Chevy Chase Good Genes or Good Docs?

1221_chevy_chase_good_genes_launchClark Griswold aka Chevy Chase is having the holiday of a lifetime.

Here's the 46-year-old comedian around the time "National Lampoon's Christmas Vacation" came out in 1989 (left) -- and 23 years later, the 69-year-old former "Community" star at an event earlier this year (right).


More Good Genes or Good Docs: