Ancient Peruvian civilisation grew mighty by harvesting guano
The Chincha Kingdom was transporting seabird excrement from islands to valleys as early as the 13th century, and this powerful fertiliser may have been key to its economic success
Why I’m still an environmental optimist – despite it all
It's hard not to despair about the state of the world today, but here are five reasons to be a little bit hopeful, says Fred Pearce
What to read this week: Bonded by Evolution by Paul Eastwick
We are told we need cynical strategies to "play" the dating game, but the science says this is totally wrong. David Robson enjoys an evidence-based takedown from psychologist Paul Eastwick
‘Roughly 109.5 golden retrievers’: a new way to measure ice
Feedback is always on the lookout for better ways to measure things, and was delighted to learn how the weight of ice is quantified in Austin, Texas
New Scientist recommends Hamnet, and its look at our links with nature
The books, TV, games and more that New Scientist staff have enjoyed this week
Exploring sci-fi treats from George Saunders and Matthew Kressel
In George Saunders's Vigil, a ghost visits Earth to help a dying oil tycoon, while terraforming efforts on Mars are about to bear fruit in The Rainseekers by Matthew Kressel. Emily H. Wilson's sci-fi column explores two very different short novels
Why adding cross training into your exercise routine is the way to go
There are huge benefits to ringing the changes when it comes to exercise, finds committed runner Grace Wade when she analyses the science
Rethinking our approach to BMI highlights the need for speed
We must find a balance between haste and getting mired in medical inertia
Putting a price tag on nature failed. Can radical tactics save it?
Biologists have long thought that speaking to nature’s economic value would persuade boardrooms it was worth saving. It hasn’t worked – so what, if anything, will?
The surprising origins of Britain’s Bronze Age immigrants revealed
About 4600 years ago, the population of Britain was replaced by a people who brought Bell Beaker pottery with them. Now, ancient DNA has uncovered the murky story of where these people came from