Denis Michez,  University of Mons, Belgium

Wednesday 2 April 11:00

Sir Neil Chalmers seminar room, Darwin Centre LG16 (below Attenborough studio)

Bees (Anthophila) are one of the major groups of angiosperm-pollinating insects and accordingly are widely studied in both basic and applied research, for which it is essential to have a clear understanding of their phylogeny, and evolutionary history. Direct evidence of bee evolutionary history has been hindered by a dearth of available fossils needed to determine the timing and tempo of their diversification, as well as episodes of extinction.

Copal from East Africa containing Apis mellifera

Here we assess the similarity of the forewing shape of bee fossils with extant and fossil taxa using geometric morphometrics analyses. Predictive discriminant analyses show that fossils share similar diagnostic forewing shapes with families like Apidae, Halictidae, Andrenidae and Melittidae. Their taxonomic assessments provide new information on the distribution and timing of particular bee groups like corbiculate groups, most notably the extension into North America of possible Eocene-Oligocene cooling-induced extinctions.

For additional details on attending this or other seminars see http://www.nhm.ac.uk/research-curation/seminars-events/index.htm

Friday 28 Mar, 4.30pm

Neil Chalmers Seminar Room, DC2

The Evolution of Vertebrate Reproduction

by Zerina Johanson, Department of Earth Sciences

The early history of the jawed vertebrates, and the evolutionary transition from jawless to jawed vertebrates, is recorded entirely in the fossil record. Phylogenetically, the most basal jawed vertebrates (and some of the most crownward stem gnathostomes) are the placoderms, fossil taxa ranging in age from the early Silurian to the end of the Devonian (435-360mya). As such, placoderms record the origins and evolution of a number of major jawed vertebrate morphologies. A re-examination of the superb three-dimensionally preserved placoderms recovered from the Gogo Formation (Late Devonian, Western Australia) has provided the most detailed knowledge of this group to date.

We review recent information on placoderm embryos as well as previous descriptions of the placoderm pelvic structures and reinterpret the morphology of the pelvic region, in particular the position of the pelvic fin and the relationship of the male clasper to the pelvic girdle. Claspers in placoderms and chondrichthyans develop in very different ways; in sharks, claspers develop from the pelvic fin while the claspers in placoderms develop separately, suggesting that their independent development involved a posterior extension of the ‘zone of fin competence’.

SciFri is a cross-departmental science seminar series and social event, held on the last Friday of each month. The 45 minute talks are intended to be informal, contemporary, inter-disciplinary and cover a range of fields including the latest research, curation, science policy, library & archives research, publishing, media, fieldwork and science methods.

If you have any queries please contact the organiser Julie Reynolds (julie.reynolds@nhm.ac.uk)

For additional details on attending this or other seminars see http://www.nhm.ac.uk/research-curation/seminars-events/index.html

Maria del Mar Soler Hurtado

University of Seville, Spain

Wednesday 12 of March 11:00

Sir Neil Chalmers seminar room, Darwin Centre LG16 (below Attenborough studio)

Although abundant, the Eastern Pacific octocoral fauna was considered poorly known by Bayer (1951), mainly due to the difficulty of identification and lack of taxonomic expertise.  In addition, the continuous nature of many of the morphological characters in the taxonomy of the Octocorallia has been a major problem for the systematic study of the group.  For this reason, some authors consider octocoral characters difficult to encode or to polarize, and it is necessary to implement in this family new sources of characters (in all available disciplines) to help us in the correct identification of units (species), in order to develop a more natural classification and phylogeny than that which currently exists, which is seen as clearly artificial yet still in use. In this context, the opportunity to review important collections of gorgoniid specimens deposited in museums, such as the collection available in the NHM, is for us a major step in the development and expansion of our research.  The examination of these type specimens, from a morphological and molecular point of view, will permit their comparison with newly-collected material from Ecuador, the delimitation of specific variability, the re-evaluation of the importance of morphological characters previously used, and the description of new forms where necessary.

For additional details on attending this or other seminars see http://www.nhm.ac.uk/research-curation/seminars-events/index.htm

Still image taken from a micro-CT of the rhinoceros beetle, Oryctes boas.

Thomas J. Simonsen

Department of Life Sciences, the Natural History Museum

Friday 7 March 11:00

Sir Neil Chalmers seminar room, Darwin Centre LG16 (below Attenborough studio)

Computer-aided X-ray tomography (CT scanning) has been around as a medical, industrial and scientific tool since the early 1980s. However, it was only after the arrival of scanners with sufficient resolution power (micro-CT) in the early 2000s that the technology was used in the study of non-vertebrate animals. After the first study presenting micro-CT scanning results from insects in 2002, the technology has become a state-of-the-art tool for studies into insect comparative morphology and palaeontology (in particular involving amber fossils). On the other hand, micro-CT scanning has been criticised for not yielding the same resolution as histology, nor having the same ability to distinguish between different types of tissue, partly due to low natural contrast in soft tissue and cuticle. Nevertheless, micro-CT scanning has the advantage of being much faster than traditional methods such as histology, thus allowing for much larger samples to be examined. Furthermore, the method is largely non-destructive and thus ideal for studying rare and valuable specimens. Here I will give a short introduction to micro-CT scanning in entomology and illustrate the technology's uses (and limitations) in the study of insect, focused on forensics entomology, developmental biology and taxonomy/virtual dissections.

For additional details on attending this or other seminars see http://www.nhm.ac.uk/research-curation/seminars-events/index.htm