The complexity and scale of global urban development over the next quarter of a century will demand radically new approaches in development towards global sustainability (Elmqvist et al. 2018). The world’s urban population has grown from about 200 million in 1900 to 3.9 billion in 2014 and will likely reach 6.4 billion people in 2050. Over the decades to come, rapid urbanization will therefore continue, particularly in Asia and Africa. In the mid-century, 65% of populations in developing countries and nearly 90% in the developed world will live in urban areas (United Nations 2014). Cities all over the world are even now experiencing multiple impacts from global environmental change, especially climate change and land degradation, and the degree to which they must cope with and adapt to these challenges will continue to increase. While traditional, narrowly focused, planned/engineered design strategies are clearly needed to avert or mitigate such impacts in certain well-defined contexts, they are unlikely to be able to meet the full social, environmental and economic goals of cities, most notably the need for healthy, sustainable urban environments (e.g. Sustainable Development Goal 11). Strong path dependency often dominates urban development, and investments in urban infrastructure designed to fulfill one function may frequently create lock-in situations that persist over decades or even centuries. We argue that a multidisciplinary, complex systems approach, inspired by evolutionary theory, can inform the strategic design of policies and interventions to deal with challenges of growing urban regions and uncertainties in various scenarios in reducing undesirable path dependencies. Such an approach would guide the design of new (and redesign of existing) urban structures, while promoting innovative integration of grey, green and blue infrastructure in service of environmental and health objectives. Moreover, it would contribute to more flexible, effective policies for urban management and the use of urban space.
In a landmark 1977 article, Nobel laureate François Jacob made note of the highly flexible, opportunistic character of evolutionary progress, which he labeled “tinkering” (Jacob 1977). Evolutionary tinkering involves the modification and molding of existing traits and forms, which occasionally results in dramatic shifts in function in the context of changing conditions. This contrast greatly with conventional engineering and design approaches that apply tailor-made materials and tools to achieve well-defined functions that are specified a priori.
Here, we explore the idea of Urban Tinkering as the application of this evolutionary approach to urban design, engineering, management and governance. We define urban tinkering as:
“a mode of operation, encompassing policy, planning and management processes, that seeks to transform the use of existing and design of new urban systems in ways that diversify their functions, anticipate new uses and enhance adaptability, to better meet the social, economic and ecological needs of cities under conditions of deep uncertainty about the future.”
We see the discourse around evolutionary tinkering as a source of inspiration on how to navigate an urban future dominated by deep uncertainty, complexity and non-linearity. The tempo and intensity of climate changes are not known, and a flexible approach to urban design must be entertained. In this sense, admitting to our ignorance of future conditions may be the most intelligent design assumption. Urban tinkering is relevant not only to the design and planning of future infrastructure, but also to management and use of existing and planned urban spaces/structures. With new understanding of the values of ecological services in cities (Elmqvist et al. 2015), there is growing interest in increasing the links among ecological structure and other layers of urban design. To achieve the latter, approaches that encourage repurposing, experimentation, and innovative usage of existing elements are key. If well designed, an urban tinkering approach may help to reduce costly lock-in situations by incorporating infrastructure with an inherent potential to change function where needed or desired (Table 1).
Linkages between evolutionary theory and the built environment are far from new. Indeed, new understandings of adaptation in evolution have at times been inspired by observation of the built environment, architecture and design—the opposite of the relationship considered here. For example, in their highly influential paper “The spandrels of San Marco and the Panglossian paradigm,” Gould and Lewontin (1979) discussed how views of adaptation in evolutionary theory could be informed by insights into architecture and design, elaborating, in particular, on the ornamentation of spandrels—the tapering triangular spaces formed by the intersection of two rounded arches at right angles. Spandrels are the necessary architectural by-products of mounting a dome on rounded arches. In many buildings, such as the Cathedral of San Marco in Venice, Italy, they are occupied by exquisite paintings and illustrations, as elegantly described by Lewontin and Gould. The analogy here is that the spandrels were not designed de novo as a space for paintings and illustrations, but were a by-product with no specific function, later used to fulfill other functions. Similarly, in evolution, Lewontin and Gould argued that many organismal traits for which we try to ascribe an adaptive explanation may in fact have no adaptive value, or maybe secondarily modified (but see critical discussion in Queller 1995).
Theoretical linkages between the built environment and evolutionary theory are thus long-standing, and not only restricted to the natural sciences. Such approaches have been adopted in social sciences and engineering; for example, in accounting for technological change and the dynamics inherent in any social process (e.g. Dosi and Nelson 1994), or in understanding the patterns and processes of urban environmental change (Bai and Imura 2000). Specific applications often highlight the need for flexible policies and governance systems which facilitate bottom-up innovation (Kronenberg and Winkler 2009). Naturally, evolutionary approaches are also characteristic of analyses of social–ecological systems which explicitly assume co-evolution and mutual dependence of social and ecological components. The shift in thinking (with respect to dominant paradigms) needed to implement such approaches implies the need for a concomitant shift in the values of key actors and those of society at large.
We emphasize that the use of evolutionary insights in this paper is but a lens. We acknowledge the many obvious differences between urban development and evolving biological systems, such as the effects of human foresight and anticipation, innovation, and dissemination of ideas over large spatial scales. Such features may help to reduce the high transaction costs often observed in evolution in biological systems (i.e., high rates of extinction). This is not to suggest that tinkering emphasizes the economic efficiency central to dominant neo-liberal economic paradigms. Quite the opposite: tinkering allows for redundancy, diversity and complexity, and emphasizes precautionary repair and replacement, all of which favor the efficient functioning of a system as a whole, but not necessarily its individual processes. Indeed, the efficiency of a given social or economic process must be considered in the context of other processes necessary to its execution, and more generally, with respect to the functioning of the whole system.
The definition of urban tinkering adopted here relates closely to concepts already familiar in urban development, e.g., urban sustainability experiments and transitions, urban system innovations, adaptive management, ecosystem-based adaptation to climate change, nature-based solutions, and urban experimental labs (see e.g. Elmqvist et al. 2018; Bai et al. 2010). Urban tinkering may also be viewed as a conceptual cousin to “urban acupuncture” (Lerner 2014), “tactical urbanism” (Garcia and Lydon 2015) and similar ideas.
In our interpretation, however, tinkering includes some dimensions not captured by these other concepts; in particular, it explicitly stresses a social–ecological–technological complex systems perspective on the multi-functionality of new and existing urban structures, developed through collaborative engagement and analysis with a range of actors. Although urban tinkering in some ways resembles a combination of adaptive management and adaptive governance, it adds an important proactive dimension, anticipation, to these more reactive approaches. In addition, tinkering implies a dimension of curiosity and playfulness in experimentation and repurposing urban systems often lacking in other approaches (Table 1 and examples in “Box 1”).