Adaptation Is Not Just Improvement over Time.

The idea that an agent's actions can impact its actual long-term survival is a very appealing one, underlying influential treatments such as Di Paolo's (2005). However, this presents a tension with understanding the agent and environment as possessing specific objective physical microstates. More specifically, we show that such an approach leads to undesirable outcomes, for example, all organisms being maladaptive on average. We suggest that this problematic intuition of improvement over time may stem from Bayesian inference. We illustrate our arguments using a recent model of autopoietic agency in a model protocell, showing the limitations of previous approaches in this model and specific instantiations of Bayesian inference by ignorant observers in certain scenarios.

Measuring Fitness Effects of Agent-Environment Interactions.

One important sense of the term "adaptation" is the process by which an agent changes appropriately in response to new information provided by environmental stimuli. We propose a novel quantitative measure of this phenomenon, which extends a little-known definition of adaptation as "increased robustness to repeated perturbation" proposed by Klyubin (2002). Our proposed definition essentially corresponds to the average value (relative to some fitness function) of state changes that are caused by the environment (in some statistical ensemble of environments). We compute this value by comparing the agent's actual fitness with its fitness in a counterfactual world where the causal links between agent and environment are disrupted. The proposed measure is illustrated in a simple Markov chain model and also using a recent model of autopoietic agency in a simulated protocell.

Open-Ended Evolution: Perspectives from the OEE Workshop in York.

We describe the content and outcomes of the First Workshop on Open-Ended Evolution: Recent Progress and Future Milestones (OEE1), held during the ECAL 2015 conference at the University of York, UK, in July 2015. We briefly summarize the content of the workshop's talks, and identify the main themes that emerged from the open discussions. Two important conclusions from the discussions are: (1) the idea of pluralism about OEE-it seems clear that there is more than one interesting and important kind of OEE; and (2) the importance of distinguishing observable behavioral hallmarks of systems undergoing OEE from hypothesized underlying mechanisms that explain why a system exhibits those hallmarks. We summarize the different hallmarks and mechanisms discussed during the workshop, and list the specific systems that were highlighted with respect to particular hallmarks and mechanisms. We conclude by identifying some of the most important open research questions about OEE that are apparent in light of the discussions. The York workshop provides a foundation for a follow-up OEE2 workshop taking place at the ALIFE XV conference in Cancún, Mexico, in July 2016. Additional materials from the York workshop, including talk abstracts, presentation slides, and videos of each talk, are available at http://alife.org/ws/oee1 .

Complex Autocatalysis in Simple Chemistries.

Life on Earth must originally have arisen from abiotic chemistry. Since the details of this chemistry are unknown, we wish to understand, in general, which types of chemistry can lead to complex, lifelike behavior. Here we show that even very simple chemistries in the thermodynamically reversible regime can self-organize to form complex autocatalytic cycles, with the catalytic effects emerging from the network structure. We demonstrate this with a very simple but thermodynamically reasonable artificial chemistry model. By suppressing the direct reaction from reactants to products, we obtain the simplest kind of autocatalytic cycle, resulting in exponential growth. When these simple first-order cycles are prevented from forming, the system achieves superexponential growth through more complex, higher-order autocatalytic cycles. This leads to nonlinear phenomena such as oscillations and bistability, the latter of which is of particular interest regarding the origins of life.

Refusal of potentially life-saving treatment for minors: The emerging international consensus by courts.

A series of decisions by superior courts exercising their parens patriae jurisdiction in Australia, New Zealand, the United Kingdom and Canada has overturned decisions by parents, and by minors, including some close to the age of 18, to decline life-saving treatment on the basis that such treatment is "in the best interests" of the children concerned. This article reviews the reasoning in such cases and analyses the justifications proffered for giving limited weight to the expressed wishes of children and even of their parents in such matters. It identifies that the issues have particularly arisen in respect of families that are Jehovah's Witnesses and also where there is strong opposition to the application of mainstream medicine in the context of burdensome treatment for life-threatening conditions. It acknowledges the seriousness of such decisions and the potential for collateral influences that are difficult to identify to exert significant impact upon wishes expressed in respect of children who are seriously ill. It also accepts the complexities of identifying the "real wishes" of children. However, it contends that in appropriate cases flexibility in determining children's overall best interests is necessary and that the autonomy otherwise given to mature minors should play a more significant role in courts' decision-making in respect of the authorisation of treatment that children have purported to decline.

Coronial law and practice: a human rights perspective.

Coronial law and practice inevitably impact upon the human rights of those affected by deaths. It is important that such rights be incorporated in how death investigations, up to and including coronial inquests, take place. This article explores the significant impact of the jurisprudence emanating from the European Court of Human Rights, as well as the application of such law by the courts of the United Kingdom and potentially in other countries. It argues that viewing the work of coroners through the lens of human rights is a constructive approach and that, although in the coronial legislation of Australia and New Zealand, many human rights, especially those of family members, and civil liberties are explicitly protected, there remain real advantages in reflecting upon compliance with human rights by death investigation procedures and decision-making.

Evolution of associative learning in chemical networks.

Organisms that can learn about their environment and modify their behaviour appropriately during their lifetime are more likely to survive and reproduce than organisms that do not. While associative learning - the ability to detect correlated features of the environment - has been studied extensively in nervous systems, where the underlying mechanisms are reasonably well understood, mechanisms within single cells that could allow associative learning have received little attention. Here, using in silico evolution of chemical networks, we show that there exists a diversity of remarkably simple and plausible chemical solutions to the associative learning problem, the simplest of which uses only one core chemical reaction. We then asked to what extent a linear combination of chemical concentrations in the network could approximate the ideal Bayesian posterior of an environment given the stimulus history so far? This Bayesian analysis revealed the 'memory traces' of the chemical network. The implication of this paper is that there is little reason to believe that a lack of suitable phenotypic variation would prevent associative learning from evolving in cell signalling, metabolic, gene regulatory, or a mixture of these networks in cells.

Generation of tactile maps for artificial skin.

Prior research has shown that representations of retinal surfaces can be learned from the intrinsic structure of visual sensory data in neural simulations, in robots, as well as by animals. Furthermore, representations of cochlear (frequency) surfaces can be learned from auditory data in neural simulations. Advances in hardware technology have allowed the development of artificial skin for robots, realising a new sensory modality which differs in important respects from vision and audition in its sensorimotor characteristics. This provides an opportunity to further investigate ordered sensory map formation using computational tools. We show that it is possible to learn representations of non-trivial tactile surfaces, which require topologically and geometrically involved three-dimensional embeddings. Our method automatically constructs a somatotopic map corresponding to the configuration of tactile sensors on a rigid body, using only intrinsic properties of the tactile data. The additional complexities involved in processing the tactile modality require the development of a novel multi-dimensional scaling algorithm. This algorithm, ANISOMAP, extends previous methods and outperforms them, producing high-quality reconstructions of tactile surfaces in both simulation and hardware tests. In addition, the reconstruction turns out to be robust to unanticipated hardware failure.

Further results in multiset processing with neural networks.

This paper presents new experimental results on the variadic neural network (VNN) [McGregor, S. (2007). Neural network processing for multiset data. In Proceedings: Vol. 4668. Artificial neural networks - ICANN 2007, 17th international conference (pp. 460-470). Springer]. The inputs to a variadic network are an arbitrary-length list of n-tuples of real numbers, where n is fixed, and the function computed by the network is unaffected by permutation of the inputs. This paper describes improvements in the training algorithm for the variadic perceptron, based on a constructive cascade topology, and performance of the improved networks on geometric problems inspired by vector graphics. Further development may allow practical application of these or similar networks to vector graphics processing and statistical analysis.

Levels of description: a novel approach to dynamical hierarchies.

We present a novel formal interpretation of dynamical hierarchies based on information theory, in which each level is a near-state-determined system, and levels are related to one another in a partial ordering. This reformulation moves away from previous definitions, which have considered unique hierarchies of structures or objects arranged in aggregates. Instead, we consider hierarchies of dynamical systems: these are more suited to describing living systems, which are not mere aggregates, but organizations. Transformations from lower to higher levels in a hierarchy are redescriptions that lose information. There are two criteria for partial ordering. One is a state-dependence criterion enforcing predictability within a level. The second is a distinctness criterion enforcing the idea that the higher-level description must do more than just throw information away. We hope this will be a useful tool for empirical studies of both computational and physical dynamical hierarchies.