At last report, the only animals not capable of synthesizing their own vitamin C were primates, monkeys, and guinea pigs. This is unfair if not actually discriminatory. It should be a prime objective of genetic engineering to introduce this ability into, eventually, humans. An experimental species suggests itself. This is just the big idea; I'll leave development of promoters and restrictors to staff.-- hagfish, Aug 05 2001 Monkfish Research Survey http://www.nefsc.nm...ead/popdy/monkfish/Mmm... Monkfish. [Uncle Nutsy, Aug 05 2001, last modified Oct 21 2004] Could you make it so I could synthesize my own pizza & coffee as well?-- Jim, Aug 05 2001 What exactly is a "hagfish"? Link! Peter! Link!-- Susen, Aug 05 2001 So, 'Hagfish', tell me, what exactly is the difference between a primate and a monkey?-- [ sctld ], Aug 05 2001 Primates are bishops. Ooops-- I meant apes. Thanks for the distinction.-- hagfish, Aug 06 2001 A hagfish is a relative of the lamprey. It generally feed on undersea carrion, does not swim to fresh water to spawn (as do lamprey), and as I understand it has the most copious slime of any fish. [hagfish-the-halfbaker, this description is not meant to reflect negatively on you, of course.]-- Dog Ed, Aug 06 2001 I appreciate the qualification. As noted in Peter's link, we have very tough skins. We have to. "Useless and repulsive".... indeed!-- hagfish, Aug 06 2001 ::::::applause::::::
and that concludes our zoology lesson for today <grin>-- Susen, Aug 06 2001 Yep, the hagfish said to be one of the more disgusting looking sea creatures around.
One of its rivals for the title, interestingly, is the monkfish. See link, but at least the monkfish tastes damn good once you get past the membrane.
(Speaking, of course, of the fish and not the Halfbaker)-- Uncle Nutsy, Aug 08 2001 So what's adaptively useful about the primates losing the ability synthesize (synthesise) vitamin C? Do primates use the formerly vitamin C synthesizing (synthesising) mechanism for something else?-- protean, Aug 08 2001 Possibly because synthesis (synthesis) was too metabolically expensive given the abundance of dietary vitamin C. Is there a demonstration that a mutual ancestor ever possessed the ability to form its own?-- hagfish, Aug 08 2001 As I understand it, primates lost the ability to synthesize vitamin C because we got enough of it in our diets. One day, the gene for one part of the process disappeared, and nobody noticed, so the non-vitamin-C-producing mutation didn't get selected against and happened to spread through the human population. It was only later, when humans started living on more restricted diets (no fresh fruits or meat) that the lack of the ability to synthesize vitamin C became a problem.
Apparently, humans still do perform most of the intermediate chemical steps necessary to make vitamin C, but then we throw everything away. Duh, oops. I bet that if gene therapy ever becomes easy & reliable, lots of people will patch their genomes to fix this little problem.
[Some googling turns up that we humans actually have two genetic defects affecting vitamin-C synthesis: one involving "lactonase" and one involving "L-gulonolactone". The lactonase defect makes us unable to synthesize C; the gulonolactone defect just makes the synthesis less efficient. Some people don't have the lactonase defect, and are therefore immune to scurvy. These are the people who survived the long European sea voyages in the middle of the millennium ... some other groups, such as desert nomads, have regained vitamin C synthesis ability.]-- wiml, Aug 14 2001 ...But I LIKE oranges.-- Madcat, Mar 25 2003 Ah, one of my pet likes (this kind of topic).
Basically, anyone who needs vitamin C is a mutant, much like anyone lactose tolerant is a mutant too!-- Freelancer, Mar 25 2003 // lots of people will patch their genomes // Aaaah, the future. Human genome patch 17647.33 is brought to you by the good people of Sunkist, reminding you that oranges are good, even if you don't need them anymore.-- Worldgineer, Mar 25 2003 random, halfbakery