Evolution and The Knightian Blindspot of Machine Learning
Authors: name: Joel Lehman; name: Elliot Meyerson; name: Tarek El-Gaaly; name: Kenneth O. Stanley; name: Tarin Ziyaee
Published: 2025-01-22 18:38:41

Abstract: This paper claims that machine learning (ML) largely overlooks an important
facet of general intelligence: robustness to a qualitatively unknown future in
an open world. Such robustness relates to Knightian uncertainty (KU) in
economics, i.e. uncertainty that cannot be quantified, which is excluded from
consideration in ML's key formalisms. This paper aims to identify this blind
spot, argue its importance, and catalyze research into addressing it, which we
believe is necessary to create truly robust open-world AI. To help illuminate
the blind spot, we contrast one area of ML, reinforcement learning (RL), with
the process of biological evolution. Despite staggering ongoing progress, RL
still struggles in open-world situations, often failing under unforeseen
situations. For example, the idea of zero-shot transferring a self-driving car
policy trained only in the US to the UK currently seems exceedingly ambitious.
In dramatic contrast, biological evolution routinely produces agents that
thrive within an open world, sometimes even to situations that are remarkably
out-of-distribution (e.g. invasive species; or humans, who do undertake such
zero-shot international driving). Interestingly, evolution achieves such
robustness without explicit theory, formalisms, or mathematical gradients. We
explore the assumptions underlying RL's typical formalisms, showing how they
limit RL's engagement with the unknown unknowns characteristic of an
ever-changing complex world. Further, we identify mechanisms through which
evolutionary processes foster robustness to novel and unpredictable challenges,
and discuss potential pathways to algorithmically embody them. The conclusion
is that the intriguing remaining fragility of ML may result from blind spots in
its formalisms, and that significant gains may result from direct confrontation
with the challenge of KU.