HumansIt only takes a few gene tweaks to make a human voice Our capacity for complex speech might come from tiny tweaks to existing monkey genes that gave us flatter faces and more refined larynxes 51¶¯Âþ
LifeGrown-up chimps are less likely to help distressed friends Chimpanzees of all ages will comfort upset companions, but adult chimps do it less – perhaps because they are more selective about who they help 51¶¯Âþ