Divergence with Genetic Exchange

Divergence with Genetic Exchange

Divergence with Genetic Exchange

Divergence with Genetic Exchange

Synopsis

The study of genetic exchange resulting from natural hybridization, horizontal gene transfer, and viral recombination has long been marked by controversy between researchers holding different conceptual frameworks. Those subscribing to a doctrine of "species purity" have traditionally been reluctant to recognize inferences suggesting anything other than a marginal role for non-allopatric divergence leading to gene transfer between different lineages. However, an increasing number of evolutionary biologists now accept that there is a growing body of evidence indicating the existence of non-allopatric diversification across many lineages and all domains of biological diversity. Divergence with Genetic Exchange investigates the mechanisms associated with evolutionary divergence and diversification, focusing on the role played by the exchange of genes between divergent lineages, a process recently termed "divergence-with-gene-flow". Although the mechanisms by which such divergent forms of life exchange genomic material may differ widely, the outcomes of interest - adaptive evolution and the formation of new hybrid lineages - do not. Successive chapters cover the history of the field, detection methodologies, outcomes, implications for conservation programs, and the effects on the human lineage associated with the process of genetic transfer between divergent lineages. This research level text is suitable for senior undergraduate and graduate level students taking related courses in departments of genetics, ecology and evolution. It will also be of relevance and use to professional evolutionary biologists and systematists seeking a comprehensive and authoritative overview of this rapidly expanding field.

Excerpt

This book is an investigation into processes associated with evolutionary divergence and diversification. The focus, as the title indicates, is on the role played by the exchange of genes between divergent lineages. This process has been given various monikers, the most recent being “divergence-withgene-flow.” I want to first express my profound relief concerning the degree to which evolutionary biologists in general have embraced a model of diversification that includes some measure of genetic exchange. Many research groups, including my own, have emphasized the important role of gene transfer events in evolution for decades. However, I would be remiss if I did not express some misgivings concerning some of the current research into these processes. As my friends and family members (and especially those people with whom I do not see eye-to-eye) know, I do not hesitate to mention when I think there is a lack of an appreciation of historical precedence. I would argue that often this newest terminology—used in place of what many before us described as natural hybridization, introgression, horizontal gene transfer, viral reassortment, parapatric and/or sympatric divergence, etc.—demonstrates an unfortunate lack of understanding of the rich history of studies of genetic exchange.

Notwithstanding this concern, I once again prefer to emphasize the fact that evolutionary biologists now appear to believe that testing for divergence accompanied by genetic exchange has merit. The order and structure of the various chapters, as with my previous texts, reflect the goal of illustrating the conceptual and biological breadth of genetic exchange-mediated evolutionary processes. I have thousands of Endnote references (10,851 at the time of this writing), most of which discuss web-of-life processes, from which I had to choose the following topics and examples. This means that not only was it necessary to be subjective, but also due to unintentional oversight, I will have minimized some extremely important research. However, as with my most recent two books, I include discussions of viruses, prokaryotes, and eukaryotes. My rationale for discussing clades from all the domains of life remains the same as before. Though the mechanisms by which organisms exchange genomic material differ widely, the outcomes others and I are interested in—adaptive evolution and the formation of new “hybrid” lineages—do not. Furthermore, there remains in some corners a biased outlook on the utility of different organismic groups in defining the “important” evolutionary processes. An interaction I had with a colleague at a Society for the Study of Evolution meeting, I believe, illustrates this point . . .

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.