How much of the work is Hamilton Smith's http://en.wikipedia.org/wiki/Hamilton_O._Smith http://en.wikipedia.org/wiki/Hamilton_O._Smith compared to Mr. Venter's?

How much of the work is Hamilton Smith's http://en.wikipedia.org/wiki/Hamilton_O._Smith http://en.wikipedia.org/wiki/Hamilton_O._Smith compared to Mr. Venter's? I know he's not the type, but I'm really surprised that at least his name isn't mentioned more often.