Systematics and Taxonomy

Taxonomy (describing, delimiting and naming organism) and systematics (organising taxonomic information about organisms into a logical classification) are fundamental in that they provide the framework for all comparative studies in biological sciences.

Professor David Bilton uses aquatic insects, particularly water beetles, to explore a range of fundamental and applied topics in ecology, evolution and conservation. All these studies are underpinned by sound taxonomy and in many cases well-resolved phylogenies, using this framework to describe new taxa and conduct essential revisionary studies. With more than 12,000 described species, water beetles are abundant, diverse and ecologically important organisms in almost all non-marine aquatic habitats, from water-filled tree holes to large lakes and rivers and on all continents except Antarctica. Their wide geographical and ecological range, together with their diversity, makes them ideal model organisms for studying topics as diverse as historical biogeography and the evolution of sexual conflict, themes explored in our recent review (Bilton et al. 2019). Water beetles are excellent surrogates of wider aquatic biodiversity and we have developed their use as indicators for ecological and conservation assessment in several regions. Beetles can also provide valuable information about ecological status through time, since many species are slow dispersers, restricted to ancient, semi-natural habitats. The Bilton group’s work on the taxonomy and systematics of aquatic beetles, particularly in Europe and southern Africa, underpins these studies and includes the production of identification guides and atlases summarising the ecology and distribution of individual taxa. It is clearly important to know what an organism is, and what it does, in order to use it in biomonitoring, and an approach such as ours, focussing on species-level data rather than just identifying invertebrates to families, is much more powerful in detecting changes to aquatic ecosystems in their early stages.

Fluctuating environments and climate change pose significant challenges to the survival of organisms, but some animals have evolved unusual mechanisms to survive extreme stresses. Rotifers, tardigrades (‘water bears’) and nematodes are microscopic metazoans that normally inhabit humid environments (freshwater, mosses and lichens) but which can withstand complete desiccation by entering a state of “suspended animation” (cryptobiosis) and recover completely once environmental conditions become favourable. While in this state, they can also withstand other extreme stresses like irradiation, very high/low temperatures, and vacuum. Dr Chiara Boschetti uses various methods, including bioinformatics, and molecular and cellular biology, to study the genome structure, morphology, physiology, ecology and evolution of these organisms. The identification and characterisation of the mechanisms that contribute to an enhanced ability to survive stress might facilitate development of novel biotechnological applications, for example food preservation and new vaccines. Bdelloid rotifers also have an extraordinary ability to acquire genes from other organisms (so-called horizontal gene transfer). The Boschetti lab specialises in understanding both the mechanisms and the evolutionary consequences of the acquisition and use of novel genes by bdelloids and other organisms.

Selected Publications

Aquatic Insects

Bilton DT, Ribera I, Short AEZ (2019) Water beetles as models in ecology and evolution. Annual Review of Entomology 64: 359-377.

Vasilikopoulos A, et al (Incl. Bilton, D.T.) (2019) Phylogenomics of the superfamily Dytiscoidea (Coleoptera: Adephaga) with an empirical evaluation of phylogenetic conflict and systematic error. Molecular Phylogenetics and Evolution 135: 270-285.

Bilton, D.T. & Ribera, I. (2017) A revision of Meladema diving beetles (Coleoptera, Dytiscidae), with the description of a new species from the central Mediterranean based on molecules and morphology. Zookeys 702: 45-112. 

Foster, G.N., Bilton, D.T., Hammond, M. & Nelson, B.H. (2018) Atlas of the Hydrophiloid Beetles of Britain and Ireland. Field Studies Council. 1-306.

García-Vázquez D, Bilton DT, et al. (2016) Reconstructing ancient Mediterranean crossroads in Deronectes diving beetles. Journal of Biogeography 43: 1533–1545.

Rotifers

Nowell RP,….Boschetti C, Barraclough TG (2018) Comparative genomics of bdelloid rotifers: insights from desiccating and nondesiccating species. PLoS Biol 16: e2004830.

Barbosa EGG, …., Boschetti C, Tunnacliffe A. (2016). A functional difference between native and horizontally acquired genes in bdelloid rotifers. Gene 590: 186-191.

Funding

David Bilton PI The evolution of salinity tolerance in aquatic Coleoptera. Fundación Seneca Fellowship for Susana Pallares. Euro 96,000. July 2019-June 2021.

David Bilton PI The conservation biology of Europe’s most threatened water beetles. Mohammed bin Zayed Conservation Fund. £8,200. 2016-2020.