Bits and genes: A comparison of the natural storage of information in DNA and digital magnetic recording

Man records information in machine-readable form on magnetic tape while Nature stores the structural and operational information of a living organism along a digitally-encoded molecule of DNA in each cell. The data on magnetic tape is written in eight parallel tracks and is organized in bytes, records and reels. In DNA two tracks are used and the corresponding units are codons, genes, and chromosomes. The magnetic transfer method by which information on tape may be copied onto a blank tape is analogous to the replication process whereby a strand of DNA can generate a complementary strand during cell division. Copying is also used in the transcription-translation process by which the information contained along the DNA molecule is interpreted to give a sequence of amino acids from which the protein needed for cell growth is obtained. In both magnetic tapes and DNA, redundancy in the stored data is used to detect and correct errors. The principal difference between the two data storage methods is found in the writing process. A DNA tape is not written but rather made from another DNA molecule by random mutations at the bit level and then by sorting and merging different records from two old tapes.