Mutation Size Optimizes Speciation in an Evolutionary Model

The role of mutation rate in optimizing key features of evolutionary dynamics has recently been investigated in various computational models. Here, we address the related question of how maximum mutation size affects the formation of species in a simple computational evolutionary model. We find that the number of species is maximized for intermediate values of a mutation size parameter μ; the result is observed for evolving organisms on a randomly changing landscape as well as in a version of the model where negative feedback exists between the local population size and the fitness provided by the landscape. The same result is observed for various distributions of mutation values within the limits set by μ. When organisms with various values of μ compete against each other, those with intermediate μ values are found to survive. The surviving values of μ from these competition simulations, however, do not necessarily coincide with the values that maximize the number of species. These results suggest that various complex factors are involved in determining optimal mutation parameters for any population, and may also suggest approaches for building a computational bridge between the (micro) dynamics of mutations at the level of individual organisms and (macro) evolutionary dynamics at the species level

Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions

The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions

How sharing can contribute to more sustainable cities

\ua9 2017 by the authors. Recently, much of the literature on sharing in cities has focused on the sharing economy, in which people use online platforms to share underutilized assets in the marketplace. This view of sharing is too narrow for cities, as it neglects the myriad of ways, reasons, and scales in which citizens share in urban environments. Research presented here by the Liveable Cities team in the form of participant workshops in Lancaster and Birmingham, UK, suggests that a broader approach to understanding sharing in cities is essential. The research also highlighted tools and methods that may be used to help to identify sharing in communities. The paper ends with advice to city stakeholders, such as policymakers, urban planners, and urban designers, who are considering how to enhance sustainability in cities through sharing

Evolution of Bow-Tie Architectures in Biology

Bow-tie or hourglass structure is a common architectural feature found in many biological systems. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signaling pathways to regulate multiple output genes. Little is known, however, about how bow-tie architectures evolve. Here, we address the evolution of bow-tie architectures using simulations of multi-layered systems evolving to fulfill a given input-output goal. We find that bow-ties spontaneously evolve when the information in the evolutionary goal can be compressed. Mathematically speaking, bow-ties evolve when the rank of the input-output matrix describing the evolutionary goal is deficient. The maximal compression possible (the rank of the goal) determines the size of the narrowest part of the network—that is the bow-tie. A further requirement is that a process is active to reduce the number of links in the network, such as product-rule mutations, otherwise a non-bow-tie solution is found in the evolutionary simulations. This offers a mechanism to understand a common architectural principle of biological systems, and a way to quantitate the effective rank of the goals under which they evolved.clos

PDO opperdoezer potatoes in the Netherlands

The Opperdoezer Ronde is a potato variety that was first grown in 1860 in the village of Opperdoes in the province of North-Holland in the Netherlands. In 1996 the Opperdoezer Ronde became a PDO protected product that can only be grown on 450 ha of farmland in Opperdoes every 3 years in the crop rotation. The Opperdoezer Ronde is an early potato, i.e. it has a short growing season of 10–12 weeks, from May till September. The Opperdoezer Ronde is sold at a substantially higher price than regular potatoes while intermediate costs of production are only slightly higher. This leads to a substantially higher value added per ha. The product is marketed via one company that sells the potatoes to mainly large retailers in the Netherlands. However, a maximum of one third of the production can be sold directly by the farmers to end consumers. The environmental impact per hectare of Opperdoezer Ronde is somewhat lower than for reference potatoes due to the shorter growing season. However, it becomes higher on a per ton basis due to the lower yield while it is lower per euro value added due to the high price of the Opperdoezer Ronde. The data to assess the social impact of Opperdoezer Ronde could not be accessed. However, this impact is likely negligible given the small number of producers and the absence of processing. Moreover, farmers have alternative production and employment possibilities. There might be some small impact on tourism as the village of Opperdoes has become more well-known because of the Opperdoezer Ronde.</p

Traditional family and women's condition: The reciprocal perception of Turkish and Italians

Community psychology considers gender as a central organizing category for understanding power imbalances and directing social change. The geopolitical events of these last years are heightening the contraposition between Islamic and Western countries with significant effects on ethnic prejudices, including the perception of gender roles and women’s condition. The present study focused on two different Mediterranean countries, an Islamic and Eastern one, i.e., Turkey, and a Catholic and Western one, i.e., Italy. It aimed at investigating the reciprocal perception concerning family and the women’s condition in the two states. Participants were 400 university students, both Turkish (N=199) and Italians (N=201). We performed 2 (Italian vs. Turkish) x 2 (Italy vs. Turkey) mixed ANOVAs for repeated measures testing the significance of the differences between rater countries and rated countries. Findings demonstrated an interesting “mirror effect”: Turkish and Italians perceived their home country in similar way, and similarly different from the country of comparison. Implications are discussed.