Sir

Many publications by taxonomists are not included in the Science Citation Index (SCI), as pointed out in Correspondence by A. G. Valdecasas et al. (Nature 403, 698; 2000) and by F. T. Krell (Nature 405, 507–508, 2000). E. Garfield (Nature 413, 107; 2001), on the other hand, pointed out some citation classics in taxonomy based on the SCI.

Your correspondents fail to mention the real reason most taxonomists are not included in the SCI: the way taxonomic research is cited means it does not feature in references. In referring to the name of a species, it is customary to state the name(s) of the author(s) after the species name, sometimes abbreviated and with the year of publication of the first description of the species. This citation method is ignored by the SCI and other citation indexes, which is why these scientists do not get the credit they deserve, even though each use of a species name in fact represents a citation.

A quick look in the ISI Web of Science 1988–2001 [http://www.isinet.com/isi/products/citation/wos/index.html] shows that the most frequently cited scientists are the authors who named the bacterium Escherichia coli (108,262 citations), the yeast Saccharomyces cerevisiae (43,403) and the fruitfly Drosophila melanogaster (14,451). To put these numbers into perspective, Albert Einstein is cited 'only' 11,920 times.