• Archaeologists make surprising discovery at Easter Island - turning everything we know on its head
• Monkeying around: Chimps adopt pointless social fads such as wearing grass in their ears, hilarious pictures show
• Earth and our entire Milky Way galaxy may sit inside a mysterious giant HOLE, scientists say
• Scientists rejoice as British trees evolve resistance to devastating ash dieback fungus
• What your favourite exercise tells you about your personality - and it's bad news for those who enjoy HIIT