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.