|Wesley R. Elsberry
Joined: May 2002
Evolution's Sweet Tooth
|Like icing on a cake, the surfaces of most animal cells are covered with sugars. These molecular sugar chains are capped off by a kind of sugar called sialic acid. While one particular sialic acid - called N-glycolylneuraminic acid (abbreviated as "Gc" in this article) - is found on most animal cells, it is not easily detectable on human cells. |
This is due to a genetic mutation that occurred many years ago, sometime after our last common ancestor with the great apes. All mammals except for humans tend to have about equal proportions of Gc and another sialic acid called N-acetylneuraminic acid ("Ac") in the body. Humans, meanwhile, only have trace amounts of Gc, but double the amount of Ac.
"You can't teach an old dogma new tricks." - Dorothy Parker