Development

 

A key feature of many important biological processes is that they seem directional: they are not just homeostatic, but arrive at reliable destinations that involve a predictable sequence of events in space and time. Embryos are a striking example: as recognized long ago by Aristotle, embryos involve both a staggering increase in apparent order and a clear trajectory as the form of the organism develops. How might we analyze this goal-directedness more incisively?

Developmental biologists have been spectacularly successful over many decades in uncovering the molecular, cellular, and genetic underpinnings of development and have documented with increasing detail the dynamics of development through space and time. Yet stepping back to consider embryos as integrated entities, questions remain. Chief among these are the essential properties of embryos that allow them to develop in such a highly reproducible manner while also being responsive to conditions and resilient to perturbations.

Deeper insight into goal-directed processes in embryos will require interdisciplinary thinking at the interface of biology, physical/mathematical/computational sciences, and philosophy. Developing a toolkit and a shared universe of discourse to rigorously interrogate embryonic development promises to yield a fruitful set of analytical processes, or at the very least a fruitful heuristic, that can be applied to other phenomena that appear to be goal-directed. This request for projects explores the dynamics of directionality in embryos in new ways, including the following questions:

Potential Questions

• If the strong reductionist view of embryos is inadequate, then what is an embryo and what is the appropriate level – philosophically and scientifically – at which to address causation in embryos that captures their goal-directed self-organization into mature organisms?

• Embryos adopt a characteristic form, traditionally an important idea in developmental biology. How can the notion of form be articulated for the 21^st century in fresh, empirically grounded ways to more appropriately account for the goal-directed trajectories of embryos over their entire life histories?

• Embryos are “temporal ratchets”: they display progressive differentiation as they move towards the reliable target of mature form. Yet in some circumstances “time’s arrow” can be reversed. How can temporal ratcheting best be captured philosophically and scientifically, and what allows this rachet to be relaxed during injury or regeneration?

• Embryos are modular: they use a limited repertoire of gene regulatory networks (GRNs), physicochemical processes, and cellular behaviors in flexible combinations as development proceeds. What are the required features of these modules that allow them to contribute to goal-directed developmental processes? What kinds of variation in the deployment of these modules are possible, given the goal-directed nature of embryos?

• Embryos are both responsive to their environments and robust to perturbation. These phenomena reciprocally enable one other – environmental responsiveness is often remarkably robust, while robust development often entails plastic underlying compensatory processes. Can a more refined notion of robustness be developed in dialogue with 21^st century experimental biology?

• Seemingly unguided processes within embryos or embryo-like cell collectives nevertheless lead to precise developmental outcomes. How do exploratory processes within and among the cells of the embryo feed into robust directional development by fueling both flexibility and reliability?

• One disputed proposal is that the developmental processes that underlie items 1-6 were initially malleable but became more autonomous. How could one detect or establish whether such a directional shift occurred, and, if it did, what processes are responsible for it?

• Development is the product of an evolutionary history, but in turn shapes subsequent evolution by enabling new capacities while limiting other changes. How are goal-directed processes in embryos shaped by evolutionary forces, and, conversely how do developmental processes fuel and constrain evolutionary trajectories?

Instructions

Compelling responses to this research track will prioritize clear, bold and actionable projects. Some potential respondents may believe that their previous work has already addressed one or more of the overlapping questions posed above. Such individuals are encouraged to apply, providing they address why such answers have yet to gain broader traction within the relevant professional communities and provided that they propose what could be done to increase such traction. Successful outcomes will not only fuel increased insight but garner sufficient attention to change the status quo of thinking on these frontiers.

Submission Form

Back