Enthusiasts think direct democracy is spreading because the traditional type is ailing.

ECONOMIST: If you thought Germany did not do referendums, think again

"It's the most direct evidence of farming spreading by migration of peoples that you could hope to find, " said lead author Pontus Skoglund, an Uppsala University graduate student.

WSJ: Migrations Spurred Agriculture Spread, Studies Indicate

Health officials believe people are contracting the virus through direct contact with infected fowl and say there has been no evidence so far that the virus is spreading easily between people.

NPR: China Kills Market Birds As Flu Found In Pigeons