You're a bit off on your dates for the Rev. Francis....he was in Taunton, Mass, and a pastor there, by 1639-40, 10 years before the date you give.
I doubt that there is only male ancestor of Francis Doughty, and, hard as it may be for us to believe, not everyone is interested in their family lineage, takes part in this hobby of ours or has placed their family on the web. The male members of my own family could care less, and there are lots others of the same ilk....so, the law of averages says his male descendants are out there...just uninterested. Too bad, too.