Hi Jesse and Sonali,
An extremely well written essay. I enjoyed it a lot. I agree that information is the necessary link to answer a lot of these fundamental questions, and that information is physical. I would suggest reading "Information as a Physical Quantity" by Neal Anderson. I think you might enjoy that paper.
I have not quite wrapped my head around (or agree) with top down causation yet but I see it is very popular, and exploring it further will be a major takeaway from this contest. I wonder if the consciousness box in Fig.1, should have 'lower intelligence' written within in. I am not quite sure we can any consciousness without some amount of intelligence accompanying. However consciousness as form of information phase transition is something I concur with and discuss in detail with the associated math in my own submission "Intention is Physical".
"What are the theory-independent observable phenomena and informational links behind the origin of life and intelligence that a unifying framework must contain?"
I suggest some thermodynamic constraints, inspired by derivations based on the Landauer Principle to explain emergence of both learning and intelligence, as well goal directed agency in agents modeled as Markov finite state machines. Have a look if can.
Cheers and good luck.
Natesh
PS: I rated your essay, deservedly high because I think this is top-notch work. And I also got introduced to Goldenfeld and Woese's work from your references. Thanks for that.