MARBENA Creating a long-term infrastructure for MARine Biodiversity research in the European economic area and the Newly Associated states

Genetic Biodiversity in Marine Ecosystems

Topic 1. Measuring managing and conserving genetic resources in natural marine systems

Please, click on 'add message' to start a new discussion item, or react to one of the posted messages by clicking on the 'respond to message' button at the end of that message.

Note: mind the size of your message. Your message should not exceed one page. Or else, send it to me and I will post it on the forum. There's a limit on number of characters to be posted via the forum. With the best regards, your forum administrator.

Chairmen: Thierry Backeljau and Ferruccio Maltagliati

To bridge or not to bridge

Having just returned from the 11th International Echinoderm Conference, I found some jolly interesting, highly controversial MARBENA messages in my inbox. In my opinion, one of the main argumentations of the first topic can however be summarized in one sentence: “studies of genetic diversity are nowadays important and regarded as very hot when it comes to replying to the biodiversity crisis, while the more classical morphological (phenotypical) approach is thought to be too weak to cogently formulate an answer to the “sixth mass extinction” as E.O. Wilson so adequately termed it. I can only hope that it should be clear to everybody that both approaches work complementary rather than competively. Nevertheless, I here want to score a three-pointer for the morphospecies team and - if missed - leave the rebound two-pointer for the “genetic” team. We all know that oceans cannot be trapped into aquariums and as such that: species-concepts are and continue to be heavily debated (amongst many others, see the excellent revision by Wheeler & Meier 2000), gene evolution not necessarily equals organism evolution, cryptic species are, by implication, difficult to discover on a morphological basis and that concepts as metapopulation or minimum viable population size seem to be rather taxon specific, but we collectively seem to forget the important advances in biodiversity description and understanding that were, until the last decades, exclusively based on pure comparative organismal studies. The material on which our understanding is largely founded is deposited in natural history collections worldwide. Alas, even though this material is (largely) available it remains grossly understudied. Moreover, “geneticists” by far prefer to use new, adequately preserved material for their studies (which is, of course, understandable). Nevertheless, the importance of these historical collections is perhaps best emphasized by their sheer size: f.i. McCarter et al. (2001) estimate that some 250 million specimens are deposited in the American Museum of Natural History, the Smithsonian, the Natural History Museum, London and the Field Museum in Chicago. It should be clear that these historical collections hold crucial information that can and should help us to understand past and present biodiversity even more thoroughly. But let’s not divert from the subject too much, this message is not intended as paean for museum science. The point to take home, I believe, is not that one approach is by definition better than the other; but that we’d better devote some more attention to what we have already collected rather than start de novo. Although I do not want to exaggerate John Ray’s supposed to be cynical definition of species (“species are merely what competent taxonomists say they are”) (see McQuat 2001) but, again and again comparative anatomic, morphologic and geographic studies have de-veiled bits and pieces of biodiversity. For instance, our team has recently uncovered species complexes in supposed to be well-known holothuroid species, “simply” by doing sound taxonomy (Massin et al. in press). In short, the fastest way to really do something about the current biodiversity crisis is to: (i) identify gaps in taxonomical knowledge, both on a local and a global scale; (ii) train more taxonomists (especially in developing countries where the plethora of biodiversity is located; (iii) respect each other’s work more openly and (iv) continue to bridge the gap between the molecular and the morphological. With the Global taxonomy Initiative, an important bridge is fortunately under construction, now we’ll only need pedestrians on both sides to make it useful. References: Wheeler Q.D., MeierR., 2000. Species concepts and Phylogenetic Theory. Wheeler Q.D. & Meier R. (eds), Columbia University Press, New York. Massin C., Samyn Y., Thandar A.S., in press. The genus labidodemas (Aspidochirotida: Holothuriidae) revisited with description of three new species and with repositioning of Holothuria (Irenothuria) maccullochi Deichmann, 1958. Journal of natural History. McCarter J., Boge G., Darlow G., 2001. Safeguarding the World’s Natural Treasures. Science 294: 2099-2101. McQuat G., 2001. Cataloguing power: deliniating ‘competent naturalists’ and the meaning of species in the British Museum. The British Journal for the History of Science 34: 1-28.

Posted by Yves Samyn on 2003-10-15 15:11:01.693

Lookup Yves Samyn in IMIS.

General coordination: Carlo Heip ,Herman Hummel and Pim van Avesaath Web site and conference hosted by VLIZ