Marshal Hedin Contact:
Professor, Department of Biology
San Diego State University
Life Sciences North Room 204E
Marshal Hedin Flickr Photos
The anchor persons don’t seem particularly enthusiastic about arachnids, but hey, how often do harvestmen make the news!! :) Video here
Thanks to Mike Price for this write-up on Hedin lab happenings ….
Research effort of PhD student Shahan Derkarabetian just published in PLoS One, entitled “Integrative taxonomy and species delimitation in harvestmen: A revision of the western North American genus Sclerobunus (Opiliones: Laniatores: Travunioidea)“, PLoS ONE 9(8): e104982. In my opinion, a superb example of modern taxonomy, using multiple lines of evidence to delimit species using objective criteria, and “finishing the job” by describing emergent species. This paper serves as a template (ample data, sophisticated analyses, digitally-rich species descriptions) for our continuing revisionary research on other travunioid harvestmen.
Our research on spider phylogenomics, led by the Bond Lab at Auburn University, was just published in Current Biology. We used transcriptomes for about 40 spider families to mine orthologous genes, then conducted a battery of phylogenetic analyses on these very large molecular matrices. The biggest surprise is the non-monophyly of orb-weaving spiders – cribellate orb-weavers (e.g., Uloborus, etc) are not sister to ecribellate orb-weavers (e.g., araneids, etc). This result suggests that orb webs evolved early in spider evolution, but have been subsequently lost in a majority of derived lineages.
Non-model genomics enabled by next-generation sequencing is rapidly impacting arachnology …. I can’t wait to see what happens over the next few years!
Several members of the Hedin lab recently traveled to Newark OH to attend the 2014 American Arachnological Society meetings. Thanks to Andy Roberts for hosting a very nice meetings – superbly-organized, many great talks.
Master’s students Dave, Kristen & Angela all gave excellent talks – thanks guys for your hard work and preparation! Despite tough competition, Kristen was able to win First Place in the Student Talk competition! Kristen seemed quite surprised, but I wasn’t – she gave a very calm, precise, data-rich presentation.
I gave a talk on multilocus species delimitation in TX cave Cicurina, results from research recently funded by the US Fish & Wildlife Service. Currently working on the manuscript, so stay-tuned for this interesting story!
After the meetings I traveled through southern OH, western WV, and eastern KY collecting Laniatores harvestmen. Check out my Flickr stream to see photos from that reasonably-successful trip (bottom of Appalachians set).
I’m thankful to the National Science Foundation for recent funding of a grant proposal to conduct species delimitation research on Laniatores harvestmen. Here’s a somewhat technical synopsis:
Within the species-rich Laniatores (Opiliones= harvestmen), phylogenetic data supports an early-diverging Travunioidea, which includes Holarctic taxa from east Asia, North America, and southern Europe. This clade currently includes 45 species in 24 genera, but available evidence indicates that a large number of species remain undescribed. Travunioids are short-range endemic (SRE) taxa – small-bodied, habitat-specialized, and dispersal-limited – most travunioid species have very small geographic distributions, thus warranting conservation attention. Our research will address three primary Objectives: I) We will utilize NGS-based sequence data in multilocus species delimitation and species tree inference. II) We will combine extensive field and museum work with integrative taxonomic methods to discover and describe new species in seven primary travunioid clades. Multilocus phylogenetic data will be combined with the study of morphology for species delimitation. III) We will use travunioid datasets to empirically compare methods of multilocus species delimitation, with particular emphasis on the variables of geographic sampling and extreme population genetic structuring.
The grant will serve to train one postdoctoral researcher, one PhD student, and at least one undergraduate student. Trainees will work with PI Hedin and two of the most prominent harvestmen researchers in the world, including Dr. Nobuo Tsurusaki (Tottori University, Japan) and Darrell Ubick (California Academy of Sciences) – this training represents a tremendous opportunity to transfer taxonomic knowledge across generations. We will also build Web resources to help interested persons learn more about these animals, and Hedin will host a Harvestmen Workshop in the mountains of North Carolina, Summer 2015.
Time to get busy …