Paul Francois
@pfrancois
Professor Université de Montréal, Physics of Living Systems, Machine Learning, etc…
We also tested our ideas as a generative model: give it only the terminal cell types of mouse hematopoiesis (no progenitors, no labels), and the model self organizes to recover a classical differentiation tree, with branching looking similar to known intermediate progenitors (CMP, CLP, GMP, MEP).
We can even put multiple attractors, inject cells in a global 'head' attractor, and then eventually get cascades of self-organized flips through the same mechanism
The most striking result: add local proliferation (cells dividing, like real progenitors do) and the system spontaneously self-organizes toward a flip bifurcation, the exact geometry seen repeatedly in real cell fate decisions ! we get a shallow 'head' attractor, again consistent with experiments
Now the truly new and exciting part, especially for biology. Using catastrophe theory, for a 3-state system, we track the system's motion through "bifurcation space" recovering the elliptic umbilic catastrophe along the way. Remarkably, occupancies of states define control parameters
Same mechanism, applied to MNIST digits as "phenotypes": units differentiate into a branching tree structure, echoing the classifier dynamics from our 2024 paper, but now derived from first principles.
The landscape isn't static : it's rewritten continuously by the population's own motion. Basins deepen, split, and vanish as units move through them so that geometry and dynamics co-evolve.
This picks up a question from our earlier work, where we found Waddington-like branching emerging inside Hopfield classifiers but the model was too tangled to fully understand why. Sandscapes is us going back and building the minimal version to find out. journals.aps.org/prresearch/a...
The intuition spans biology and ML: ant castes, blood cell lineages, even artificial neural nets specializing on digits, all cases where a population of units differentiates while collectively reshaping its own decision landscape.
Congratulations to the brand new Dr Leah Friedman ! A fantastic defence (despite being the hottest day in Paris ever … so far). It has been a great pleasure to collaborate with Leah over the last 2 years or so.
28 ans après (et deux étoiles plus tard), les concours en pleine Coupe du Monde, une forme de retour aux sources. Je ne suis pas stressé (c’est ce que je me dis)
La famille a fait une vidéo, on reviendra quand le drapeau bleu blanc rouge géant sera sorti pour la Coupe du Monde . (D’autant plus surréaliste que l’Barouf est historiquement le bar des fans de l’OM !)
Very happy to participate in the QBio 'Cancer and Immunotherapy' Symposium in Paris on June 22nd ! Registration is still open docs.google.com/forms/d/e/1F...
Quels que soient le lieu, la période ou l'institution, c'est toujours la même histoire. Il y a quelque chose de fascinant dans cette incapacité à prédire ce qui arrive systématiquement !
Contraste Europe-Amérique assez saisissant ce matin pour les 2 événements sportifs actuels les plus populaires de part et d'autre de l'Atlantique.
We are hiring post-docs ! If you are interested in projects at the interface between physics, biology and machine learning (AI ?) please contact me ! More details here www.francoisresearch.org/positions
Editor in chief of Development @jamesbriscoe.bsky.social opening the floor today at the Allen Institute Lake Conference 2026 meeting ! @biologists.bsky.social
J’aime tellement les vitrines saisonnières ou thématiques du Valet de Coeur. Le Printemps s’en vient ! #rueStDenis
Leaving Tokyo today, glad I could enjoy a few early cherry blossoms ! 🌸
Happy to be back in Tokyo for the EPIC symposium ! sites.google.com/g.ecc.u-toky...
Printing out one of the Waddington Landscapes optimized in our recent paper !
On a side not, I am very proud of Grégoire who included a Rabelais' citation to talk about our work, he and I are still a bit French after all.
Just tested it, it is crazy (and it is directly translated in French for me !)
Mon téléphone est mort de froid mais j’ai réussi à prendre une photo ! Très froid mais très beau !