[neverdem]

What the article says is the they DO have identical DNA, but that changes can develop soon after fertilization. Another case of the headline being written by an brain-deficient moron.

No, check the link in comment# 1 and the keywords copynumbervariation, copynumbervariations and cnv. In the case of twins, copy-number variation means that the twins can have zero to multiple copies of the same gene.

[neverdem]

How epigenetics integrates nuclear functions

It's unrelated to the main theme underlying this thread, copy number variations, but since epigenetics was mentioned so often, I managed to come across this review article from a conference in 2005. It's fascinating, even if it may be already out of date.