A survey of anatomical features that appear vestigial, redundant, or poorly routed, where evolution’s iterative trade-offs left structural oddities with debated or hidden functions.
Key Takeaways
Numerous anatomical structures dismissed as “useless” have later revealed protective or regulatory roles that were not initially apparent.
The retinal blind spot spans roughly 9 full moons in the visual field; brain interpolation fills the gap, though the exact neural mechanism remains contested.
Male nipples, the recurrent laryngeal nerve’s long detour, and external testicles are classic examples of evolutionary path-dependency rather than clean design.
Tonsils were routinely removed for decades as vestigial; current evidence suggests they may act as a barrier preventing pathogens from reaching deeper tissue.
Several listed quirks are better described as open research questions than settled anatomy, making this a map of gaps as much as a list of facts.
Hacker News Comment Review
Commenters repeatedly challenged the “useless” framing: the urethra routing through the prostate is a concrete counter-example, where prostate swelling during erection occludes the urethra and reduces bacterial bladder infection risk.
The tonsil case resonated as a cautionary pattern: medical consensus once labeled a structure vestigial, acted on that assumption surgically, and is now revising the call, suggesting humility is warranted across the whole list.
A secondary thread treated the article as a PhD topic generator rather than a list of known facts, noting that several “quirks” mark the boundary of what is actually understood, not what is understood to be bad design.
Notable Comments
@snthpy: Frames evolution as Agile: “responding to change over following a plan” – shorthand for why path-dependent anatomical debt persists.
@ivanb: Notes vas deferens and laryngeal nerve look like “easy pickings” for gene editing refactors, but flags the horror of opening that door as the real risk.
@odyssey7: “Part of this reads like a shortlist of things that doctors and scientists don’t know enough about yet” – reframes the article as a research gap map.
