4 ms·
If we're doing germline edits, the obvious thing to fix first is vitamin synthesis. There are a bunch of useful things other living things synthesise from first
by tialaramex 3y ago
If we're doing germline edits, the obvious thing to fix first is vitamin synthesis. There are a bunch of useful things other living things synthesise from first principles, and we don't so we need to eat something that has already synthesised the thing we wanted, and we can't cook or preserve it in any way that destroys the material we needed or it won't work. That's what scurvy is, a tree or a lizard just makes its own vitamin C, but humans don't, so, if you're stuck on a ship eating preserved food for months your body runs out of vitamin C and you get very sick and eventually die. But synthesising vitamin C isn't hard per se, it's just that the synthesis instructions can be deleted and the humans are descended from an ancestor who had such a deletion, we can put it back.
Once vitamin synthesis is back working, next up is amino acid synthesis. Amino acids are the constituent parts of proteins, your DNA is a bunch of instructions to fasten together a series of 22 different coded amino acids to make proteins. When you eat something, any proteins are broken back down into amino acids. Given some amino acids you can in principle make the others, but humans only make about half of them this way. As a result if your protein mix is wrong you are eating amino acids, and your body needs amino acids but some of them are different amino acids - and instead of synthesising the ones needed from spares you don't need using energy, which is abundant in most human societies, you just get sick and eventually (if you don't fix your diet) die. We should fix that.
- ruined 3y agoand then, crispr cat ears
- klyrs 3y agoNot the bombardier beetle's hydrogen peroxide cannon? I'll never understand furries.
- underlipton 3y agoI mean, do you want Zootopia, or do you want that weird (strangely enjoyable) Jamie Foxx Netflix movie? Because one might be mundane, but at least you don't have to worry about some guy blowing you across the block with his shrimp powers.
- Applejinx 3y ago(earflattens very slightly in Cat, otherwise impassive) Don't judge.
- m4rtink 3y agoLike that might be a bit problematic due to the existing ears but whatever - like, if designed well you might as well have an extra pair of fluffy cat/dog/fox ears and use it for improved echolocation. ;-)
- canadiantim 3y agoMakes you wonder why we naturally selected for ancestors who didn't have the vitamin synthesis machinery. Clearly there must have been some evolutionary disadvantage associated with vitamin synthesis, or else as you say it's clear benefits should have conferred an evolutionary advantage and still be with us today.
- tsimionescu 3y agoNot necessarily. If any early human diet that produced enough calories for them to live and procreate also happened to have plenty of vitamins, then synthesizing your own really didn't confer any evolutionary advantage. I'd also note I don't see any reason we'd want to synthesize our own vitamins now. It's virtually impossible to get a vitamin deficiency unless you try to eat a very restrictive diet for some other reason.
- smegger001 3y agoThere was little selection selecting against the loss it when it was abundant in out ancestors diet at that particular time and place. so by the time it became an issue it was already missing from the gene pool and as it is easier for a mutaion to break a gene than it is to gain function so its unlikely to mutate back into the genome by chance.
- tgbugs 3y agoVitamin synthesis is one of the most pointless things to add because it is something that is lost in many lineages over evolutionary time. The reason is that as long as there are environmental sources of a molecule the pressure to retain the ability to synthesize that molecule natively is zero or even negative, because the synthesis pathways for some of those molecules are quite nasty. You could do it, but those people would probably have increased cancer rates due to running nasty biochemistry in their own cells and eventually their descendants would lose the ability the synthesize it again because vitamin C is naturally present in their environment unless they are e.g. British sailors stuck on a boat for months with a evolutionary strange diet.
- deleted 3y ago[deleted]
- Ovah 3y agoI'm surprised how the conversation shifted from genetics to unethical germline editing of things that barely have clinical relevance. The rates of scurvy in the 21th century are low and definitely don't warrant super invasive editing germline cells (!), changes which become hereditary. Adding vitamin synethesis is super complex: it's not just a single SNP change but would require a whole new enzyme system. It's a very fine line from opening up a big old can of eugenics worms. Adding extra tRNAs is sometimes done in microbiology but any health benefits are extremely questionable. I've never before seen germline editing be a proposed 'solution' to malnutrition.
- lostemptations5 3y ago[dead]
- ordu 3y agoIf we are on this topic then we need to discuss a genetically modified gut microbiota. We do not need to edit genetically ourselves for some pityful vitamins. Microbiota could give us all we want. It could enable us to digest plastic, so we could eat food without removing its packaging. We could reduce severity of our waste problems by digesting plastic into relatively harmless poop.
- emiliobumachar 3y agoSounds unappetizing. Would you want to eat packaging if not for the - for now inevitable - digestion issues?
- ordu 3y agoYeah, you are right, it is not cool. How about to eat your fork? Can microbiota digest iron?
- teddyh 3y agoMaybe fix uricase production as well (eliminating gout).
- 1letterunixname 3y agoThe main issue is that evolutionary pressures have optimized for and against certain things that have fragile interplay of consequences with other genes. While it will become possible to restore auto-synthesis functionality, there are unknown risks associated with germ line edits reengineering Vit C or essential AA synthesis. It's currently illegal to do so in 70 countries. Specific, very positive beneficial edits that protect against infections, malnutrition, or pathological diseases should be allowed.