[jrhawley]

This whole topic of trans-generational inheritance and non-genetic factors affecting evolutionary fitness is, in my opinion, an undervalued topic in evolutionary biology today. If treating diseased cells with a particular drug elicits the over-expression of a microRNA to protect the cell, could that sustained expression be passed onto daughter cells without genetic mutation? That would be a case of some information (microRNA expression) being passed over generations of cells that influences phenotype (response to drug treatment). It's not strictly DNA-based, but it should still have some effect on evolutionary dynamics.

I (unsuccessfully) tried to tackle some of these ideas during my PhD, looking at other modifications to the DNA fibers like DNA methylation, transcription factor binding, and the 3D coiling of DNA inside the cell, and how that influences cell populations.

There are some interesting studies in plants from a few years ago [0-1] and more recent studies using some single-cell high throughput sequencing techniques [2] to investigate what role these non-genetic perturbations might play in evolution and disease.

[0]: https://journals.plos.org/plosgenetics/article?id=10.1371/jo...

[1]: https://academic.oup.com/genetics/article/188/1/215/6063285

[2]: https://www.nature.com/articles/s41586-019-1198-z