Scientific American, November 2011

In this issue:

"The First Americans": Humans colonized the New World earlier than previously thought – a revelation that is forcing scientists to rethink long-standing ideas.

"Digging Mars": The Mars Phoenix mission has revived hopes that the Red Planet may be habitable.

"Can We Feed the World and Sustain the Planet?": A five-step global plan could double food production while greatly reducing environmental damage.

"The Wipeout Gene": A new breed of genetically modified mosquitoes carries a gene that cripples its own offspring.