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Fields of study
Avian phylogenetics and sytematics
Research interests
My research interests are, admittedly, quite diffuse, and bridge the fields of population genetics (population genetic structure/connectivity; effective population size; coalescent theory; etc.) and phylogenetics (model-based phylogenetic reconstruction; model selection/sensitivity; phylogenetic dating; rate heterogeneity; data partitioning; etc.). The common link among these subjects is that they are all require analytically intensive approaches (MCMCMC; genetic algorithms; parametric bootstrapping; maximum likelihood and Bayesian probabilistic approaches; etc.). From my tenure as a graduate student it has become apparent that I am at least as interested in the validity and mechanics of the analytical process as I am with the actual biological question at hand. I am therefore currently working on a number of varied projects with equally varied collaborators.
Academic background
I earned B.S. degrees in Biochemistry and Biology from Queen's University (Kingston, Ontario). I stayed on at Queen's for my M.S. (Biology) degree with Drs. Tim Birt and Vicki Friesen. Thesis Title: Appraisal of the consequences of the DDT-induced bottleneck on the level and distribution of neutral genetic variation in Canadian peregrine falcons, Falco peregrinus.
Advisors
David P. Mindell, Robert B. Payne
Brown's home page
Museum of Zoology, Bird Division Website
News
A boost for species conservation
The black ratsnake and the Blanding's turtle, two species of conservation concern in Canada, were the focus of research published online May 18, 2008 in Conservation Genetics. EEB graduate student Joseph Brown was a collaborator. The findings show how sophisticated analysis of population genetic data can be used to identify patterns of gene flow (the transfer of genes from one population to another) over different time scales and thus demonstrate how population dynamics can vary over time, possibly due to human influences. Such information can be used by conservation practitioners to better understand the dynamics required to maintain geographically separated populations of the same species. (read the article)
Most outstanding publication
Joseph Brown was awarded the 2008 Most Outstanding Publication for “Strong mitochondrial DNA support for a Cretaceous origin of modern avian lineages.” The paper was published in the journal BMC Biology 6:6.
Every year one graduate student paper is selected based on approach of study, scope of findings, and insights into questions of broad scientific interest using multiple lines of evidence. The prize is $500.
Birds and dinosaurs cavorted
A new analysis by first author Joseph Brown, graduate student, Professor David Mindell and others, offers the strongest molecular evidence yet for a Cretaceous origin of modern birds, suggesting that they arose more than 100 million years ago, not 60 million years ago, as fossils suggest. The research was published online Jan. 28 in the journal BMC Biology. The story has been widely covered; Google it.
NY Times cites EEB research: Rethinking history of birds pre- and post-dinosaur days
The research of Joseph Brown, Ph.D. student, and Professors Robert Payne and David Mindell is cited in a New York Times article March 29, 2007, in reference to their finding that more than 40 bird lineages survived the mass extinction that wiped out dinosaurs 65 million years ago.
The article titled “Mammals took their sweet time to flourish, study says” discusses research showing that most mammals, including primates, rodents and hoofed animals, began long before global extinction and survived in good shape. Brown, Payne and Mindell performed a parallel analysis of birds, which was just published in Biology Letters and referenced in Nature’s News and Views column. The studies show that the Cretaceous/Tertiary (called the K-T boundary) mass extinction had a negligible effect on the evolutionary history of vertebrates, which is a diametrically opposite view from what the fossil record shows. The fossil record implies that most modern bird and mammal lineages originated after the K-T boundary. The molecular genetic data implies that the lineages are nearly twice as old, approximately 100 million years, according to Brown, who works in Mindell's lab.
Peregrines on probation: Population’s prospects appear promising
The recently endangered peregrine falcon of North America got a health checkup of sorts and the prognosis looks good. A team of population geneticists, including first author and Ph.D. student Joseph Brown, got an unexpected result when they measured levels of DNA variation in the current cohort of falcons.
The results of their study appeared as the cover story in the January 2007 issue of the journal Molecular Ecology.
Listen to CBC Radio's interview with Brown.
U-M News Service press release
Rackham fellowship awarded
Congratulations to Joseph Brown, a second-year doctoral student in
Professor David Mindell’s lab. Brown received the 2005-2006 Rackham
International Students Fellowship, which supports outstanding international U-M students in their academic careers. Brown is one of
25 students to receive the $7,500 award this year.
Recent publications
Howes, B.J., J.W. Brown, H.L. Gibbs, T.B. Herman, S.W. Mockford, K.A. Prior and P.J. Weatherhead. 2008. Directional gene flow patterns in disjunct populations of the black ratsnake (Pantheropis obsoletus) and the Blanding’s turtle (Emydoidea blandingii). Conservation Genetics. (in press).
Brown, J.W., J.S. Rest, J. García-Moreno, M.D. Sorenson, and D.P. Mindell. 2008. Strong mitochondrial DNA support for a Cretaceous origin of modern avian lineages. BMC Biology 6:6.
Brown, J.W., P.J.vC. de Groot, T.P. Birt, G. Seutin, P.T. Boag, and V.L. Friesen. 2007. Appraisal of the consequences of the DDT-induced bottleneck on the level and geographic distribution of neutral genetic variation in Canadian peregrine falcons, Falco peregrinus. Molecular Ecology 16, 327-343.
Brown, J.W., R.B. Payne, and D.P. Mindell. 2007. Nuclear DNA does not reconcile ‘rocks’ and ‘clocks’ in Neoaves: A Comment on Ericson et al. Biology Letters, 3, 257-259.
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