They are the largest animals* ever to evolve on the planet Earth, larger by far than the dinosaurs. An adult blue whale can be thirty meters long and weigh 150 tons. Many, especially the baleen whales, are placid browsers, straining through vast volumes of ocean for the small animals on which they graze; others eat fish and krill. The whales are recent arrivals in the ocean. Only seventy million years ago their ancestors were carnivorous mammals who migrated in slow steps from the land into the ocean. Among the whales, mothers suckle and care tenderly for their offspring. There is a long childhood in which the adults teach the young. Play is a typical pastime. These are all mammalian characteristics, all important for the development of intelligent beings.
* Some sequoia trees are both larger and more massive than any whale.
The sea is murky. Sight and smell, which work well for mammals on the land, are not of much use in the depths of the ocean. Those ancestors of the whales who relied on these senses to locate a mate or a baby or a predator did not leave many offspring. So another method was perfected by evolution; it works superbly well and is central to any understanding of the whales: the sense of sound. Some whale sounds are called songs, but we are still ignorant of their true nature and meaning. They range over a broad band of frequencies, down to well below the lowest sound the human ear can detect. A typical whale song lasts for perhaps fifteen minutes; the longest, about an hour. Often it is repeated, identically, beat for beat, measure for measure, note for note. Occasionally a group of whales will leave their winter waters in the midst of a song and six months later return to continue at precisely the right note, as if there had been no interruption. Whales are very good at remembering. More often, on their return, the vocalizations have changed. New songs appear on the cetacean hit parade.
Very often the members of the group will sing the same song together. By some mutual consensus, some collaborative songwriting, the piece changes month by month, slowly and predictably. These vocalizations are complex. If the songs of the humpback whale are enunciated as a tonal language, the total information content, the number of bits of information in such songs, is some 106 bits, about the same as the information content of the Iliad or the Odyssey. We do not know what whales or their cousins the dolphins have to talk or sing about. They have no manipulative organs, they make no engineering constructs, but they are social creatures. They hunt, swim, fish, browse, frolic, mate, play, run from predators. There may be a great deal to talk about.
The primary danger to the whales is a newcomer, an upstart animal, only recently, through technology, become competent in the oceans, a creature that calls itself human. For 99.99 percent of the history of the whales, there were no humans in or on the deep oceans. During this period the whales evolved their extraordinary audio communication system. The finbacks, for example, emit extremely loud sounds at a frequency of twenty Hertz, down near the lowest octave on the piano keyboard.. (A Hertz is a unit of sound frequency that represents one sound wave, one crest and one trough, entering your ear every second.) Such low-frequency sounds are scarcely absorbed in the ocean. The American biologist Roger Payne has calculated that using the deep ocean sound channel, two whales could communicate with each other at twenty Hertz essentially anywhere in the world. One might be off the Ross Ice Shelf in Antarctica and communicate with another in the Aleutians. For most of their history, the whales may have established a global communications network. Perhaps when separated by 15,000 kilometers, their vocalizations are love songs, cast hopefully into the vastness of the deep.
For tens of millions of years these enormous, intelligent, communicative creatures evolved with essentially no natural enemies. Then the development of the steamship in the nineteenth century introduced an ominous source of noise pollution. As commercial and military vessels became more abundant, the noise background in the oceans, especially at a frequency of twenty Hertz, became noticeable. Whales communicating across the oceans must have experienced increasingly greater difficulties. The distance over which they could communicate must have decreased steadily. Two hundred years ago, a typical distance across which finbacks could communicate was perhaps 10,000 kilometers. Today, the corresponding number is perhaps a few hundred kilometers. Do whales know each other’s names? Can they recognize each other as individuals by sounds alone? We have cut the whales off from themselves. Creatures that communicated for tens of millions of years have now effectively been silenced.*
* There is a curious counterpoint to this story. The preferred radio channel for interstellar communication with other technical civilizations is near a frequency of 1.42 billion Hertz, marked by a radio spectral line of hydrogen, the most abundant atom in the Universe. We are just beginning to listen here for signals of intelligent origin. But the frequency band is being increasingly encroached upon by civilian and military communications traffic on Earth, and not only by the major powers. We are jamming the interstellar channel. Uncontrolled growth of terrestrial radio technology may prevent us from ready communication with intelligent beings on distant worlds. Their songs may go unanswered because we have not the will to control our radio-frequency pollution and listen.
And we have done worse than that, because there persists to this day a traffic in the dead bodies of whales. There are humans who hunt and slaughter whales and market the products for lipstick or industrial lubricant. Many nations understand that the systematic murder of such intelligent creatures is monstrous, but the traffic continues, promoted chiefly by Japan, Norway and the Soviet Union. We humans, as a species, are interested in communication with extraterrestrial intelligence. Would not a good beginning be improved communication with terrestrial intelligence, with other human beings of different cultures and languages, with the great apes, with the dolphins, but particularly with those intelligent masters of the deep, the, great whales?
For a whale to live there are many things it must know how to do. This knowledge is stored in its genes and in its brain. The genetic information includes how to convert plankton into blubber; or how to hold your breath on a dive one kilometer below the surface. The information in the brain, the learned information, includes such things as who your mother is, or the meaning of the song you are hearing just now. The whale, like all the other animals on the Earth, has a gene library and a brain library.
The genetic material of the whale, like the genetic material of human beings, is made of nucleic acids, those extraordinary molecules capable of reproducing themselves from the chemical building blocks that surround them, and of turning hereditary information into action. For example, one whale enzyme, identical to one you have in every cell of your body, is called hexokinase, the first of more than two dozen enzyme-mediated steps required to convert a molecule of sugar obtained from the plankton in the whale’s diet into a little energy – perhaps a contribution to a single low-frequency note in the music of the whale.
The information stored in the DNA double helix of a whale or a human or any other beast or vegetable on Earth is written in a language of four letters – the four different kinds of nucleotides, the molecular components that make up DNA. How many bits of information are contained in the hereditary material of various life forms? How many yes/no answers to the various biological questions are written in the language of life? A virus needs about 10,000 bits – roughly equivalent to the amount of information on this page. But the viral information is simple, exceedingly compact, extraordinarily efficient. Reading it requires very close attention. These are the instructions it needs to infect some other organism and to reproduce itself – the only things that viruses are any good at. A bacterium uses roughly a million bits of information – which is about 100 printed pages. Bacteria have a lot more to do than viruses. Unlike the viruses, they are not thoroughgoing parasites. Bacteria have to make a living. And a free-swimming one-celled amoeba is much more sophisticated; with about four hundred million bits in its DNA, it would require some eighty 500-page volumes to make another amoeba.
A whale or a human being needs something like five billion bits. The 5 x 109 bits of information in our encyclopaedia of life – in the nucleus of each of our cells – if written out in, say, English, would fill a thousand volumes. Every one of your hundred trillion cells contains a complete library of instructions on how to make every part of you. Every cell in your body arises by successive cell divisions from a single cell, a fertilized egg generated by your parents. Every time that cell divided, in the many embryological steps that went into making you, the original set of genetic instructions was duplicated with great fidelity. So your liver cells have some unemployed knowledge about how to make your bone cells, and vice versa. The genetic library contains everything your body knows how to do on its own. The ancient information is written in exhaustive, careful, redundant detail – how to laugh, how to sneeze, how to walk, how to recognize patterns, how to reproduce, how to digest an apple.