Staff & Student News
Associate Curator Rick Ree (Botany) was notified that his NSF grant proposal “Collaborative Research: Automated and community-driven synthesis of the tree of life” was recommended for funding. This is a large-scale collaboration between 10 institutions, with the goal of assembling the first comprehensive draft tree of life (for all 1.8 million named species) by collecting and synthesizing the published results of the global community of systematic biologists. In addition, the goal is to develop cyberinfrastructure (software, databases, etc.) to support continued data-sharing and collaboration among scientists, to ensure ongoing synthesis of knowledge. The total award amount is $5.76 million for the three-year project, of which $900,000 has been awarded to The Field Museum. The main website for the project, to be called the Open Tree of Life Project, is not yet online, but the group is documenting their activities here.
Research & Publications
Associate Curator Janet Voight (Zoology/Invertebrates) had a paper published in early March by the Journal of the Marine Biological Association of the United Kingdom. Her paper reports differences in the number of arm suckers in Muusoctopus hydrothermalis; a species formerly assigned to the genus Vulcanoctopus, then reclassified under Muusoctopus following a molecular study of evolution by Janet and colleagues that found that regardless of how different this species looks (fig. 1) compared to others in the genus (fig. 2), they are each other’s closest relatives. This octopus is known only from hydrothermal vents on the East Pacific Rise (see header image). Janet has previously published a report of a group of the animals feeding on swarming amphipods (Image to the left).
Octopuses of Muusoctopus hydrothermaliswere collected using the suction sampler by the DSV “Alvin” at 2495–2620 m depths on the East Pacific Rise, at 9ºN and near 13ºN. None of the many studies using molecular data have found any genetic divergence among what look like the same species of hydrothermal vent animals at these sites, and all available data, including some molecular data, indicate that the octopuses are not different. However, Janet found that octopuses from the two sites differed by about 12% in the average number of suckers on each arm. Why?
In fishes (and other vertebrates), individuals that develop as embryos in cooler temperatures often carry more characters that vary by number, such as gill filaments or vertebrae, than do individuals who developed at cooler temperatures. This pattern, first recognized by David Starr Jordon in 1891, had never been reported in any member of the Phylum Mollusca. Tests to determine whether environmental temperature during development created the difference have been essentially impossible, as no one has ever even seen an egg of this species. However, Janet looked at available environmental information on the two vent sites. Both had stunningly high temperature vents nearby, but octopuses are too smart to enter super-heated water (they don’t survive if they do). But the vent fluid at one area carried more dissolved metal than did fluid at the other. Dissolved metal binds with the poisonous sulfide ion to reduce the toxicity of the vent fluid. She hypothesized that where the fluid was less toxic, female octopuses brood their eggs at slightly higher temperatures and produce offspring with fewer suckers than they do where the vent fluids have high toxicity.
Why does this matter? Sucker counts help us tell octopus species apart. Sometimes, after preservation has removed all the color from an octopus (and made its skin look a little nasty) there aren’t a lot of characters to use. Sucker counts have been widely considered to be species-specific but this study of 13 specimens shows that the count can vary within a species, potentially due to environmental factors. The character of sucker count may not be absolute, so variation must be considered, using multiple specimens from as broad of a geographical and temperature range as possible. Second, this study indicates that perhaps Jordan’s Rule isn’t just about Fish, but applies equally well throughout the animal kingdom.
Some time ago, A. Watson Armour III Curator Bob Martin (Anthropology) was invited to write a foreword for the second, expanded edition of Alan Dixson’s very successful book Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Humans (Oxford University Press). An advance copy of the book has just landed on Bob’s desk, in advance of official publication in May. Alan Dixson, who can justifiably be described as the world’s leading expert on the comparative biology and evolution of primate reproduction, is currently a Professor in the School of Biological Sciences at Victoria University of Wellington, New Zealand. The new version of his book is almost 800 pages long, with over 2,500 references.
Hot off the press, Primate Sexuality receives the seal of approval from Alan Dixson's bulldog Huxley.
Lab Technician Erin Sackett-Hermann, DNA Educator and Researcher Erica Zahnle, and Lab Manager Kevin Feldheim (all Pritzker Lab) attended the 3rd Annual X-Gen Congress and Expo from March 5–8. This conference highlighted the use of next generation sequencing in clinical biology and genomics. Next generation sequencing is a new way to collect DNA sequence data and allows scientists to collect much more data at unprecedented rates. The conference featured speakers from The J. Craig Venter Institute, University of Chicago, Scripps Research Institute, and several biotech companies with topics ranging from epigenetics to genome assembly to how RNA functions in our cells.
Associate Curator Rick Ree (Botany) traveled to the University of Hawaii at Manoa from March 1–9, where he gave an invited seminar in the Botany Department, entitled “Inferring phylogeny from RAD sequences,” which featured the cutting-edge work of Botany Resident Graduate Students Deren Eaton and Ben Rubin. RAD is a new method for mining the entire genome of any organism for DNA sequence variation that can be used to infer evolutionary relationships. During his visit, Rick was also invited to give two lectures in a graduate course on biogeography.