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| ▲ | jlokier 3 days ago | parent | next [-] | | > All sugars have chirality so they would need some enzymes to eat their own mirrored sugars and another set of enzymes to eat normal sugars. Until mirrored life evolves enzymes to eat non-mirrored sugars, mirrored life will be at a large disadvantage. But with exposure to our environment, replete with non-mirrored sugars, that sets up a large evolutionary pressure in the direction of finding those enzymes, in addition to the mirrored enzymes they will already have for eating mirrored sugars. With such evolutionary pressure, it seems plausible mirrored life will evolve those enzymes, even though non-mirrored life appears not to have done so, or at least not retained it. Because there has been no equivalent evolutionary pressure for non-mirrored life to eat mirrored sugars. If mirrored life does evolve those enzymes, due to that asymmetric evolutionary pressure, then instead of being at a disadvantage, it might give them a temporary advantage over non-mirrored life. | | |
| ▲ | gus_massa 2 days ago | parent [-] | | It's not so easy to evolve new enzymes, but one of the main hypothesis is that at the beginning of the Carboniferous https://en.wikipedia.org/wiki/Carboniferous the plants invented lignin (that is the browns part of wood, that is mixed with cellulose that is the white part) and nobody knew how to eat eat, so for 50 millions years the dead trees accumulated on the floor and later transformed to the current mineral coal. Also cellulose and starch are very similar, they are chains of glucose, but bounded slightly different. We can split only starch, but we don't have enzymes to split cellulose, were "we" includes cows and a lot of animals that would really love to digest cellulose. I think some bacteria can digest weird sugars, even the mirrored versions, but they are more efficient digesting usual sugars. |
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| ▲ | jlokier 3 days ago | parent | prev [-] | | > All sugars have chirality so they would need some enzymes to eat their own mirrored sugars and another set of enzymes to eat normal sugars. Until mirrored life evolves enzymes to eat non-mirrored sugars, mirrored life will be at a large disadvantage. But with exposure to our environment, replete with non-mirrored sugars, that sets up strong evolutionary pressure in the direction of finding those enzymes, in addition to the mirrored enzymes they will already have for eating mirrored sugars. With such evolutionary pressure, it seems plausible mirrored life will evolve those enzymes, even though non-mirrored life appears not to have done so, or at least not retained it. Because there is no equivalent evolutionary pressure for non-mirrored life to eat mirrored sugars. If mirrored life does evolve those enzymes, due to that asymmetric evolutionary pressure, then instead of being at a disadvantage, the ability to eat both types of sugars might give them a temporary advantage. |
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