat surface through a lens. No such device was listed among Vermeer’s personal effects after his death, but it happens that the executor of Vermeer’s estate was none other than Antoni van Leeuwenhoek, the most secretive lens-maker of his day.
41
An auspicious date in history: on the same day in Kentucky, Abraham Lincoln was born.
42
Darwin was one of the few to guess correctly. He happened to be visiting Chambers one day when an advance copy of the sixth edition of Vestiges was delivered. The keenness with which Chambers checked the revisions was something of a giveaway, though it appears the two men did not discuss it.
43
By coincidence, in 1861, at the height of the controversy, just such evidence turned up when workers in Bavaria found the bones of an ancient archaeopteryx, a creature halfway between a bird and a dinosaur. (It had feathers, but it also had teeth.) It was an impressive and helpful find, and its significance much debated, but a single discovery could hardly be considered conclusive.
44
In 1968, Harvard University Press canceled publication of The Double Helix after Crick and Wilkins complained about its characterizations, which the science historian Lisa Jardine has described as “gratuitously hurtful.” The descriptions quoted above are after Watson softened his comments.
