Pathogen Diversity from an Ecological Perspective

Annual Science Board Symposium and Meeting Complexity: Theory and Practice

Better Forecasting Our Ecological Future: Taming Big Data with Big Theory

Annual Science Board Symposium and Meeting Complexity: Theory and Practice

Welcome to the 2014 SFI Science Board Symposium

Annual Science Board Symposium and Meeting Complexity: Theory and Practice

Polyplexity: Complexity Science for the Social and Policy Sciences

Herbert Simon’s famous ant-on-the-beach metaphor points to the possibility of two alternative representations for the same complex phenomenon: the ant’s convoluted path on the beach may be described as complex behavior against a simple background, or as simple behavior against a complex background. Taking...

What's Science News (and What Isn't)?

SFI journalism fellow Guy Gugliotta talks about what makes a science news story, how reporters choose what they write, and how science reporters interact with scientists — what reporters need, what they get, how reporters and scientists misunderstand each other, and how the process might be streamlined...

Sandpiles and System-Spanning Avalanches

A sandpile on a graph is an integer-valued function on the vertices. It evolves according to local moves called topplings. Some sandpiles stabilize after a finite number of topplings, while others topple forever. For any sandpile s_0 if we repeatedly add a grain of sand at an independent random vertex,...

Denaturation of Circular DNA

DNA denaturation is the process by which the two strands of a DNA molecule separate. This process is essential both for biological processes such as gene transcription and for artificial processes such as PCR. A prototypical model for studying the denaturation of DNA upon heating is the Poland-Scheraga...

The Emergence of Organizations and Markets

The social sciences have sophisticated models of choice and equilibrium but little understanding of the emergence of novelty. Where do new alternatives, new organizational forms, and new types of people come from? Combining biochemical insights about the origin of life with innovative and historically...

Informational Principles in the Perception-Action Loop

Ashby's Law of Requisite Variety (1956) and, in last years, especially its later rediscovery and extension by Touchette and Lloyd (2000, 2004) have indicated that Shannon information acts as fundamental "currency" constraining the potential organization and "administration" of cognitive tasks. In particular,...

Why the Internet Won't Get You Any More Friends

Social media promises us an ever-expanding circle of friends, but that may be an empty promise. Social behavior is firmly rooted in biology, and our brains are hard-wired to maintain meaningful relationships with only about 150 people. Evolutionary psychologist Robin Dunbar formulated "Dunbar's Number"...

What’'s So Social About the Social Brain?

The social brain hypothesis was formally launched two decades ago, and the intervening period has seen a considerable amount of both comparative and neuroimaging research. While evidence in support of the quantitative predictions of the hypothesis has accumulated steadily, it has also become apparent...

Medical, Scientific, Political and Journalistic Pitfalls in the Study of Confusing Illnesses

When illnesses are confusing, without clear mechanisms or sharply-defined symptoms, they are often considered psychosomatic, and there's a consistent pattern of poor handling by federal agencies, researchers, doctors, and the media. AIDS, multiple sclerosis, chronic Lyme disease, and chronic fatigue...

A Game Approach to the Emergence of Hostile Leadership

Recent archaeological models have examined consensual paths to incipient social leadership. A modification of the Hawk-Dove game explores conditions under which non-consensual appropriation of resources is rewarded. In some circumstances such behavior is not rewarded even in the absence of sanctions....

Complex-Systems-Biology Approach to Plasticity and Robustness

Life systems generally consist of different levels with hierarchy, from molecules, cells, tissues, organisms, to ecosystem. States at each level change dynamically in time, while consistency between different levels is generally formed for a stable biosystem. Such consistency is shown to lead to general...

The Challenge of Obesity, and a Systems Approach to Solutions

Obesity has grown into a major global epidemic. Rates in the US have doubled since the 1980s, with more than two-thirds of adults now overweight (including more than one third who are obese). These trends are paralleled by rapid growth in childhood obesity, suggesting adult rates may continue to climb...

Genetic and Epigenetic Determinants of Chronic Lymphocytic Leukemia Evolution

Cancer plasticity poses one of the main challenges to achieving a cure, as the malignant cell population evolves and adapt in response to effective therapy. In this work, we applied a genomic scale tool to a large cohort of chronic lymphocytic leukemia patient samples in order to dissect the dynamics...

A Discourse on Decision Theory

In April 2010 I presented a seminar at SFI where I demonstrated that certain classic problems in economics can be resolved by methods that present an alternative to the dominant formalism of expected utilities in decision theory. Specifically, I noted that simple mathematical models of economic processes,...

Active Discovery of Network Roles for Predicting the Classes of Network Nodes

We consider a network in which we know how the nodes are connected, but we do not know the class labels of the nodes. We wish to identify the best subset of nodes to label, in order to most accurately predict the class labels of the rest of the nodes. In contrast to previous work, we do not assume that...

A Wild Solution for Climate Change

Our planet’s biology and its climate are inexorably coupled. Warmer and less predictable climates will continue to diminish the planet’s biodiversity. But biological systems can be part of a solution. Conservation biology pioneer Thomas Lovejoy will examine the present and possible future impacts of...

The Lexicon as a Dynamical System: The Drive to Keep Words Distinct and the Evolution of Phoneme Inventories

All human languages make use of small systems of signal categories, such as the sounds [p] and [b], in combination to compose meaningful lexical categories, such as the words "pat" and "bat." These perceptually contrastive, yet individually meaningless signal categories are often called phonemes. Over...