# 🧠 A variational synthesis of evolutionary and developmental dynamics

**Karl Friston, Daniel A. Friedman, Axel Constant, V. Bleu Knight, Chris Fields, Thomas Parr, John O. Campbell** (2023) · *Entropy*

[![DOI](https://img.shields.io/badge/DOI-10.3390%2Fe25070964-blue)](https://doi.org/10.3390/e25070964)

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## Abstract

> This paper presents a variational formulation of natural selection, emphasizing the interplay between different 'kinds' of 'things' and their influence on each other. It formulates adaptive fitness as a path integral of phenotypic fitness, interpreting evolutionary and developmental dynamics through a Bayesian lens.

## Keywords

`variational synthesis` · `natural selection` · `Free Energy Principle` · `Bayesian mechanics` · `path integral` · `evo-devo` · `adaptive fitness` · `particular partition`

## Key Contributions

- Introduces a variational synthesis of evolutionary and developmental dynamics.
- Formulates adaptive fitness as a path integral of phenotypic fitness.
- Demonstrates the necessity of considering populations of distinct natural kinds rather than conspecifics.
- Establishes a framework for integrating slow phylogenetic processes with fast phenotypic processes.

## Methods

- Utilizes Bayesian mechanics to understand the relationship between phylogenetic and phenotypic processes.
- Applies the free energy principle to model evolutionary and developmental dynamics.
- Employs path integral formulation of stochastic dynamics and the renormalisation group.
- Describes natural selection and action selection as emergent properties of random dynamical processes.

## 🎯 Consulting & Tutoring

**Available for AI Research Consulting and Tutoring.** [Contact Daniel Ari Friedman, PhD](https://danielarifriedman.com/) for collaboration on Active Inference, Bayesian modeling, and computational biology.

## Citation

```bibtex
@article{2023_VariationalSynthesis,
  author = {Karl Friston, Daniel A. Friedman, Axel Constant, V. Bleu Knight, Chris Fields, Thomas Parr, John O. Campbell},
  title = {{A variational synthesis of evolutionary and developmental dynamics}},
  journal = {Entropy},
  year = {2023},
  doi = {10.3390/e25070964},
}
```

## File Inventory

- `AGENTS.md` (2,083 bytes)
- `2023_VariationalSynthesis.pdf` (1,488,327 bytes)
- `README.md` (1,815 bytes)
- `SKILL.md` (1,944 bytes)