About me
- johnjameswilson
- Liverpool, United Kingdom
- I am interested in how we can use DNA sequences to understand biodiversity – how do we recognise species, and how are species related at taxonomic, ecological and geographic levels? My passion for biodiversity research has led me from the world’s largest natural history collection - Natural History Museum, London, where I completed my MSc, to the Biodiversity Institute of Ontario - global centre for the international Barcode of Life, as a PhD student, and to the hyper-diverse tropics of Southeast Asia. The tropics will be the first regions to experience historically unprecedented climates and this will happen within the next decade. Consequently my recent research has focussed on understanding the effects of urbanisation and climate change on tropical and subtropical biodiversity - encompassing both species richness and ecological integrity across a diversity of taxonomic groups.
Jan 25, 2012
DNA barcoding decisionary systems
Although the status of COI as a DNA barcode for animal life has been almost universally accepted, a consensus about the optimal way to achieve a species-level identification (assignment) using DNA barcoding has yet to be reached. A new paper in PLoS ONE - DNA Barcoding of Recently Diverged Species: Relative Performance of Matching Methods - follows a similar approach to that which I used in Chapter 2 of my PhD thesis - Comparison of Decisionary Systems for DNA-based Identification of Butterflies - and my colleague Kevin Kerr followed in his paper on barcoding birds, to evaluate a range of the different assignment methods (decisionary systems) available. The authors of the recent paper report that similarity-based and diagnostic methods significantly outperform tree-based methods for species-level assignment. However, I view tree-based methods as the first choice for establishing a higher-taxon assignment, a phylogenetic relationship as opposed to tokogenetic, in cases where a species-level assignment cannot be achieved (see here). I also feel that trees are useful to visualize barcode data for cases of taxonomic confusion (see here) and new species discovery.
