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Found 5,166 Resources

Solidarity / Diversity / Innovation

National Museum of American History

Diversity in Tropical Forests

Smithsonian Libraries

Forest Canopies, Animal Diversity

Smithsonian Libraries

Ecosystem diversity panel report

Smithsonian Libraries
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Macroevolution: Dynamics of Diversity

Smithsonian Libraries
Summary The fossil record typically exhibits very dynamic patterns of innovation, diversification and extinction. In contrast, molecular phylogenies suggest smoother patterns of evolutionary change. Several new studies reconcile this difference and reveal more about the mechanisms behind macroevolutionary change.

Preserving Plant Genomic Diversity

National Museum of Natural History
All this work can’t be done without a team! Vicki Funk (right), is a research scientist in the Smithsonian Institution’s Department of Botany and the convener of this effort. The main collectors are two Smithsonian undergraduate interns from the University of Delaware, Kristen Van Neste (second from L) and Sarah...

Global Diversity of Sponges (Porifera)

Smithsonian Libraries
With the completion of a single unified classification, the Systema Porifera (SP) and subsequent development of an online species database, the World Porifera Database (WPD), we are now equipped to provide a first comprehensive picture of the global biodiversity of the Porifera. An introductory overview of the four classes of the Porifera is followed by a description of the structure of our main source of data for this paper, the WPD. From this we extracted numbers of all 'known' sponges to date: the number of valid Recent sponges is established at 8,553, with the vast majority, 83%, belonging to the class Demospongiae. We also mapped for the first time the species richness of a comprehensive set of marine ecoregions of the world, data also extracted from the WPD. Perhaps not surprisingly, these distributions appear to show a strong bias towards collection and taxonomy efforts. Only when species richness is accumulated into large marine realms does a pattern emerge that is also recognized in many other marine animal groups: high numbers in tropical regions, lesser numbers in the colder parts of the world oceans. Preliminary similarity analysis of a matrix of species and marine ecoregions extracted from the WPD failed to yield a consistent hierarchical pattern of ecoregions into marine provinces. Global sponge diversity information is mostly generated in regional projects and resources: results obtained demonstrate that regional approaches to analytical biogeography are at present more likely to achieve insights into the biogeographic history of sponges than a global perspective, which appears currently too ambitious. We also review information on invasive sponges that might well have some influence on distribution patterns of the future.

STRI Census of Biological Diversity

Smithsonian Archives - History Div
Featured in the "Torch," February 1989

A project participant uses calipers to measure a tree on Barro Colorado Island during Smithsonian Tropical Research Institute census, similar to the one in Malaysia, on the biological diversity of tropical rain forests.

New Dazzling Diversity Exhibition Open Now!

Smithsonian Libraries
This post was written by Abigail Espiritu, a summer intern focusing on social media and the Libraries’ blog. This fall, Abigail will be entering her freshmen year at the University more »

Species diversity in local neutral communities

Smithsonian Libraries
We extend the neutral theory of macroecology by deriving biodiversity models (relative species abundance and species-area relationships) in a local community-metacommunity system in which the local community is embedded within the metacommunity. We first demonstrate that the local species diversity patterns converge to that of the metacommunity as the size (scale) of the embedded local community increases. This result shows that in continuous landscapes no sharp boundaries dividing the communities at the two scales exist; they are an artificial distinction made by the current spatially implicit neutral theory. Second, we remove the artificial restriction that speciation cannot occur in a local community, even if the effects of local speciation are small. Third, we introduce stochasticity into the immigration rate, previously treated as constant, and demonstrate that local species diversity is a function not only of the mean but also of the variance in immigration rate. High variance in immigration rates reduces species diversity in local communities. Finally, we show that a simple relationship exists between the fundamental diversity parameter of neutral theory and Simpson's index for local communities. Derivation of this relationship extends recent work on diversity indices and provides a means of evaluating the effect of immigration on estimates of the fundamental diversity parameter derived from relative species abundance data on local communities.

How does pedogenesis drive plant diversity?

Smithsonian Libraries
Some of the most species-rich plant communities occur on ancient, strongly weathered soils, whereas those on recently developed soils tend to be less diverse. Mechanisms underlying this well-known pattern, however, remain unresolved. Here, we present a conceptual model describing alternative mechanisms by which pedogenesis (the process of soil formation) might drive plant diversity. We suggest that long-term soil chronosequences offer great, yet largely untapped, potential as 'natural experiments' to determine edaphic controls over plant diversity. Finally, we discuss how our conceptual model can be evaluated quantitatively using structural equation modeling to advance multivariate theories about the determinants of local plant diversity. This should help us to understand broader-scale diversity patterns, such as the latitudinal gradient of plant diversity.

Heliconius butterfly genome explains wing pattern diversity

Smithsonian Insider

More than 70 scientists from 9 institutions including the Smithsonian Tropical Research Institute, sequenced the entire genome of the butterfly genus Heliconius, a brightly colored favorite of collectors and scientists since the Victorian era.

The post Heliconius butterfly genome explains wing pattern diversity appeared first on Smithsonian Insider.

Using Integrative Taxonomy to Disentangle Lichen Diversity

National Museum of Natural History
What are lichens? How diverse are they? Manuela Dal Forno discusses this unique group of composite organisms.
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