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"Global history faces two seemingly opposite challenges for an inter-dependent, over-heating planet. If we are going to muster meaningful narratives about the togetherness of strangers near and far, we are going to have to be more global and get more serious about engaging other languages and other ways of telling history. Historians and their reader-citizens are also going to have to re-signify the place of local attachments and meanings. Going deeper into the stories of Others afar and Strangers at home means dispensing with the idea that global integration was like an electric circuit, bringing light to the connected. Becoming inter-dependent is not just messier than drawing a wiring diagram. It means reckoning with dimensions of networks and circuits that global historians - and possibly all narratives of cosmopolitan convergence - leave out of the story: lighting up corners of the earth leaves others in the dark.  The story of the globalists illuminates some at the expense of others, the left behind, the ones who cannot move, and those who become immobilised because the light no longer shines on them."

"The connection is so strong that, according to the World Bank, a simple measure of inequality predicts about half of the variance in murder rates between American states and between countries around the world. When inequality is high and strips large numbers of men of the usual markers of status - like a good job and the ability to support a family - matters of respect and disrespect loom disproportionately."

If you want to understand an ecosystem, look at what the species within it eat. In studying food webs-how animals and plants in a community are connected through their dietary preferences-ecologists can piece together how energy flows through an ecosystem and how stable it is to climate change and other disturbances. Studying ancient food webs can help scientists reconstruct communities of species, many long extinct, and even use those insights to figure out how modern-day communities might change in the future. There's just one problem: only some species left enough of a trace for scientists to find eons later, leaving large gaps in the fossil record-and researchers' ability to piece together the food webs from the past.

There's rarely time to write about every cool science-y story that comes our way. So this year, we're once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2020, each day from December 25 through January 5. Today: the structure of folklore can help explain how unrelated facts and false information connect into a compelling narrative framework that can then go viral as a conspiracy theory.

The introduction of the Internet rapidly enabled unprecedented global connectivity. In about two decades, communication became instantaneous, affordable, and independent of physical barriers. People, however, do not seem to be communicating with each other homogeneously. Online communication networks appear to be polarized and echo-chambers are manifesting for political1-5 and non-political6-9 reasons. Understanding the emergent structure of information flows on the Internet and its implications for the complexity of society is a challenge for scientists and technology developers. Mapping the organization of social systems is crucial for effective policy making involving ethnic groups10 as well as economic growth.11

The analysis of questionnaires often involves representing the high-dimensional responses in a low-dimensional space (e.g., PCA, MCA, or t-SNE). However questionnaire data often contains categorical variables and common statistical model assumptions rarely hold. Here we present a non-parametric approach based on Fisher Information which obtains a low-dimensional embedding of a statistical manifold (SM). The SM has deep connections with parametric statistical models and the theory of phase transitions in statistical physics. Firstly we simulate questionnaire responses based on a non-linear SM and validate our method compared to other methods. Secondly we apply our method to two empirical datasets containing largely categorical variables: an anthropological survey of rice farmers in Bali and a cohort study on health inequality in Amsterdam. Compare to previous analysis and known anthropological knowledge we conclude that our method best discriminates between different behaviours, paving the way to dimension reduction as effective as for continuous data.

The complexity of an ecological community can be distilled into a network, where diverse interactions connect species in a web of dependencies. Species interact directly with each other and indirectly through environmental effects, however to our knowledge the role of these ecosystem engineers has not been considered in ecological network models. Here we explore the dynamics of ecosystem assembly, where species colonization and extinction depends on the constraints imposed by trophic, service, and engineering dependencies. We show that our assembly model reproduces many key features of ecological systems, such as the role of generalists during assembly, realistic maximum trophic levels, and increased nestedness with mutualistic interactions. We find that ecosystem engineering has large and nonlinear effects on extinction rates. While small numbers of engineers reduce stability by increasing primary extinctions, larger numbers of engineers increase stability by reducing primary extinctions and extinction cascade magnitude. Our results suggest that ecological engineers may enhance community diversity while increasing persistence by facilitating colonization and limiting competitive exclusion.

A new study by UCLA professors offers a new way to understand how unfounded conspiracy theories emerge online. The research, which combines sophisticated artificial intelligence and a deep knowledge of how folklore is structured, explains how unrelated facts and false information can connect into a narrative framework that would quickly fall apart if some of those elements are taken out of the mix.