Sentry Bio · Research

Evolution as Active Geometry

We assumed the history of life was written in the language of chemistry.
It turns out, the universe wrote it in geometry.

Authors: Rohit Fenn & Amit Fenn
Status: Preprint 2025

The Parking Problem

Imagine you are trying to draw your family tree on a sheet of paper. You draw yourself. Above you, two parents. Above them, four grandparents. It seems simple. But the math of life is explosive. By the time you go back just 30 generations—roughly the time of the Norman Conquest—you have over one billion ancestors.

If you try to draw a tree with a billion dots on a flat sheet of paper, you run into a physical crisis. The dots on the edge get crushed together. There is simply no room left to add the next generation.

This is the central paradox of evolution. If space is flat, a branching species should suffocate itself in a few dozen generations. And yet, life has been branching for 3.5 billion years.

"If biology were flat, life would have suffocated itself a billion years ago."

Nature must have invented a way to create room where there was none. It did not change the math of multiplication; it changed the geometry of the world it inhabits.

Euclidean
κ = 0
High distortion
Spherical
κ > 0
Severe distortion
Hyperbolic
κ < 0
Minimal distortion
Tree depth 4
Figure 1. Tree embeddings in spaces of constant curvature. In flat space, history creates crowding. In hyperbolic space, history creates room. Drag to rotate.

The Ruffle

Life solves this problem the same way a kale leaf or a piece of coral solves it. If you want to fit more surface area into a tight boundary, you don't stay flat. You ruffle.

Mathematicians call this negative curvature—a geometry where there is more space than you expect. By curving, the universe creates extra elbow room at the edges of time.

We have known for years that evolution looks like a tree. But we didn't know the exact shape of the ruffle. It turns out the universe has picked a very specific shape—and it picked it for a very specific reason.

Geometric Response
Information Rate (h) 0.50 bits
Curvature (κ) 0.12
EUCLIDEAN · STABLE

Increase information density. At h ≈ 1.6—the entropy rate of DNA—the manifold buckles into a precise saddle shape.

Figure 2. The Ruffle. As information density increases, space must curve negatively to prevent data collision.

The Measured Constant

Think of evolution as a game of telephone played across time. DNA creates information at a limit—roughly 1.6 bits of useful new code per mutation event.

If the geometry is too flat, everyone is too close; the unique messages blend together. If the geometry is too curved, the branches spread apart so fast that the signal dissolves into noise.

There is exactly one curvature where the rate of expansion perfectly matches the rate of information.

κ = (h ln 2)²
The Geometric State Equation of Life

We trained a neural network on 5,550 genomes spanning all domains of life. We gave the AI no rules about trees. No taxonomy. We said only: "Arrange these organisms in a way that compresses the data best."

And when we measured the curvature of the resulting manifold?

κ = 1.247 ± 0.003

Five independent neural networks. Different initializations. They all converged on the same geometry. Coefficient of variation: 0.24%—precision comparable to measurements of fundamental physical constants.

Key Result

This is not parameter fitting. It is thermodynamic necessity. The curvature emerges independently from neural compression, phylogenetic tree optimization, and information-theoretic derivation. Three methods, three fields, one constant.

κ = (h ln 2)²
for tree topology n = 2
1
Phylogenetic Tree
Measure entropy from tree depth & diversity
h = 1.77 bits
2
Theory
Apply curvature-entropy law
κ = 1.51
3
Embedding
Measure optimal curvature
κ = 1.45
4
Validation
Compare prediction vs measurement
Error: 3.8%
Pearson r = 0.996 across 16 systems · Theory explains 99.3% of variance
Figure 3. The curvature-entropy validation loop. Theory predicts curvature from phylogenetic measurements, which is independently measured via neural embedding, then validated.

The Virus as Test Particle

If curvature reflects phylogenetic depth, then systems with different evolutionary timescales should organize at predictably different curvatures. Recent outbreaks should appear locally flat. Ancient lineages should be maximally curved.

System Divergence Predicted κ Measured κ Error
Zika virus~10 years1.141.205.4%
SARS-CoV-2~5 years1.341.321.5%
HIV-1~40 years1.511.453.8%
Cytomegalovirus~180M years1.811.6013.0%
All cellular life~3.5B years1.231.2471.4%

Correlation with phylogenetic depth: ρ = 0.84 (p < 0.001). Correlation with mutation rate: ρ = 0.12 (not significant). Substrate chemistry does not determine geometry—phylogenetic depth does.

Dynamics of Selection
Mutation Variance Optimal
ACTIVE NAVIGATION
Surviving lineages 0
Extinctions 0
Survival rate 0%

Each particle is a lineage. Color shows proximity to the boundary—safe center fades to danger at the edge.

Figure 4. The Evolutionary Light Cone. Organisms must "surf" the inner wall of the manifold. Touching the boundary means selection death.

Biology is Active Geometry

"We have effectively measured the speed of light for biology."

For centuries, we have searched for the Laws of Biology. We looked for them in the behavior of animals, or the chemistry of enzymes.

It seems we should have been looking at the shape of the space itself.

Evolution is not a series of accidents. It is the active navigation of a necessary geometry. The players change—dinosaurs rise, empires fall, viruses mutate—but the stage remains the same.

It is a stage built of hyperbolic curvature, defined by the fundamental limits of information, waiting to be explored.

κ = 1.247

Biology is active geometry.