Mike Steel, Wim Hordijk, Stuart A. Kauffman

Journal of Theoretical Biology

 

A feature of human creativity is the ability to take a subset of existing items (e.g. objects, ideas, or techniques) and combine them in various ways to give rise to new items, which, in turn, fuel further growth. Occasionally, some of these items may also disappear (extinction). We model this process by a simple stochastic birth–death model, with non-linear combinatorial terms in the growth coefficients to capture the propensity of subsets of items to give rise to new items. In its simplest form, this model involves just two parameters (P, α). This process exhibits a characteristic ‘hockey-stick’ behaviour: a long period of relatively little growth followed by a relatively sudden ‘explosive’ increase. We provide exact expressions for the mean and variance of this time to explosion and compare the results with simulations. We then generalise our results to allow for more general parameter assignments, and consider possible applications to data involving human productivity and creativity.

 

Source: www.sciencedirect.com

How could Earth’s changing climate impact socioeconomic systems across the world in the next three decades? A yearlong, cross-disciplinary research effort at McKinsey & Company provides some answers.

Source: www.mckinsey.com

Stories have the power to shape our identities and worldviews. They can be factual or fictional, text-based or visual and can take many forms—from novels and non-fiction to conspiracy theories, rumors and disinformation. This Collection includes primary research papers that propose innovative, data-driven approaches to understanding stories and their impact, on such topics as the nature of narrative and narrative thinking, methods to extract stories from datasets and datasets from stories, the role of narrative in science communication, and the transformative power of stories.

Source: collections.plos.org

Nazanin Alipourfard, Buddhika Nettasinghe, Andrés Abeliuk, Vikram Krishnamurthy & Kristina Lerman 
Nature Communications volume 11, Article number: 707 (2020)

 

Social networks shape perceptions by exposing people to the actions and opinions of their peers. However, the perceived popularity of a trait or an opinion may be very different from its actual popularity. We attribute this perception bias to friendship paradox and identify conditions under which it appears. We validate the findings empirically using Twitter data. Within posts made by users in our sample, we identify topics that appear more often within users’ social feeds than they do globally among all posts. We also present a polling algorithm that leverages the friendship paradox to obtain a statistically efficient estimate of a topic’s global prevalence from biased individual perceptions. We characterize the polling estimate and validate it through synthetic polling experiments on Twitter data. Our paper elucidates the non-intuitive ways in which the structure of directed networks can distort perceptions and presents approaches to mitigate this bias.

Source: www.nature.com

Mariano Bizzarri, Douglas E. Brash, James Briscoe, Verônica A. Grieneisen, Claudio D. Stern & Michael Levin 
Nature Reviews Molecular Cell Biology volume 20, pages261–262(2019)

 

What does it mean to say that event X caused outcome Y in biology? Explaining the causal structure underlying the dynamic function of living systems is a central goal of biology. Transformative advances in regenerative medicine and synthetic bioengineering will require efficient strategies to cause desired system-level outcomes. We present a perspective on the need to move beyond the classical ‘necessary and sufficient’ approach to biological causality.

Source: www.nature.com