The Fermi Paradox, Percolation, and Inbreeding

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The Fermi Paradox, Percolation, and Inbreeding

What do cheetahs and genetic bottlenecks have to do with interstellar colonization? Glad you asked…

By James Davis Nicoll

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Published on July 17, 2026

Credit: NASA/JPL-CaltechComment 9

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Credit: NASA/JPL-Caltech

Well-timed synchronicity is a wonderful thing. There’s nothing quite like the intellectual zing one experiences when one scientific presentation casts an unexpected light on a seemingly unrelated theory or idea. I was the beneficiary of this phenomenon last week, when scarcely twenty-eight years 1 after reading Geoffrey Landis’ “ The Fermi Paradox: An Approach Based on Percolation Theory,” a Lindsay Nikole video essay on an entirely unrelated matter suggested an interesting embellishment.

But first! A quick background on the Fermi Paradox and on Percolation Theory as applied to it, for those of you who can’t be bothered to click the relevant links above.

The Fermi Paradox isn’t really a paradox so much as a question for which we currently lack a compelling, satisfactory answer. Back of the envelope calculations suggest that even modest propulsion technology should be sufficient for a single technological species to spread throughout the galaxy in a geological instant. However, when we look around, there is no evidence that this has ever happened 2. Thus, Enrico Fermi’s “But where is everybody?”

Landis’ proposed explanation centred on the fact that even for technologically sophisticated species, interstellar colonization is likely to be difficult and expensive. Not every civilization will bother to invest scarce resources in projects that by the nature of light-speed lag and distance can do them no direct good. Furthermore, light-speed lag and distance mean that child civilizations must be functionally independent of parent cultures. That could be a full stop to further expansions, as there’s no guarantee that colony worlds will want to invest in spawning their own co…