"Thank you for sending me a copy of Gene McCarthy’s manuscript On the Origin of New Life Forms [this was the working title of the manuscript at the time of the review] for Oxford Univ. Press. I have now read the entire book, and in fact I could hardly put it down! This is a wonderful, indeed marvelous book that you absolutely must publish ASAP. At the risk of sounding overly ebullient, this is one of the most exciting and potentially revolutionary treatments of evolutionary biology (while still being plausible) that I have encountered in recent memory. The work is scholarly, beautifully researched, remarkably comprehensive, sometimes hyperbolous, and highly provocative (but in a generally positive way). Furthermore the writing itself is exquisite. In each chapter of the book, I found myself relishing not only the thrust of [the author’s] central argument and the prospect of where it might be headed, but also on the multitudinous details, pithy phrases, and extensive quotations from both the recent and ancient literature that [he] has used with great effect to present and defend his arguments."

"The approach that McCarthy has taken is the stuff of which Kuhnian revolutions are built. He has taken many puzzling and sometimes troubling aspects of conventional neo-Darwinian evolutionary thought, and woven them together to motivate a grand novel hypothesis (stabilization theory) that interprets these problematic areas in a new light. Among the contentious subjects that McCarthy reinterprets and purports to resolve in the light of stabilization theory are the following: the concepts and definitions of species and why these have so long remained controversial; the origin and role of karyotypic changes in the evolutionary process (a topic that has been largely neglected since the 1950s); the puzzlement of why different gene trees seem so often seem to support different organismal phylogenies; general uncertainties about the mechanisms and processes underlying reproductive isolation; and the issue of how to reconcile the appearance of punctuated stasis in the fossil record with the well-known mechanisms of traditional population genetics. McCarthy argues that these and other major dilemmas under traditional speciation theory largely dissolve under the evolutionary scenario he develops, wherein hybridization often provides the initial stimulus and fodder for evolutionary change by introducing into lineages a wealth of otherwise unavailable genetic variation (especially karyotypic) from which new species then sometimes emerge as stabilized recombinant derivatives. The hypothesis is bold, at least plausible, difficult to broadly refute, and yet also ultimately testable. Such testing can involve, for example, more critical appraisals of whether (and if so, why) gene trees often lack full concordance with one another in the organismal trees they seem to support. [Is this because of homoplasy and the idiosyncrasies of lineage sorting (as is often supposed in much of the recent literature), or is it because evolution is far more reticulate than formerly imagined] Many other research lines are also suggested, directed for example toward understanding both descriptively and experimentally the actual consequences of interspecific hybridization. Indeed, this book should stimulate fresh evolutionary perspectives, worthy of further exploration, in a wide set of research arenas."

"To my knowledge, there are no other books even remotely comparable to this one either in terms of topic, or in the potential for major impact on the field of evolutionary biology. This book should generate tremendous discussion and interest, even for those who will disagree with its central tenet (and there probably will be many). Although the author is prone to hyperbole throughout the book, and is far too blithely dismissive of traditional evolutionary thought, this book is nonetheless a highly educational read, and a welcome reminder that even 150 years after Darwin, the field of evolutionary biology is still youthful and vibrant, and still provides an intellectually rich and challenging arena for scientific inquiry."

"The rest are minor points. I can’t find that McCarthy has included mention of the large literature and many examples now available on the phenomenon of cytoplasmic capture (e.g. of mtDNA and cpDNA molecules having been transferred across species by introgressive hybridization). This topic would seem to mesh very well with (and add empirical support for) the contention that hybridization is a common phenomenon even in animal populations and that genes can and do move among species rather routinely."

"Technically, the book is in excellent shape and needs little editing. I happened upon only a very few typos, which are listed below. My main technical complaint is that the notes are listed with Roman numerals. I would strongly encourage that these all be converted to regular numbers otherwise, most readers will be extremely frustrated (as I was) by not being able to easily find the important notes that are referred to in the text."

"Typos:

p. 186, line 4: ccan
p. 193, last paragraph: with a membrane-bound nuclei (should be nucleus)

p. 198, 8th line from the bottom has an error
p. 199-200: having could better"

"I will probably want to write a formal review of this book for a scientific journal, so I hope you will keep me informed about your publication schedule and also send me a complementary copy of the book as soon as it becomes available. You may convey my identity to the author, and if you wish you may use the following quote for promotional purposes:"

"McCarthy masterfully develops an extended argument for a paradigm shift in evolutionary biology from the traditional view that each new species arises gradually from a single ancestral form, to the novel suggestion that each new life form originates suddenly when its recombinant karyotype becomes genetically stabilized following a hybridization event between two distinct ancestors. This bold hypothesis the stuff of which Kuhnian revolutions potentially emerge is presented with eloquence, extensive scholarship, and verve. Importantly, the hypothesis entails empirically testable genetic mechanisms and evolutionary predictions, and thus may stimulate a sweeping research agenda."