Field of Science

Today It Pours

I opened up my e-mail and Reader this morning, and found so many interesting things, from the fascinating to the tragic, I barely know which to comment on. I'll just introduce a few below:

First, the tragic: The Yangtze River Dolphin is Officially No More. Lipotes vexillifer thus becomes the first known cetacean to become extinct due to human activity, and probably only the third taxon recognised at family level to do so (after Thylacinus and Raphidae). This is truly a sad moment in ecological history.

Second, Kevin Z has written a good piece on the negative effect measurement of "impact factors" has had on biology, and on taxonomy in particular. I ranted on a similar subject yesterday, but Kevin's done a better job than I did. His comments on unreliable species IDs dovetail nicely with what I was saying.

A couple of things are going to require a bit more commentary on my part, but I'll mention them now in case I don't get back to them. First, a paper in PLoS One on the phylogenetic position of Acoelomorpha by Philippe et al. Acoelomorpha are gutless flatworm-like animals that were once including in Platyhelminthes (the flatworms proper), but in recent years have been regarded as the sister group to all other bilaterian animals. Philippe et al. agree with the removal of acoelomorphs from Platyhelminthes, but also disagree with their basalmost position in Bilateria, instead finding them close to Deuterostomia. I'm feeling a bit sceptical, but I'll have to actually read the paper in detail and get back to you.

There's also a couple of very interesting-looking papers in today's Nature on the distribution of biodiversity in tropical rainforests. The "News and Views" article by N. E. Stork for them is here, if you can access it. My apologies to those of you who can't - I haven't seen a publicly available release. I'll quote the two paragraphs from the N&V summarising the results:

With the help of a team of locally trained parataxonomists, Novotny et al. have compiled such a database of records for three groups of rainforest insects: those that feed on foliage, wood and fruit. They show that there is a low rate of change in species composition, or 'β diversity', across 75,000 km2 (an area equivalent to that of South Carolina or Ireland) of continuous lowland rainforest in Papua New Guinea. This contrasts with the previous evidence, as discussed by Novotny et al., of high β diversity for insects in the forest canopy and with changes in β diversity with latitude, altitude and climatic gradients.

In the second new paper discussed here, Dyer et al. describe how they carried out an equivalent analysis in the New World and have come to a different conclusion. Their approach required examination of hundreds of thousands of host-specificity feeding records for butterfly and moth caterpillars, from as far back as 1936 and from areas ranging from Canada to Brazil. In contrast to Novotny and colleagues, they find that, on average, the number of tree species on which an insect species feeds is fewer in the tropics than in temperate parts of the New World. They suggest that higher specialization in the tropics might be because of more intense interactions between an insect and its food source, as might be caused by more distinct secondary chemicals in tropical plants than in temperate plants.

Again, I'll get back to you once I've read the papers fully.


  1. It is sad the dolphin is gone and I bet it is only the first of a long list of species to go extinct in China in the coming decades.

    Some corrections though; It's true that Thylacinus was the last remaining representative of its lineage. The dodos however,are nowadays included within Columbidae so they don't count. Instead, you could replace them with Sylviornithidae, Aptornithidae, Dinornithidae or Aepyornithidae. Each of these 'families' has gone extinct in the last 1000 or so years due to human activities. Also, there is the mysterious Plesiorycteropus from Madagascar which is placed in its own 'family' and sometimes even its own 'order', Bibymalagasia. All of these are higher level taxons so far more then three have gone extinct.

  2. I decided to be generous about the dodos - 'family' is only an arbitrary construct anyway :-). In regard to the others - d'oh, d'oh and d'oh! Especially for Aptornithidae and Dinornithidae (you could add Anomalopterygidae to that too, for that matter, though it seems pretty well-established that Anomalopterygidae is paraphyletic to Dinornis) - there is no way a New Zealander should have forgotten those.

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