Washington, DC, United States

Smithsonian Institution

Washington, DC, United States

The Smithsonian Institution , established in 1846 "for the increase and diffusion of knowledge," is a group of museums and research centers administered by the United States government. Originally organized as the "United States National Museum," that name ceased to exist as an administrative entity in 1967.Termed "the nation's attic"for its eclectic holdings of 137 million items, the Institution's Washington, D.C., nucleus of nineteen museums, nine research centers, and zoo—many of them historical or architectural landmarks—is the largest such complex in the world. Additional facilities are located in Arizona, Maryland, New York City, Virginia, Panama and elsewhere, and 168 other museums are Smithsonian affiliates.The Institution's thirty million annual visitors are admitted without charge;funding comes from the Institution's own endowment, private and corporate contributions, membership dues, government support, and retail, concession and licensing revenues.Institution publications include Smithsonian and Air & Space magazines. Wikipedia.

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Slater G.J.,Smithsonian Institution
Methods in Ecology and Evolution | Year: 2013

Summary: Phylogenetic comparative methods provide a powerful way of addressing classic questions about tempo and mode of phenotypic evolution in the fossil record, such as whether mammals increased in body size diversity after the Cretaceous-Palaeogene (K-Pg) extinction. Most often, these kinds of questions are addressed in the context of variation in evolutionary rates. Shifts in the mode of phenotypic evolution provide an alternative and, in some cases, more realistic explanation for patterns of trait diversity in the fossil record, but these kinds of processes are rarely tested for. In this study, I use a time-calibrated phylogeny of living and fossil Mammaliaformes as a framework to test novel models of body size evolution derived from palaeontological theory. Specifically, I ask whether the K-Pg extinction resulted in a change in rates of body size evolution or release from a constrained adaptive zone. I found that a model comprising an Ornstein-Uhlenbeck process until the K-Pg event and a Brownian motion process from the Cenozoic onwards was the best supported model for these data. Surprisingly, results indicate a lower absolute rate of body size evolution during the Cenozoic than during the Mesozoic. This is explained by release from a stationary OU process that constrained realized disparity. Despite a lower absolute rate, body size disparity has in fact been increasing since the K-Pg event. The use of time-calibrated phylogenies of living and extinct taxa and realistic, process-based models provides unparalleled power in testing evolutionary hypotheses. However, researchers should take care to ensure that the models they use are appropriate to the question being tested and that the parameters estimated are interpreted in the context of the best fitting model. © 2013 British Ecological Society.

Potts R.,Smithsonian Institution
Quaternary Science Reviews | Year: 2013

Investigations into how climate change shaped human evolution have begun to focus on environmental dynamics, i.e., the nature and tempo of climate and landscape variability, an approach that de-emphasizes static reconstructions of early hominin habitats. The interaction among insolation cycles is especially apparent in the paleoenvironmental records of the East African Rift System, where the longest records of human evolution are preserved. However, environmental indicators such as deep-sea oxygen isotopes, terrestrial dust flux, paleosol carbon isotopes, and lake sediments do not point consistently to any simple trend or climate driver of evolutionary change. Comparison of environmental indicators cautions against an exclusive focus on any given end-member of environmental fluctuation (driest or wettest, warmest or coolest), and argues for the impact of the entire range of variability in shaping evolutionary change. A model of alternating high and low climate variability for tropical Africa further implies that specific environmental indicators reflect different aspects of East African environmental dynamics. The model may thus help reconcile some of the conflicting interpretations about the environmental drivers of hominin evolution. First and last appearances of hominin lineages, benchmark biogeographic events, and the emergence of key adaptations and capacities to alter the surroundings are consistently concentrated in the predicted longest intervals of high climate variability. The view that emerges is that important changes in stone technology, sociality, and other aspects of hominin behavior can now be understood as adaptive responses to heightened habitat instability. © 2013.

Slater G.J.,Smithsonian Institution
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

A long-standing hypothesis in adaptive radiation theory is that ecological opportunity constrains rates of phenotypic evolution, generating a burst of morphological disparity early in clade history. Empirical support for the early burst model is rare in comparative data, however. One possible reason for this lack of support is that most phylogenetic tests have focused on extant clades, neglecting information from fossil taxa. Here, I test for the expected signature of adaptive radiation using the outstanding 40-My fossil record of North American canids. Models implying time- and diversity-dependent rates of morphological evolution are strongly rejected for two ecologically important traits, body size and grinding area of the molar teeth. Instead, Ornstein-Uhlenbeck processes implying repeated, and sometimes rapid, attraction to distinct dietary adaptive peaks receive substantial support. Diversity-dependent rates of morphological evolution seem uncommon in clades, such as canids, that exhibit a pattern of replicated adaptive radiation. Instead, these clades might best be thought of as deterministic radiations in constrained Simpsonian subzones of a major adaptive zone. Support for adaptive peak models may be diagnostic of subzonal radiations. It remains to be seen whether early burst or ecological opportunity models can explain broader adaptive radiations, such as the evolution of higher taxa. © 2015, National Academy of Sciences. All rights reserved.

Smith B.D.,Smithsonian Institution
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2011

Niche construction efforts by small-scale human societies that involve 'wild' species of plants and animals are organized into a set of six general categories based on the shared characteristics of the target species and similar patterns of human management and manipulation: (i) general modification of vegetation communities, (ii) broadcast sowing of wild annuals, (iii) transplantation of perennial fruit-bearing species, (iv) in-place encouragement of economically important perennials, (v) transplantation and in-place encouragement of perennial root crops, and (vi) landscape modification to increase prey abundance in specific locations. Case study examples, mostly drawn from North America, are presented for each of the six general categories of human niche construction. These empirically documented categories of ecosystem engineering form the basis for a predictive model that outlines potential general principles and commonalities in how small-scale human societies worldwide have modified and manipulated their 'natural' landscapes throughout the Holocene. © 2011 The Royal Society.

Agency: NSF | Branch: Interagency Agreement | Program: | Phase: CROSS-EF ACTIVITIES | Award Amount: 600.00K | Year: 2016


Agency: NSF | Branch: Standard Grant | Program: | Phase: EDUCATIONAL LINKAGES | Award Amount: 430.27K | Year: 2016

This grant will continue an ongoing Research Experience for Undergraduates (REU) Program at the Harvard-Smithsonian Center for Astrophysics (CfA), in which students will carry out individual research projects in solar physics under the supervision of CfA senior staff scientists and engineers for ten weeks during the summer. The student projects involve numerical modeling, data analysis from space missions currently being supported at the CfA, such as Hinode, SDO, IRIS, Wind, and DISCOVR, or engineering projects related to solar instrumentation being built at the CfA, depending on the students interests and abilities. The target group of students consists of undergraduates in Science, Technology, Engineering and Math (STEM) disciplines, with a preference for underrepresented groups in STEM fields and students from small colleges where there are few research opportunities. The program will encourage minority student applications through contacts with other minority-serving internship programs on campus, recommendations from professional contacts at minority serving institutions, and a broad advertising campaign targeted at minority colleges and universities.

Since the projects are designed to be part of cutting edge solar physics research, student projects will frequently result in joint professional publications or presentations with their CfA mentors, providing undergraduates with valuable motivation and career development experiences. Since Solar Physics is taught at relatively few colleges and universities, this program provides an important service to the discipline. With its strong Space Weather component it has the double benefit to society of adding to our understanding of potential space hazards. Moreover, former participants of this program have reported that the exposure to professional research in a university environment has helped them to decide whether to continue their education in graduate school, and whether or not to pursue research as a profession. This site is supported by the Department of Defense in partnership with the NSF REU program.

Agency: NSF | Branch: Standard Grant | Program: | Phase: COLLABORATIVE RESEARCH | Award Amount: 296.24K | Year: 2016

The species composition and dynamics of forests worldwide are changing in response to multiple factors including deforestation, invasive species, and climate and atmospheric change. The diversity of trees in a forest controls the functioning of the ecosystem, and therefore plays a critical role in regulating forest responses to global change. This award will support two workshops - one in the US and one in China - to allow scientists to share data and discuss current understanding and future priorities for studying the change in tree biodiversity over time. The workshops will involve approximately 100 participants, 75% of whom will be graduate students, post-doctoral researchers or junior faculty. Formal international partnerships and informal scientific links will be further developed by these workshops, as well as by international scientific exchanges in which US fellows spend 1-3 months in partner institutions within China. Results of the workshops will be disseminated broadly through peer-reviewed publications, a blog, project website, and other social media outlets.

By combining the largest inventory of tree diversity and dynamics in the world with expanded datasets on species-level functional traits, phylogenies, seed production, seedling regeneration, soil microbial diversity, and tree genetics these workshops will lead to an improved understanding of the dimensions of tree diversity and their role in forest function, and thereby improve predictions of compositional, structural, and dynamic responses to global change. Two international collaborative workshops will synthesize and integrate: (i) tree functional diversity with species performance to better understand how functional traits control species performance among environments; (ii) tree functional and phylogenetic diversity to investigate controls on forest ecosystem function; (iii) tree phylogenetic and functional diversity to predict community responses to change from species performance across environments; (iv) metagenomic surveys of microbial diversity with tree functional and phylogenetic diversity to assess below-ground controls on forest diversity and function; and (v) genetic, functional and phylogenetic diversity to understand the consequences of genetic diversity for species performance. These combined activities will transform current understanding of how forests work, how they are responding to current environmental change, and their resilience in the face of future change.

Agency: NSF | Branch: Standard Grant | Program: | Phase: MID-SCALE INSTRUMENTATION | Award Amount: 6.48M | Year: 2015

The Event Horizon Telescope (EHT) project will use a global network of radio telescopes employing the sophisticated technique of Very Long Baseline Interferometry (VLBI) to resolve and image the regions near two nearby supermassive black holes. One in the center of our own Milky Way Galaxy (SgrA*, pronounced Sagittarius-A star) has a mass four million times that of our own Sun; the other, in the center of a massive galaxy 50 million light years away (known as M87), has a measured mass several billion times that of the Sun. These regions will be imaged at radio wavelengths, showing detail on the scale of the apparent black-hole diameter (Event Horizon). The study of massive black holes has many applications in astrophysics and is of great popular interest; such objects are thought to fuel the most powerful activity seen in far-distant galaxies. Supermassive black holes are extreme examples of Einsteins theory of General Relativity, but the actual mechanism by which they form remains uncertain. Because of the popularity of black holes, the numerous public outreach efforts of this project will enthrall thousands of members of the general public.

The Event Horizon Telescope includes using the recently completed, NSF-funded Atacama Large Millimeter/submillimeter Array (ALMA), as well as other large, high-precision radio telescopes worldwide. This project will support assembly of a wideband VLBI correlator to process the torrent (5 Petabytes per session) of EHT data, construction of a VLBI system at the Large Millimeter Telescope (LMT) in Mexico, and development of a robust data processing pipeline. Through these developments, the EHT will track time-variable structure at the Event Horizon of SgrA*, and search for periodic signatures of orbiting inhomogeneities in the innermost accretion flow. Observations of M87 will target study of the jet-launching region of a radio-loud AGN, to cleanly distinguish between models of jet genesis whose predictions differ markedly close to the black hole. New polarimetric EHT data will reveal Schwarzschild scale magnetic structures, providing unique constraints on accretion models, as well as General Relativistic magneto-hydrodynamical (MHD) simulations.

The Event Horizon Telescope will test General Relativity (GR) in the strong gravity limit, and as its ultimate and most fundamental prize, the EHT aims at detecting the signature of the photon orbit (and enclosed shadow) predicted by GR. In addition, while only a few sources can potentially be imaged in the innermost regions, the array has the ability to provide unique and vital time domain information with high angular resolution on the structure and magnetic fields for many other active galactic nuclei (AGN), probing a spatial region of the jet outflow which is very poorly studied with current instrumentation. These topics are all at the forefront of work in AGN physics, and the anticipated data have the potential to revolutionize our understanding of black holes and their environments and to greatly enhance our understanding of the formation and evolution of jetted sources.

Broader impacts of the work include hands-on training of students and early career scientists in radio astronomy instrumentation and mm/submm interferometry, and those mentored within this project will emerge with unique observational and hardware skills that will be invaluable in the era of ALMA. All EHT data will be made available to the astronomy community, which will maximize its broad astronomical impact across many fields and disciplines, both nationally and internationally. The project includes a public outreach effort through a Scientific American blog, a possible partnership with the Smithsonian Channel, and Center for Astrophysics traveling exhibition.

Agency: NSF | Branch: Continuing grant | Program: | Phase: Particle Astrophysics/Cosmic P | Award Amount: 400.00K | Year: 2016

Gamma-rays are the highest energy form of electromagnetic radiation. Observations of astrophysical gamma-rays serve as probes of physical conditions and processes in the most extreme environments throughout the Universe, and can be used to test fundamental physics. The Very Energetic Radiation Imaging Telescope Array System (VERITAS), located in southern Arizona, is a ground-based observatory designed to study high energy gamma-rays. VERITAS has unique capabilities, providing high sensitivity pointed observations of both galactic and extragalactic sources. This award provides funding to continue VERITAS operations. During this time the Observatory will complete a program designed to address themes in Particle Physics and Fundamental Laws, Black Holes, Cosmology, and Galactic Particle Accelerators. This award will also support the VERITAS collaboration efforts to engage the public in science. These include collaboration with the Whipple Observatory Visitors Center to promote VERITAS science to the public, other educators, museum professionals and the wider community.

VERITAS is an array of four 12-meter atmospheric-Cherenkov Telescopes. VERITAS seeks both to identify new sources of high energy gamma rays, and to perform in-depth studies of the known sources to better understand their underlying fundamental processes. The primary targets of VERITAS Galactic observations are supernova remnants, pulsars, binary systems, and sources whose classification is unknown. The extragalactic targets observed by VERITAS include active galactic nuclei, radio galaxies, starburst galaxies, galaxy clusters, globular clusters and gamma-ray bursts. In addition, Local Group galaxies, the Galactic Center and dwarf spheroidal galaxies and are targets of VERITAS observations focused on the indirect detection of cold dark matter.

Agency: NSF | Branch: Standard Grant | Program: | Phase: DISCOVERY RESEARCH K-12 | Award Amount: 1.08M | Year: 2016

The Discovery Research K-12 program (DRK-12) seeks to significantly enhance the learning and teaching of science, technology, engineering and mathematics (STEM) by preK-12 students and teachers, through research and development of innovative resources, models and tools (RMTs). Projects in the DRK-12 program build on fundamental research in STEM education and prior research and development efforts that provide theoretical and empirical justification for proposed projects. This project aligns with Alabamas College & Career-Ready Standards (CCRS) for biology in grades 9-12 relating to Unity and Diversity. These standards are based on the Next Generation Science Standards (NGSS) and go into effect during the 2016-2017 school year. Building on prior work (DRL-119468), this project will develop and test two curriculum units on the topic of evolution for high school general biology courses, with one unit focusing primarily on human case studies to teach evolution and one unit focusing primarily on case studies of evolution in other species. The two units will be compared to examine how different approaches to teaching evolution affect students and teachers. The project will also develop and field test a Cultural and Religious Sensitivity (CRS) Resource to provide teachers with strategies for creating supportive learning environments where understanding of the scientific account of evolution is aided while also acknowledging the cultural controversy associated with learning about evolution. The impacts on student and teacher outcomes of using the curriculum units and the CRS Resource will be tested in classrooms by comparing the outcomes of the human versus non-human units, and by using or not using classroom strategies from the CRS Resource.

The project will examine student and teacher outcomes of four treatment groups: 1) Curriculum Unit 1, 2) Curriculum Unit 1 with the CRS Resource, 3) Curriculum Unit 2, and 4) Curriculum Unit 2 with the CRS Resource. The research questions are: 1) In what ways does using examples of human versus non-human evolution to teach core evolutionary concepts affect understanding of, acceptance of, and motivation to learn about evolution among high school introductory biology students? 2) In what ways do using teaching strategies that focus on acknowledging the cultural controversy about evolution using a procedural neutrality approach affect high school introductory biology teachers comfort and confidence with teaching evolution? 3) In what ways does using examples of human versus non-human evolution to teach fundamental evolutionary concepts in conjunction with teaching strategies that focus on acknowledging the cultural controversy about evolution using a procedural neutrality approach affect understanding of, acceptance of, and motivation to learn about evolution among high school introductory biology students? And 4) In what ways does using examples of human versus non-human evolution to teach fundamental evolutionary concepts in conjunction with teaching strategies that focus on acknowledging the cultural controversy about evolution using a procedural neutrality approach affect high school introductory biology teachers comfort and confidence with teaching evolution? The project will use a 2 X 2 X 2 mixed factorial quasi-experimental research design to answer these questions, and will include a total of 32 teachers, 8 in each treatment group, along with approximately 800 students. Each assessment will be administered as a pretest two weeks prior to starting the curriculum unit and as a posttest immediately after completing the unit. Test scores will be the within-subjects factors, and Curriculum Unit and CRS Resource will be the between-subjects factors.

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