The Meanings of Convergence

Exploring the Implications of Biological Convergence for a Deeper Understanding of Life and its History

Evolutionary convergence describes the phenomena that occur when unrelated organisms evolve similar adaptations to similar environmental or selective pressures, arriving there by very different routes. Hundreds of examples of convergence have been documented (see, for example, http://mapoflife.org/). Many technical questions arise in this work – not least being able to distinguish, in any specific example, convergent evolution from other evolutionary processes like secondary loss, or among different kinds of convergence such as parallelisms. However, enough has been learned in recent years to make it worth raising again the broader questions of what the fact of convergence (when it is a fact) implies about the nature and processes of life.

With this initiative the John Templeton Foundation is launching a $5 million initiative which invites proposals for up to three years* supporting research on the significance of biological convergence for a better understanding of the living world. This would include (for example) philosophical investigation of some aspect of convergence, of the phenomenon itself in light of current models of biological process, or investigation of the history of its study with an eye toward clarification of the concept, its use, and meanings. Alternatively you may wish to propose empirical, synthetic, or simulation studies, or pilots for larger-scale empirical projects. Applicants may propose projects involving convergent evolution at any “level” (chemical, organ etc). However, we encourage use of biological contexts generally accepted as true examples of convergence, or which you are confident you can demonstrate to be so, since research on its meanings is likely to be sufficiently contentious without this added concern. In general we recommend requests no larger than $200,000 for conceptual and pilot projects. Most empirical projects will be under $1 million. However, we welcome conversations concerning possible exceptions.

We are particularly interested in research and scholarship that has the potential of offering insight into one or more of the following questions:

1. Does convergence at different levels point to a singular phenomenon, or are these processes in fact fundamentally different? Much research in the field seems to assume that convergence is the same phenomenon whether one is studying proteins or the camera eye. Is that correct? And what are the implications of the answer?
2. Does the phenomenon of convergence, or specific aspects of it, provide us with a different or novel way of classifying basic elements of living systems, and of understanding how those elements emerge? If so, are structural features of living systems (for example) more likely to converge than functional elements (which might be more variable due to selection history). Could convergence help us tell the difference?
3. What is the distribution of convergence and parallelism in phylogenies? Why do some groups show rampant convergence (e.g. C4 photosynthesis)? Why are at least some convergences (e.g. nitrogen fixation) clustered? What can these patterns tell us about the evolutionary process and even the nature of life more broadly?
4. What insights might be gained instead from examples of absent convergent forms; for example all major groups of land animals have evolved eel-like swimming morphology — except the mammals. Here we might ask not just why so much convergence on this form, but turn it around and ask why not mammals too?
5. Does the apparent fact that convergence has been so common in evolutionary history help us better understand in what ways and under what circumstances the evolutionary process can be described as either random or non-random?
6. What are the implications of the fact that convergence is so common for our understanding of causation, for a deeper understanding of reality?

*For grants made outside the US, or otherwise under expenditure responsibility, the maximum grant length is 33 months.