In the late 1970s, when I was a professor at Caltech, I pioneered four instruments for analyzing genes and proteins that revolutionized modern biology - and one of these, the automated DNA sequencer, enabled the Human Genome Project.

A DNA sequence for the genome of bacteriophage ΦX174 of approximately 5,375 nucleotides has been determined using the rapid and simple 'plus and minus' method. The sequence identifies many of the features responsible for the production of the proteins of the nine known genes of the organism, including initiation and termination sites for the proteins and RNAs. Two pairs of genes are coded by the same region of DNA using different reading frames.

If you know the mother's genome and the father's genome, and you see that the children have some genes that neither parent has, then you know that difference is either a mutation or a processing error.

Mutations can arise anywhere in the genome, in gene DNA and noncoding DNA alike. But mutations to genes have bigger consequences: They can disable proteins and kill a creature.

An important finding is that by determining the genome sequences of an entire family, one can identify many DNA sequencing errors and thus greatly increase the accuracy of the data. This will ultimately help us understand the role of genetic variations in the diagnosis, treatment, and prevention of disease.

The systems approach to biology will be the dominant theme in medicine.