With aching hands and bleeding feet

We dig and heap, lay stones on stone;

We bear the burden and the heat

Of the long day, and wish t'were done.

Not till the hours of light return

All we have built we do discern.

Matthew Arnold

The promise of the human genome project to transform biology and medicine is alluring. To document the sequence of bases, three billion in total, that make up the building blocks of human DNA is a formidable task requiring not only the knowledge and skills of the biochemist, geneticist, and molecular biologist but also the technological expertise of engineers and information scientists. Detailed genetic maps have already been constructed to resolutions of 1-2 centimorgans (cM),1 and physical mapping has resulted in the integration into the genetic map of over 30 000 genes.2 Similar efforts have led to the complete sequencing of smaller organisms, such as the bacterium Escherichia coli, the yeast Saccharomyces cerevisiae, and the worm Caenorhabditis elegans, many parts of which are homologues of sequences in the human genome.

New goals for the US Human Genome Project were defined in October 1998.3 These have included a commitment to complete a third of the human sequence and a “working draft” to cover 90% of the genome by 2001. The whole genome will be sequenced by 2003, two years in advance on the original target date. Sequencing technology will be improved and speeded up, and costs of sequencing each base pair will be reduced from current levels of $0.50 to an expected $0.25 within the next five years. There will be a drive to identify sequence variation, particularly single base pair differences (known as single nucleotide polymorphisms, SNPs), and to develop technologies for their rapid, large scale identification in populations. An …