Year: 2012
Type: book-review
Abstract: ISSN 1948‐6596 news and update book review A case for microbial endemism Biogeography of microscopic organisms: is everything small everywhere?, by Diego Fontaneto (editor) 2011, Cambridge University Press, 365 pp. ISBN: 978‐0‐521‐76670‐8 Price: £60.00 (Hardback); http://www.cambridge.org/ Biogeography of microscopic organisms will be recommended reading for all my students and postdocs interested in microbial biogeography. Yet I admittedly cracked this book with few expec‐ tations. The everything‐is‐everywhere (EiE) discus‐ sion has dominated this growing field for the past decade, and I could not imagine reading 300+ more pages on this topic. Moreover, the chapter list is biased in its coverage towards eukaryotes, whereas I (unfairly) prefer reading about Bacteria, Archaea, and viruses (the last of which are not considered). Despite my initial skepticism, how‐ ever, I am now convinced that Dr. Fontaneto has done the field of microbial biogeography a great service. The compilation provides a thorough dis‐ section of the EiE hypothesis, a wealth of fascinat‐ ing case studies, and testable hypotheses for fu‐ ture research. Perhaps most importantly for the field, it compiles ample evidence for microbial endemism from all corners of microbial life. Part I introduces the EiE hypothesis and its history. Briefly, the idea is that because of their size, microorganisms are not dispersal limited (Baas Becking 1934, Finlay 2002), and as a result there are few, if any, endemic microorganisms. Beyond the introductory section, each chapter is also independently framed in terms of the EiE hy‐ pothesis. This format is enlightening (if a bit re‐ petitive), because it demonstrates that much of the debate lies in what the hypothesis is, as well as whether the data support it. For instance, al‐ though it is not always explicit, the contributing authors vary in their definitions of dispersal. Bass & Boenick (Chapter 6) seem to define dispersal as the movement of individuals to a new location “whether they grow or not (as long as they have the potential to do so).” In contrast, Geml (Chapter 9) estimates migration rates using mod‐ els of gene flow, implicitly focusing on individuals that reproduce and mix with a local gene pool. The middle three sections of the book con‐ sider case studies from biogeographically intrigu‐ ing groups, such as thermophilic bacteria (Chapter 4), lichen fungi (Chapter 10), and microscopic ani‐ mals (Chapters 13 and 14). I envision returning often to these sections in the future for vivid ex‐ amples in writing or teaching. Most of these chap‐ ters conclude that there is evidence for endemism within their focal group. Although innumerable earlier studies have come to this conclusion, the broad diversity of taxa considered in one place drives home the point. For instance, Ganter (Chapter 8) consolidates data from cactophilic yeast isolated from North and South America, the Caribbean Islands, and Australia. Many of these species appear to be endemic to a geographic re‐ gion, whereas only two are ubiquitous among these locales. Similarly, Medina et al. (Chapter 11) conclude that, as for flowering plants, mosses (which disperse as microscopic spores) include both endemic and cosmopolitan species. Beyond a general agreement that some mi‐ croorganisms have restricted distributions, many chapters note the same complications hampering a resolution of the EiE debate. In particular, sev‐ eral discuss how taxonomic resolution and depth of sampling affect the likelihood of observing en‐ demism. Perhaps the clearest cases are compari‐ sons between taxa defined by morphology versus those defined by molecular markers. Another common theme is that, at the very least, the EiE hypothesis is an over‐simplification because size is not the only factor determining microbial disper‐ sal. Foissner (Chapter 5) illustrates this point beautifully with a variety of micrographs that showcase the role of resting cysts in protist dis‐ persal. The differences among the case studies are as informative as their similarities. Although the field is quickly moving towards primarily nucleo‐ tide sequencing, the studies here give the reader of an overview of the methodological and analyti‐ frontiers of biogeography 3.4, 2012 — © 2012 the authors; journal compilation © 2012 The International Biogeography Society
Source: Frontiers of Biogeography
DOI: 10.21425/f5fbg12445
Author: Jennifer B. H. Martiny
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $300
OpenAlex ID: W223348974