Friday, 8 July 2016

ALife day 5

ALife day 5; last but not least.

The day started as usual with a fascinating keynote: today it was Linda Smith on “We need a developmental theory of environments”. Linda’s work is on development in human babies. She has gathered a rich corpus of information on babies’ perceived environments over their first two years of life. This has been gathered from head-mounted cameras (which today are so small they are just a chip in a headband), and demonstrate convincingly that the baby’s perceived environment changes dramatically over time, and that those changes are deeply embedded in its development. Early on, there are lots of close up faces, of a few adults. Later on, the baby’s view moves to hands: watching others, and its own, manipulating objects. Different experiments demonstrate the essential nature of the body / brain / environment feedback loop.  What is in this loop changes as the baby grows, and we need to understand when and how. And, of course (unless you are purely into how to experiment on babies for fun and profit), what does this tell us about developmental artificial life? The (perceived) environment is crucial to development.

I then went to the morning technical session on Artificial Chemistries, a potential substrate for ALife. We started with a talk on a novel replicator system based on a chemistry of functional combinators, with conservation of mass. The crucial design tradeoff is not to make the underlying artificial physics so strong that replication is trivial (a “copy organism” operation in the physics), nor to make it so sparse that replication is computationally infeasible. One way to strike the happy medium is to ensure the “functional units” are composed of a few “primitive units”, giving the system a small but crucial distance from the “atoms”. Next we heard about an extension of Hutton’s original replicator AChem, adding kinetics under the Gillespie algorithm, to find a “sweet spot” where a rich set of reaction occur in a computationally feasible time. Then we heard about “messy chemistries”, those that produce a wide range of uncontrolled products, and the conditions for one of the products to come to dominate, suggesting a “selection-first” AChem route to ALife. Then we had a description of a reaction-diffusion system incorporating energetics, and how a combination of exothermic and endothermic reaction systems can stabilise temperature across a region. Finally, we heard about taking mathematics seriously in order to use algebraic concepts, particularly non-associative algebras, to design a novel sub-symbolic AChem.

Then on to the closing keynote of the conference: Katie Bentley on “Do Endothelial Cells Dream of Eclectic Shape?” She explained the title: her work is about computational modelling of real biological systems, based on computational complex systems approaches. She had been warned biologists wouldn’t read something with the word “computational” in the title, so needed to use just biological words. But she wanted to signal to the CS-types that this might be of interest to them too, so used the punning title. She asked us if we got the pun: all but one hand went up. She then asked that person if they had seen the film; yes. She told us that if this was a straight biological conference, no one would have got the pun, and hardly anyone would have seen the film. Divided communities indeed. She went on to describe her computational model of vascular growth, in normal tissue and in tumours. Agent Based modelling, combined with real data and close interactions with biologists (who know which published results to trust, and which not), have resulted in several predictions that have been tested and confirmed in the wet lab. Mostly information flows from biology to ALife; this work demonstrates a great feedback from ALife into biology.

Then it was all over bar the closing ceremony: information about the International Society for ALife, the next two ALife conferences (ECAL 2017 in Lyon, France; ALife 2018 in Japan), and a variety of awards for best papers, lifetime achievements, and contributions to the community.

A truly excellent conference, in content and in organisation. I had a wonderful time, and my head is buzzing with ideas and connections. My neural pathways have been exercised and reconfigured. I need to go home and process all this information further.

Next year in Lyon.

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