Re:Not actually genes are changed (Score 1)

There is some evidence of epigenetic changes being passed on to offspring in other systems.
This article from nature talks about some work from Emma Whitlaws group that sees heritable variation in coat colour of mice that are genetically identical. http://www.nature.com/ng/journal/v23/n3/full/ng119 9_314.html Subscription required
http://www.mmb.usyd.edu.au/research.php?person=whi telae Lab Webpage

Heritable epigenetic variation is however not Lamarkian, it is Darwinian inheriance. You still need to have variation that is selected, even if it is epigenetic.

For example you still cannot make a striped giraffe by stretching a zebra's neck as no cells from the zebra's neck will end up in the next generation. The cells that make sperm and eggs were all determined before you got your hands around the zebra's neck.

This result (the twins not the zebra) is not at all surprising to people in the genetics field and helps formalize well established concepts of incomplete penetrance of genetic traits and somatic (non reproductive tissue) mutation

The twin study did not look at reproductive tissues, but if the variation in epigenetics holds true there children of younger parents should be more like their parents