|Confounded cytosine! Tinkering and the evolution of DNA. .|
Poole A, Penny D, Sjoberg BM
Nature Reviews Molecular Cell Biology (2001)
Category: evolution ¤ Added: Sep 10, 2002 ¤ Rating: ◊◊◊
Early in the history of DNA, thymine replaced uracil, thus solving a short-term problem for storing genetic information--mutation of cytosine to uracil through deamination. Any engineer would have replaced cytosine, but evolution is a tinkerer not an engineer. By keeping cytosine and replacing uracil the problem was never eliminated, returning once again with the advent of DNA methylation.