Inferring the Past for Traits that Alter Speciation and Extinction

I will describe BiSSE, a likelihood-based approach to infer how speciation and extinction rates depend on the state of a particular character. The phylogenetic tree of a group of species contains information about character transitions and about diversification: higher speciation rates, for example,...

A Science of Cities

For the first time, it appears that there is enough momentum in the world to beginning to define "a science of cities" or perhaps "a science for cities." Our concern with cities over the last century has largely been based on defining obvious problems and attempting to solve them without much understanding...

Systematic Biological Modeling, Model Reduction, and Prospects for Complexity-Related Understanding

Experience in biological modeling at the cellular and developmental scales has led to a systematic approach to creating and exploiting these heterogeneous and complex models. A model specification phase uses quasi-equilibrium and/or steady-state statistical mechanics of molecular complexes such as those...

The Triple Revolution: Groups to Social Networks, Personalized Internet, Mobile Access

I discuss the structural changes that have facilitated the turn to social networks. I show how digital media — the internet and mobile devices — have been both responded to and amplified the social network revolution in how people connect in the community, the household and at work.

Information Spread in Structured Populations

Given a finite, genetically homogeneous population, suppose that a single mutant in introduced. What is the probability this mutant will become fixed in the population? In 1958 the Australian statistician Patrick Moran answered this question for birth-death processes in unstructured populations. Whether...

Structural Determinants of Scoring Dynamics and Outcomes in Team Competitions

The outcomes of many team-based competitions are determined by the steady accumulation of minor interactions over time. Yet we lack a general understanding of their fundamental dynamics and how those dynamics are shaped by a competition's structure. We introduce a novel generative model that can directly...

Information-Based Physics: An Intelligent Embedded Agent's Guide to the Universe

In this talk, I propose an approach to understanding the foundations of physics by considering the optimal inferences an intelligent agent can make about the universe in which he or she is embedded. Information acts to constrain an agent’s beliefs. However, at a fundamental level, any information is...

Graph Grammars and Directed Hypergraphs: Discrete Models of Chemistry

Labeled (multi)graphs have a long tradition as models of molecules as witnessed by the field of ``chemical graph theory''. Chemical reactions, in this setting, are naturally thought of as graph transformations, a notion that goes back to the work Dugundji and Ugi. In a more convenient framework chemical...

How Social Media Might Help You Survive the Next Big Disaster

Historically, when a wildfire, earthquake or hurricane strikes, people seek information from authorities. Today, however, with every disaster event, we learn of new and accelerated ways in which people not only seek information beyond official sources, but also how they produce and share it with neighbors,...

Efficient Coordination in Weakest Link Games

Coordination problems resembling weakest-link games are ubiquitous in the economy and society. Since they possess Pareto ranked equilibria it is important to understand if and when agents are able to coordinate on the efficient equilibrium. Existing research on weakest-link games shows an overwhelming...

Darwin, Quasi-Darwianian, Pseudo-Darwinian phenomena in Cultural Evolution?

To what extent—if at all—is cultural evolution governed by “Darwinian” algorithms of natural selection? I have been a champion of the “meme’s eye” perspective on culture for several decades, and encountered huge resistance, most of it hysterical and confused, but with some serious exceptions. Work...

Shared Information — New Insights and Problems in Decomposing Information in Complex System

How can the information that a set of random variables contains about another random variable be decomposed? To what extent do different subgroups provide the same, i.e. shared or redundant, information, carry unique information or interact for the emergence of synergistic information? Recently Williams...

Exploiting the Synergy Between Micro-, Meso-, and Macro- Levels in a Complex System

Darwin's Extra Sense

Charles Darwin wrote that he wished he had worked harder at mathematics, so as to possess the "extra sense" that he felt mathematicians can bring to understanding the world. The new 45 minute documentary, “Darwin's Extra Sense”, explores how twenty-first century mathematics is bringing an extra sense...

Reconstructing the Wiring Diagrams of Earth's Biogeochemical Cycles

Life is far from thermodynamic equilibrium. Over the past decade, together with collaborators, I have been analyzing the biochemical reactions responsible for energy generation in all organisms, and we have identified a set of ~500 “core” genes which encode for the energy transduction systems on a planetary...

Information Theoretic Tools for Social Media

Information theory provides a powerful set of tools for discovering relationships among variables with minimal assumptions. Social media platforms provide a rich source of information than can include temporal, spatial, textual, and network information. What are the interesting information theoretic...

Statistical Physics of Hidden Markov Models

A Hidden Markov Model (HMM) is a Markov process observed through a noisy channel. HMMs are used extensively for modeling sequential data and have various applications in natural language processing, bioinformatics, mathematical economics, and so on. One of the main problems underlying HMMs is inferring...

Reconceptualizing Cultural Evolutionary Typologies

Typological approaches to understanding cultural evolution have been utilized, and strongly criticized, for more than a century (Sanderson 2007). Some of my own work has been a part of that long critique. But recent statistical analyses of cultural evolution suggest that there are patterns of punctuated...

The Evolution of Social Complexity in the Early Holocene: New Data and Theoretical Speculations

Over the last 20 years, we have enjoyed a wealth of new archaeological data that tests and revises our theories of the evolution of social complexity. Complexity here is defined as an increase in the number of non-kin that cooperate in the production and exchange of resources resulting in, among other...

Zoobiquity: How Jaguar Breast Cancer, Dolphin Diabetes, and Flamingo Heart Attacks will Transform Human Medicine

Dinosaurs suffered from brain cancer, arthritis, and gout. Koalas catch Chlamydia. Reindeer seek out narcotic escape in hallucinogenic mushrooms. Stallions self-harm in ways psychiatrists call “cutting” when they see it in human patients. Gorillas experience clinical depression. Non-human animals get...