Information Is Written in Detail

All Information Is Written in Detail

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 in this text. But the viral information is simple, exceedingly compact, extraordinary 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.

All information is written in exhaustive, careful, redundant detail – how to laugh, how to squeeze, how to walk, how to recognize patterns, how to reproduce, how to digest an apple. Image: © Meg Jorgensen (Elena)

A bacterium uses roughly a million bits of information, which is about one hundred 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 while or a human being need something like five millions bits. The 5X10(9) 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. Everyone 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.