Van Carman wrote:Steve Coffman in his book,Ezekiel's Medicine names the loss of the liver enzyme gulonolactone oxidase as the result of Adam's disobedience in the Garden Of Eden.Go to the Book of Genesis and read the account.Please have a happy new year,vitamin C users,Van
DanSco wrote:One theory is that the evolutionary advantage is the starvation advantage. A relatively large amount of glucose is used up to produce ascorbate. One can easily imagine the scenario where an ascorbate producer remains very healthy early on, but dies of starvation before the springtime comes. Also easy to imagine is the otherwise identical genetic mutant that uses no glucose for ascorbate, who is with scurvy but alive in the spring.
It is also said that domesticated animals produce less ascorbate than wild animals. People that raise animals would naturally like the animals that grew faster and larger and needed less food. If the reason that they grew faster and larger and needed less food was because they produced less ascorbate, then that trait would be inadvertantly selected for by breeding.
NaturopathMan wrote:It may also be simply that primates and guinea pigs get enormous amounnts of vitamin c in their diets so nature being as resourceful as it is may have figured that it is better to put energy towards things that are more of a necessity.
zucic wrote:I have done some search and found these interesting things:
(1) The compound called UDP-glucuronic acid is used by liver
to perfom detoxification.
(2) The same compound is an intermediate in ascorbate synthesis.
(3) UDP is still made by our livers.
(4) The first GULO gene mutation, which wreched the gene, occured a
long time ago, yet the remaining three enzymes are still working.
Here is a simple theory:
- There was a plenty of ascorbate in a diet of our ancestor, but some
environmental disaster forced these creatures to include some foods
which were ignored before. The same disaster maybe even caused
- Mutation spared small fraction of glucose, but large fraction of
UDP-glucuronic acid for detoxification.
- Significantly improved detoxification was an obvious advantage,
while the loss of ascorbate synthesis was not very significant, because
the newly introduced foods also contained ascorbate.
zucic wrote:I still think that loss of GULO lead to one more advantage: more efficient glucoronidation (a detox method) after
changing evolutionary niche.
I am always interested in the question as to why we lost the ability to produce vitamin C? Genetic studies have shown that humans, as well as other scurvy-prone mammals, was able to synthesize vitamin C endogously at one point, but lost this ability 25 million year ago.
Loss of GULO activity in the primate order occurred about 63 million years ago, at about the time it split into the suborders haplorrhini (which lost the enzyme activity) and the more primitive strepsirrhini (which retained it). The haplorrhini ("simple nosed") primates, which cannot make vitamin C enzymatically, include the tarsiers and the simians (apes, monkeys and humans). The suborder strepsirrhini (bent or wet-nosed prosimians), which are still able to make vitamin C enzymatically, include lorises, galagos, pottos, and, to some extent, lemurs.
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