Developing measures of purpose - platelets, calcium signaling, and model predictive control

Purpose is fundamental to our existence, from everyday aims to grand questions about life. However, animals also have goals they pursue, plants grow towards the light, and even bacteria move away from acid. Goal-directed behavior is evident in all living things. How purpose fits into nature remains a hot topic in philosophy. 

Yet whether its source is Darwinian evolution or Aristotelian final causes, the way biologists talk about purpose remains at a conceptual or narrative level. This stands in marked contrast to biological mechanisms which are addressed directly, empirically, and statistically. The reason is that we know how to test hypotheses about mechanisms. This ability has oriented modern science thoroughly towards mechanistic explanations. No similar method currently exists for purpose. 

Our goal is to create “purpose fitting”, a way of evaluating hypotheses about purpose with empirical data and statistics. This will add a new standard of statistical analysis and ultimately change attitudes about the role of purpose in biology. Our experimental program in platelet biology and hemostasis, while designed to scaffold this computational development, also has its own research goal. Our experimenters are pioneers in considering thrombi as transient tissues rather than as a collection of individual cells. 

We propose an exciting experimental program that systematically investigates how platelet communication and coordination help to protect mammals from blood loss. Finally, our scientific research was inspired by philosophy, and we will contribute a fresh perspective to its debates using our theoretical and experimental advances.