  Bets placed during the HGP over how many genes would be discovered, as well as surprise expressed when far fewer than the original estimate were found (about 25,000–30,000 rather than 100,000—the rice genome apparently has more genes!) (Normile and Pennisi 2002; Pennisi 2003), suggest that “gene”—a term introduced by Wilhelm Johannsen in 1909—names a well-defined concept. The report that because of alternate splicing each gene is responsible for three or four proteins makes the same assumption. As does drawing distinctions between normal and abnormal genes, or seeking to isolate disease genes. The assumption is not very well substantiated, however. Philosophers of biology recognize that the genes of classical genetics, molecular genetics, evolutionary genetics, and more recently developmental genetics do not necessarily map onto each  other.[13] Difficulties arriving at a definitive gene concept arise even when we confine ourselves to contemporary molecular biology. Evelyn Fox Keller (2000) points out an irony which has ensued from the HGP's successes: even though gene-talk is more pervasive than ever in the popular and scientific presses, the concept of the gene, whether defined structurally or functionally, has been “radically undermined” (p. 5). Keller provides this description of current laboratory practices: “As we listen to the ways in which the term is now used by working biologists, we find that the gene has become many things—no longer a single entity but a word with great plasticity, defined only by the specific experimental context in which it is used” (p. 69).