Sir
Your News Feature 'Disputed definition' looks at the pitfalls of discussing race with regard to humans (Nature 455, 1025–1026; 2008). Social norms now effectively prohibit, with good cause, the assumption that there are biological distinctions among human races. Thankfully, too, the heyday of eugenics has long since passed.
You do not mention, however, that the term 'race' is often treated as a synonym for the taxonomic rank of subspecies (for example, see E. Mayr Principles of Systematic Zoology 44, McGraw-Hill, 1969). An unwitting reader might infer that the term 'subspecies' is equally problematic and should therefore be equally eschewed. Some, indeed, would argue as much (for example, E. O. Wilson and W. L. Brown Syst. Zool. 2, 97–111; 1953; and R. M. Zink Proc. R. Soc. B 271, 561–564; 2004).
However, 'subspecies' remains a useful taxonomic division that enriches our understanding of evolution and biogeography. It provides a handle for identifiable units of geographic variation and, therefore, frequently acts as impetus for investigations into the evolution of particular species.
Subspecies can be defined as "a collection of populations occupying a distinct breeding range and diagnosably distinct from other such populations" (M. A. Patten and P. Unitt Auk 119, 26–35; 2002), representing a level of biological organization below that of species. This definition is not arbitrary, as there are clear ways of describing a subspecies objectively.
Given the problems associated with the term 'race', conflating 'race' and 'subspecies' is potentially misleading and unnecessarily undermines the proper definition of subspecies. So stop the common practice of using 'race' as a synonym for 'subspecies' (as, for example, in Field Guide to the Birds of North America National Geographic, 5th edn, 2006). Let us relegate that murky term for use by sociologists and politicians enamoured of purported differences among humans.
