The volume is widely read, in fact, so widely read it has run… it's gone out of print and Harvard University Press has decided to republish it and will come out new again next year. And they asked me to write a new foreword for the reason that there is still some uncertainty because Provine, for instance, has published a report on the evolutionary synthesis which is quite in conflict with my version of it. And I analyzed the whole situation and I discovered that there were three periods actually in evolutionary biology after the year 1900. After the rediscovery of the Mendelian publication, the so-called Mendelians took over the explanation of evolution and these were Hugo de Vries of the Netherlands, Bateson from England, and Johannsen from Denmark. And they all three were mutationists, they believed that evolution proceeded by major mutations that produced a new species in a single step, and all of… all three of them were very much opposed to natural selection, they didn't believe in natural selection. And that was the, so to speak, official viewpoint on selection among the geneticists. Well, this period lasted… and TH Morgan… included, he also accepted this viewpoint. Then, beginning 1916 a number of papers came out, one particularly by RA Fisher which… and the later findings in the Morgan lab that many mutations could be very small changes and evolution could happen very gradually and therefore there was no objection any more to natural selection, and the new viewpoint of the population geneticists developed between 1916 and 1932 in which this was the standard interpretation of evolution and it was quite in consonance with Darwinian interpretation. And this was the synthesis between the new genetic thinking, the populational genetic thinking, and the Darwinian interpretation, but it wasn't the evolutionary synthesis. The evolutionary synthesis covered the years 1937 to 1947 and was initiated by the publication of [Theodosius] Dobzhansky's Genetics and the Origin of Species. And as I think I already mentioned some time earlier, Dobzhansky had the great fortune and advantage to have been a naturalist as a youngster and he was a collector of butterflies and beetles and he had become a specialist of the Coccinella beetles, the ladybird beetles. And so he was fully familiar with what species are and what speciation is and with the whole thinking of the naturalists in the subject. But then when he was 27 years old he got a scholarship to come to America from Russia where he was, and joined the Morgan lab where he came under the influence not only of Morgan but also particularly of [Alfred] Sturtevant. And he acquired the thinking of the geneticists, the population geneticists, so he had two of these viewpoints, two of these sets of concepts and ideas which he found were compatible if properly interpreted. And this compatibility he presented in his 1937 book Genetics and the Origin of Species and this led to a synthesis of the fields of the naturalists and the fields of the population geneticists. And it must be emphasized that in the writings of the population geneticists prior to Dobzhansky's book you get hardly… you find hardly a word about speciation, species, macro-evolution, that was something that geneticists who worked with a single gene pool could not possibly deal with, could not possibly handle and therefore they simply ignored it. And the important step in the evolutionary synthesis of the period 1937 to ’47 was that the two fields – the study of adaptation which the geneticists were doing, and the study of the origin of organic diversity which the naturalists were doing – were shown to be compatible with each other and were fused together into one single field, the field of evolutional biology or as it is called, the field of the evolutionary synthesis. So that was really for the whole field of evolution an absolutely crucial period, this coming together of the naturalists and the population geneticists.