2. Who Needs Vitamin C?
“Vitamin C is unique…as its essentiality as a nutrient is restricted to only a limited number of exceptional species among phylogenetically higher animals. In other words, nearly all higher animals can synthesize vitamin C…”
1991

3. Scurvy
R.I.P.
Vitamin C

4. A treatise of the scurvy, 1753
James Lind (1716 – 1799)
“…the most sudden and visible good effects were perceived from the use of the oranges and lemons; one of those who had taken them, being at the end of six days fit for duty.”
A treatise of the scurvy, 1753

5. Evolution is Testable Scurvy, Vitamin C, and Common Ancestry
1933: Vitamin C identified and described.
1934: Vitamin C artificially synthesized.
1913: Scurvy occurs in other primates.
1957: Scurvy due to lack of enzyme.
1907: Scurvy occurs in guinea pigs.
1907 Scurvy occurs in guinea pigs.
1913 Scurvy occurs in other primates.
1933 Vitamin C identified and described.
1934 Vitamin C artificially synthesized.
1957 Scurvy due to lack of enzyme.
Guinea Pigs
Chimpanzees
Orangutans
Monkeys
Tarsiers
Gibbons
Gorillas

6. Vitamin C Production
enzyme 1
enzyme 2
enzyme 3
enzyme 4
“GULO”
“VITAMIN C”
D-GLUCOSE
D-GLUCURONIC
ACID
D-GLUCURONIC
ACID LACTONE
L-GULONO-
LACTONE
2-KETO-GULONO-
GAMMA-LACTONE
L-ASCORBIC
ACID
Prediction: If the ancestors of humans, other higher primates, and guinea pigs originally had the ability to synthesize vitamin C, then each of these species should carry evidence of this lost ability in their genes.

7. 1 2 3 4 TACCCCGTGGAGGTACGCTTCACTCGCGGGGACGACATCCTGCTGAGCCCC
GULO-related sequence comparison from exon X
COW
GUINEA PIG
MACAQUE
ORANG
CHIMP
HUMAN
TACCCCGTGGAGGTACGCTTCACTCGCGGGGACGACATCCTGCTGAGCCCC
TACCCTGTGGGGGTGCGCTTCACCCGGGGGGACGACATCCTGCTGAGCCCC
TAACCGGTGGGGGTGCGCTTCACCCAAGG-GATGACATCATACTGAGCCCC
TACCCGGTGGGGGTGCGCTTCACCCAGAG-GATGACGTCCTACTGAGCCCC
TACCTGGTGGGGCTACGCTTCACCTGGAG-GATGACATCCTACTGAGCCCC
TACCTGGTGGGGGTACGCTTCACCTGGAG-GATGACATCCTACTGAGCCCC
GATGACATCATACTGAGCCCC
GATGACGTCCTACTGAGCCCC
GATGACATCCTACTGAGCCCC
premature STOP codons
TGA
GULO-related sequence comparison from exon III
COW
GUINEA PIG
CACTCGCCCTCAGACATCGCCTGCACTGACGGCTTCATGATCCACATGGGC
CACTCCCCCTCCGACATTGCCTGAACAGAGGGCATCATGATCCACAGGGGC
premature STOP codon
TGA
enzyme 1
enzyme 2
enzyme 3
enzyme 4
“GULO”
2-KETO-GULONO-
GAMMA-LACTONE
L-ASCORBIC
ACID
STOP
D-GLUCOSE
D-GLUCURONIC
ACID
D-GLUCURONIC
ACID LACTONE
L-GULONO-
LACTONE

8. Deactivation of GULO enzyme Human Chimpanzee Orangutan Macaque
Guinea Pig
Cow
Deactivation of
GULO enzyme