Genome Analysis Shows Humans Survive on Low Number of Genes
Their principal discovery is how few human genes there seem to be. Textbooks have long pegged the number of human genes at around 100,000, but with the sequence of human DNA units in hand the two teams have found far fewer than expected. Dr. Venter says he has identified 26,588 protein-coding genes for sure and another 12,000 possible genes. The consortium says there are 30,000 to 40,000 human genes. Both sides prefer the lower end of their range, since their methods of gene discovery tend to predict more genes than they believe exist.

The low number of human genes — say 30,000 — can be seen as good for medicine because it means there are fewer genes to understand.

The impact on human pride is another matter. Of the only two other animal genomes sequenced so far, the roundworm has 19,000 genes and the fruit fly, also a standard laboratory organism, 13,000. Both teams devote part of their huge articles to discussing how it is that humans are more complicated than simple invertebrate animals even though they possess not that many more genes.

Despite these face-saving efforts, human self-esteem may be in for further blows as genome analysis progresses. Dr. Venter said he could find only 300 human genes that had no recognizable counterpart in the mouse. The mouse, though a fellow mammal, last shared a common ancestor with people 100 million years ago, time in which many more genetic differences might have been expected to develop.

Given the minor difference between man and mouse, Dr. Venter said he expected the chimpanzee, which parted company from the human line only five million years ago, to have an almost identical set of genes as people but to possess variant forms of these genes.
http://www.nytimes.com/2001/02/11/health/11GENO.html?pagewanted=all