When is it coevolution? A reply to Morgan-Richards et al.

I recently hypothesised that some characteristics of fleshy-fruits in New Zealand could result from coevolution with wētā (Burns 2006a). Morgan-Richards et al. (2007) expand on the subject by offering some suggestions on how this hypothesis could be tested and by conducting several small field trials. In the process they argue emphatically against the hypothesis.Morgan-Richards et al. (2007) have rather strong opinions concerning the validity of the hypothesis that some New Zealand fruits are adapted for wētā dispersal. Future work might very well validate their opinion. Unfortunately, the data and logic contained in their Forum paper do not bring us any closer to the truth.     

Can whole-drawer images measure up? A reply to Johnson et al. (2013)?

Johnson et al. (2013) found that morphometric measurements of dragonfly wings taken from actual specimens and measurements taken from whole-drawer images of those specimens were equally accurate. We do not believe that their conclusions are justified by their data and analysis. Our reasons are, first, that their study was constrained in ways that restrict the generalisability of their results, but second, and of far greater significance, their statistical approach was entirely unsuited to their data and their results misled them to erroneous conclusions. We offer an alternative analysis of their data as published. Our reanalysis demonstrates, contra Johnson et al., that measurements from scanned images are not a reliable substitute for direct measurement.     

Assessing significance under the RMA ? moving forwards: a reply to Walker et al. (2008)

Walker et al. (2008) are critical of the methods used by ecologists and others with ?vested interests? to identify significant biodiversity values and provide for their protection under the Resource Management Act (1991) (RMA), particularly the use of the draft criteria proposed in Norton & Roper-Lindsay (2004). However, we believe that their criticism is flawed because of their failure to fully understand the context of the Norton?Roper-Lindsay criteria; unjustified presumptions they make about the roles of ecologists in assisting those applying for resource consents and administering the RMA; and a failure to take into account the current realities of native biodiversity conservation for those parts of New Zealand covered by the RMA. In this reply we address these issues and outline a way to move forwards in this debate.     

A novel rhythm of microcystin biosynthesis is described in the cyanobacterium Microcystis panniformis Komárek et al

The presence of microcystins (MCY) in the cyanobacteria Microcystis panniformis Komárek et al. is reported for the first time. This strain of cyanobacterium has been isolated from Barra Bonita, an eutrophicated water reservoir in S?o Paulo state, Brazil. The identification of M. panniformis was confirmed by both traditional morphological analysis and the phycocyanin intergenic spacer sequences. MCY-LR and [Asp(3)]-MCY-LR were identified in this strain after HPLC purification and extensive ESI-MS/MS analysis. Their levels in this strain were determined by HPLC and ranged from 0.25 to 2.75 and 0.08 to 0.75 fmol/cell, respectively. Analyzing the levels of MCY-LR and [Asp(3)]-MCY-LR in different times during the light:dark (L:D) cycle, it was found that levels of MCYs per cell were at least threefold as high during the day-phase than during the night-phase. This may be associated to the biological clock since prokaryotic cyanobacteria express robust circadian (daily) rhythms under the control of a timing mechanism that is independent of the cell division cycle. Our findings also showed the same pattern under light:light (L:L) cycle.     

Response to comment by Almeida et al.: free area theories for lipid bilayers--predictive or not?

Free area theories for lateral diffusion in lipid bilayers are reviewed and discussed. It has been suggested by Almeida et al. that free area theories yield quantitative predictions for lateral diffusion coefficients of lipids. We investigate the plausibility of this suggestion by first sketching what is to be expected of a quantitative theory with predictive power, and subsequently examining whether existing free area theories comply with these expectations. Our conclusion is that current free area theories for lipid bilayers are not quantitative theories with predictive power. They involve a number of adjustable parameters, all of which are not estimated independently, but derived from fitting the theory to the very data whose behavior the theory is supposed to predict. Further, the interpretation and behavior of some of the parameters are ambiguous. The best example is the so-called activation barrier, whose qualitative behavior with the cholesterol concentration in a DMPC bilayer varies depending on the experimental method used to generate the input data and the exact assumptions made to formulate the theory. Independent determination of the activation barrier from numerical simulations or experiments appears to be very difficult.     

The shrew pleads ‘not guilty’ to the mole’s murder: comment on Bennàsar et al. (2015)

The damage on the surface of a mole fossil humerus from the early Pleistocene site of Sima del Elefante (Atapuerca, Burgos, Spain) has been recently interpreted as bite marks of the extinct shrew Beremendia fissidens. The present work considers this attribution not evident, and it stresses some doubts on the feasibility of a shrew leaving bite marks on a bone using its incisors, as well as the physical and ethological inconsistencies that it would imply.