** Core Argument**
The barrier to preying on "mirror-image" life is likely lower than presumed due to:
Immediate energy from achiral fats.
Existing L-sugar pathways.
Existing D-amino acid racemases.
** 1. Fats: Achiral Energy Bridge**
Lipids (triglycerides), largely achiral, offer immediate energy. In E. coli for example, they constitute ~10% of dry mass, yielding ~27% of its macronutrient calories[1]). This non-chiral caloric gain from mirror prey could sustain predators during adaptation to chiral components.
** 2. Carbohydrates: L-Glucose Metabolism Evolved**
L-glucose metabolism has evolved at least twice despite its rarity in nature:
Pseudomonas caryophylli enzyme oxidizes L-glucose (Sasajima & Sinskey, 1979[2]).
Paracoccus sp. 43P has a full L-glucose catabolic pathway (Shimizu et al., 2012[3]).
This capacity for mirror-sugar adaptation, emerging even under low selective pressure, suggests the evolutionary barrier to such adaptations might be lower than anticipated.
** [...]**
Outline:
(00:10) Core Argument
(00:30) 1. Fats: Achiral Energy Bridge
(00:56) 2. Carbohydrates: L-Glucose Metabolism Evolved
(01:35) 3. Proteins: Racemases Handle D-Amino Acids
(02:09) Conclusion: Lowered Mirror Predation Barrier
The original text contained 4 footnotes which were omitted from this narration.
First published:
May 22nd, 2025
Source:
https://www.lesswrong.com/posts/zA6HWeoMeJWcrsfgK/mirror-organisms-are-not-immune-to-predation)
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Narrated by TYPE III AUDIO).
