Comparing Silverback's edit at Jan 1, 20:30 to the one at Dec 31, 07:22 it seems to not have been a revert, http://en.wikipedia.org/w/index.php?title=Communism&diff=9017540&old... since he changed the disputed paragraph quite a bit.
He hasn't changed the paragraph as much as add to it. The problematic, undocumented original research is still there:
[Altruism]] [[evolution|evolves]] when those being helped have a strong likelyhood of sharing those same altruistic [[gene|genes]]. Altruistic, non-individualistic, [[memes]] such as communism may gain their persuasive, replicative power by riding on these genes, in much the same way that humans have been convinced to sacrifice for nationalism even though large nation states did not exist during most of their evolution. More selfish genes, which tend to reinforce or reward altruistic or cooperative behavior in others may also be of assistance to the communism meme.
Is the Libertas version that caused the original problem of which Silverback reinstated the following (that is all but the first sentence from above):
Altruistic, non-individualistic, [[memes]] such as communism may gain their persuasive, replicative power by "riding" on these genes, in much the same way that humans have been convinced to sacrifice for nationalism even though large nation states did not exist during most of their evolution. More selfish genes, which tend to reinforce or reward altruistic or cooperative behavior in others may also be of assistance to the communism meme.
And added:
The explanation for the development of [[Altruism|altruistic genes]] by [[evolution|natural selection]] is that those being helped have must a strong likelyhood of sharing those same altruistic [[gene|genes]].
to the beginning and:
Without the presence of altrustic behavior in humans and the appeal of altruistic behavior in others to humans, communism and other altruistic or collectivist memes, such as nationalism, religion, charity, etc. would have no appeal to humans
To the end. Given what he reinstated, unaltered, from Libertas' version I don't see how the edit in question can be described as anything but a reversion. A reversion with other changes made but a reversion nevertheless.
AndyL