CORRESPONDENCE

concepts of what constitutes the evolutionary synthesis. He focuses specifically on the nomothetic character of selection theory. However, for me, the term synthesis applies more broadly to the integration of this concept with empirical data from the fossil record, the nature of species and speciation, and mendelian and population genetics, to form a unified explanation of evolutionary patterns and processes. The formulation of the evolutionary synthesis was extensively reviewed by Mayr and Provine6. Mayr7 specifically cited the concept of macroevolution that was promulgated at that time: ‘…all the available evidence indicates that the origin of the higher categories is a process which is nothing but an extrapolation of speciation. All the processes and phenomena of macroevolution and the origin of the higher categories can be traced back to intraspecific variation…’. This concept of evolution is applicable primarily to sexually reproducing diploid organisms and can only be indirectly applied to prokaryotes, which dominated the first 2.5 billion years of life. My call for a ‘new ’ synthesis does not indicate a rejection of natural selection, but is a summons for broader recognition and integration of data from molecular developmental biology, and knowledge of the history of the earth and its biota, which were unknown to Darwin and those who framed the evolutionary synthesis