Don't bother with the site's wiki.

They have a reference to a mouse study on the front page of the site:

Weindruch R, et al. (1986). "The retardation of aging in mice by dietary restriction: longevity, cancer, immunity and lifetime energy intake." Journal of Nutrition, April, 116(4), pages 641-54.

For the evidence from the rat studies, perhaps start with this review article:

Overview of caloric restriction and ageing.

http://www.crsociety.org/archive/read.php?2,172427,172427