Jon Voight -- Good Genes Or Good Docs?

Jon Voight's good looks can take the 'Heat.'

Here’s the 30-year-old 'Midnight Cowboy' star posing in a promotional shot back in 1969 (left) and 47 years later ... the 77-year-old father of Angelina Jolie -- at the Emmys last weekend (right).

'Mission: Impossible.'

The question is ...