As cells get older, DNA gets damaged and lowers in DNA repair process what is the initial effect?
Since this is not my area of expertise, I searched Google under the key words "DNA aging" to get these possible sources:
http://www.chem-tox.com/DNA/aging.htm
http://www.benbest.com/lifeext/aging.html
http://www.clinsci.org/cs/107/0355/1070355.pdf
http://en.wikipedia.org/wiki/Senescence
http://www.sciencedaily.com/releases/2005/04/050411112330.htm
I hope this helpos. Thanks for asking.