A new look at old numbers, and what it reveals about numeration

In this study, the archaic counting systems of Mesopotamia as understood through the Neolithic tokens, numerical impressions, and proto-cuneiform notations were compared to the traditional number-words and counting methods of Polynesia as understood through contemporary and historical descriptions of vocabulary and behaviors. The comparison and associated analyses capitalized on the ability to understand well-known characteristics of Uruk-period numbers like object-specific counting, polyvalence, and context-dependence through historical observations of Polynesian counting methods and numerical language, evidence unavailable for ancient numbers. Similarities between the two number systems were then used to argue that archaic Mesopotamian numbers, like those of Polynesia, were highly elaborated and would have served as cognitively efficient tools for mental calculation. Their differences also show the importance of material technologies like tokens, impressions, and notations to developing mathematics.

Context, competition, and symbiont-induced bet-hedging between Dictyostelium discoideum and Paraburkholderia

Symbiotic interactions change with environmental context. We investigated context-dependence and bet-hedging in the symbiosis between social amoeba hosts and Paraburkholderia bacteria, where the context is the abundance of host food bacteria. Paraburkholderia have been shown to harm hosts dispersed to food-rich environments, but aid hosts dispersed to food-poor environments by allowing hosts to carry food bacteria. Through measuring symbiont density and host spore production, we show that this food context matters in three other ways. First, it matters for symbionts, who suffer a greater cost from competition with food bacteria in the food-rich context. Second, it matters for host-symbiont conflict, changing how symbiont density negatively impacts host spore production. Third, data-based simulations show in some cases this context-dependence can lead to a symbiont-induced bet-hedging advantage for hosts. These results show how food context can have many consequences for the Dictyostelium-Paraburkholderia symbiosis and suggest that symbionts can induce bet-hedging in hosts.

Policies for knowledge generation in the catch-up process

Public intervention to support knowledge generation is recognized as a fundamental strategy that enables the closing the gap between latecomers and forerunners economies. Evaluations and academic studies have been conducted on a wide variety of interventions and rapidly expanded what is known about these policies instruments. However, much of the evidence report conflicting results and can lead to misunderstandings about the potential of these interventions. This article offers a systematic review and a critical discussion of what the literature has to say about the effectiveness of these instruments. It is argued that learning about the effectiveness of interventions requires a capacity to seize and interpret its effects. Specifically, two critical factors are emphasized to understand the potential of these policies, which are their sequence of implementation and the context-dependence of interventions. Since none of these issues has been investigated in-depth, some aspects are discussed to guide future evaluations.

Chemistry and Measurement: Some Philosophical Lessons

How do chemists assign numbers to chemicals properties? What do these numbers refer to? To answer these questions, we will first point out both the context-dependence of chemicals and the epistemic limitations of chemistry. We will then investigate how chemists use various procedures to stabilize measurements and how they use mixtures of samples as ‘references’ in order to determine the amount of different chemicals in a sample. This study will enable us to query how it is possible for chemists to change one factor while holding others constant at each step of the measurement procedure. This part of our work which will lead us to query the meaning of the ceteris paribus clause and the very possibility of making holistic inferences in the domain of chemistry. To conclude, we will highlight how methodological pluralism developed by chemists makes it possible for a relational type of consistency to emerge.

Modern Mendels and Organizational Adaptation

There has been recent interest in an important mechanism of intentional, designed learning efforts: random controlled trials. We situate this mechanism within an evolutionary framework and then consider some modest propositions for our Mendelian executive. RCTs tend to suffer from a lack of consideration of context dependence, and in that regard pose an interesting contrast with processes of imitation and recombination. The Mendelian executive as envisioned here goes beyond experimentation in a narrow RCT sense and plays a broader role in nurturing organizational adaptation. Three fundamental roles of the Mendelian executive are identified: encouraging adjacencies and identifying ways in which the organization can leverage its existing strengths into new possibilities, agnostic selection reflecting the challenge of selecting out less promising pathways and amplifying more promising ones, and engaging the variegated environment in which the organization operates to both enhance the set of possible adjacencies and the diversity of feedback.

Beyond demographic buffering: Context dependence in demographic strategies across animals

Temporal variation in vital rates (e.g., survival, reproduction) can decrease the long-term mean performance of a population. Species are therefore expected to evolve demographic strategies that counteract the negative effects of vital rate variation on the population growth rate. One key strategy, demographic buffering, is reflected in a low temporal variation in vital rates critical to population dynamics. However, comparative studies in plants have found little evidence for demographic buffering, and little is known about the prevalence of buffering in animal populations. Here, we used vital rate estimates from 31 natural populations of 29 animal species to assess the prevalence of demographic buffering. We modeled the degree of demographic buffering using a standard measure of correlation between the standard deviation of vital rates and the sensitivity of the population growth rate to changes in such vital rates across populations. We also accounted for the effects of life-history traits, i.e., age at first reproduction and spread of reproduction across the life cycle, on these correlation measures. We found no strong or consistent evidence of demographic buffering across the study populations. Instead, key vital rates could vary substantially depending on the specific environmental context populations experience. We suggest that it is time to look beyond concepts of demographic buffering when studying natural populations towards a stronger focus on the environmental context-dependence of vital-rate variation.