Excuse the belatedness of this post, I had a talk to prepare.
The master list for this week is here. Only those categories with more than one paper will be considered. Taxonomy will be exempt, because new species descriptions isn’t the kind of thing I can choose between.
Heikkilä M, Kaila L, Mutanen M, Peña C, Wahlberg N. 2012. Cretaceous origin and repeated tertiary diversification of the redefined butterflies. Proc. R. Soc. B 279, 1093-1099.
What we recognise as butterflies are actually members of three superfamilies, collectively referred to as the Rhopalocera: the Papilionoidea (most butterflies), Hesperioidea (skippers), and Hedyloidea (“moth-butterflies”). This study confirms that this three superfamily splitting is erroneous, with Papilionidae (member of the Papilionoidea) lying at the base of a clade that includes all three superfamilies. Hence, the correct way to refer to split up the butterflies is to refer to all of them as Papillionoidea, including the hesperioids and hedyloids, rendering the term Rhopalocera synonymous with Papilionoidea. Personally, I think the analysis is fairly robust, and I trust this result. The other big part of the paper concerns their diversification through time, employing the molecular clock. The results largely agree with what the fossil record has to say, with both this paper and the record suggesting extensive diversification after the KT event, most probably due to the associated angiosperm radiation.
Hilger HH & Cole TCH. 2012. Evolutionärer Stammbaum der Tracheophyten – neue Zusammenhänge. Biologie in unserer Zeit 42, 14-15.
This paper’s in German, but it wins because it has an up-to-date tree of the trachaeophytes, and that’s always useful.
Andrew ME, Wulder MA, Coops NC & Baillargeon G. 2012. Beta-diversity gradients of butterflies along productivity axes. Global Ecology and Biogeography 21, 352-364.
This paper’s a straight-forward test of the idea that the productivity of an ecosystem has a great influence on its species composition. The hypothesis turns out to be true, at least for butterflies.
Sivakumar G, Xu J, Thompson RW, Yang Y, Randol-Smith P & Weathers PJ. 2012. Integrated green algal technology for bioremediation and biofuel. Bioresource Technology 107, 1-9.
I know very little about this stuff, but occasional guest-blogger Sophie alerted me to it and says it’s a great review paper for anyone interested in the sustainable production of oil and fuel from algae.
Cook LM, Grant BS, Saccheri IJ & Mallet J. in press. Selective bird predation on the peppered moth: the last experiment of Michael Majerus. Biology Letters.
This is one of those annoying online prepub thingies, but I choose it this week anyway. Refer to Jerry Coyne for a summary of the paper (or read it yourself, it’s open access and very easy to read). I actually used it in my recent talk, since it drives the nail in the coffin of all the doubts about the peppered moth story (if you don’t know it somehow, wait a few days until I get the talk’s post up). This paper is based on the data of Michael Majerus, a scientist who worked a lot with peppered moths and other cases of melanism in evolution, publishing a great book on the subject. However, he died before having the chance to publish this data, which he had painstakingly gathered over the several years (he had to go as far as climbing trees to check for moth nesting sites to get it!), so this posthumous analysis (by other researchers who worked with melanism in evolution) does him justice.
Sargent R-M. 2012. From Bacon to Banks: The vision and the realities of pursuing science for the common good. Studies in History and Philosophy of Science Part A 43, 82-90.
This is a topic I often struggle with. On the one hand, my view of science, and how I conduct it, is as a hedonistic enterprise, where knowledge is gained just out of curiosity and for the sake of it. On the other hand, science is the only enterprise that leads to real, tangible improvement in our quality of life – from providing electricity, to ensuring we can get our vasectomies while staying awake and watching the entire procedure without feeling any pain, to allowing us to have enough food to survive. So one could also argue that the goal of science is to improve the quality of life of humans (and other organisms). The clash between the two views is what this paper’s about, by looking at the views of Francis Bacon and Joseph Banks (one of the historical scientists I admire the most). Bacon wanted science to be a servant of the people, while Banks advocated a more hedonistic approach, and this paper looks at how the two views played out back then.
Powell R. 2012. The Future of Human Evolution. The British Journal for the Philosophy of Science 63, 145-175.
In the Q&A after my recent talk, I was asked whether natural selection was still acting on humans. As I am wont to do, I waffled around in my answer, but this paper is what I would have replied to the question. My reply consisted of: natural selection is always acting, even if it’s just stabilising selection; studies have shown natural selection acting on human populations, citing some study I read once about Peruvian teeth; and if you get run over by a car because you’re too stupid to look for cars, that’s natural selection acting (this last one’s not very scientifically-sound, but it did get a laugh from the audience). This paper argues perfectly about how natural selection is always acting on humans – if it weren’t, a lot of our adaptive traits would long be gone!
McNamara ME, Briggs DEG, Orr PJ, Noh H & Cao H. 2012. The original colours of fossil beetles. Proc. R. Soc. B 279, 1114-1121.
One of the themes I always bring up is how technologically-advanced palaeontology has become, because there is still a persistent stereotype of palaeontologists as bone-diggers and stamp collectors. Some undoubteably are, but palaeontology has no moved on to become a field that uses such techniques as computer tomography or biomechanics. I bring this up because one of the latest fads in palaeontology is reconstructing the colours of fossils, whether these be Archaeopteryx feathers, moth scales, or beetles, and none of these studies could even be possible without using high-tech gadgetry. This paper concerns the colouring of some fossil beetles. Beetles get their main colour not from pigments, but from nanostructures in their cuticle – it’s shaped with nano-scale steps, ridges, bumps, etc. that act to reflect and change light in such a way that it appears colourful and metallic to our eyes. This study concerns what happens to the colour diagenetically, after fossilisation – if the colour is structural, why aren’t all well-preserved beetle body fossils colourful? It turns out that in fossils, the colour is preserved by a reflective layer on the cuticle that remains preserved. During diagenesis, it gets altered in such a way as to produce a wavelength that’s on average 71.5 nm longer (+-~25), so we can roughly predict what the real colour of the beetles was. In addition, even when the layer isn’t preserved, associated microstructures are, and this will enable us to approximate the original colour.
Nicholson DJ. 2012. The concept of mechanism in biology. Studies in History and Philosophy of Science C 43, 152-163.
This paper, first of all, provides an excellent overview of the history of the concept of mechanism in biology, explaining how there are distinct meanings to the word: you either talk of philosophical mechanicism, or of machine mechanism (e.g. “the brain works like a computer”), or of causal mechanism (e.g. “the fact that the brain is a machine leads to the following conclusions about how it works”). It’s an interesting, and imo very valid paper. Even if you disagree with the different mechanisms, the historical overview itself is very interesting.
Stadler T & Steel M. 2012. Distribution of branch lengths and phylogenetic diversity under homogeneous speciation models. Journal of Theoretical Biology 297, 33-40.
My science popularisation skills are not good enough to be able to explain what this paper’s about. Sorry. I expect that anyone interested in the stuff will understand what it’s about.
Ishikawa Y, Yamamoto N, Yoshimoto M & Ito H. 2012. The Primary Brain Vesicles Revisited: Are the Three Primary Vesicles (Forebrain/Midbrain/Hindbrain) Universal in Vertebrates? Brain, Behavior and Evolution 79, 75-83.
I’m sure you’ve all heard of this idiotic pop-psychology tripe of the brain being composed of three layers: the basal reptilian brain which contains our most “base instincts”, the mammalian brain, and finally the super-dooper primate brain (or human brain, I don’t know what’s more in vogue these days). It’s complete bullshit, although at one point it did have some merit as a good hypothesis when it was first proposed by MacLean. However, we now know that it’s not only phylogenetically nonsensical (“amniotic brain” makes tons more sense, since mammals didn’t evolve out of the reptiles as the hypothesis implies), but also anatomically nonsensical. As this paper shows, brain morphogenesis is a pretty variable thing. Read it – it’s the best comparative vertebrate neuroloanatomy paper I’ve read (which isn’t saying much, I don’t do vertebrates). And it’s open access!