Cheering greeted Brazil’s president-elect, Lula da Silva, when he appeared at COP27 this week. Madeleine Cuff brings us a report from the climate conference in Egypt, where Lula has made bold promises to protect the Amazon. She also tells us what we can expect from this year’s draft treaty - and why the text has been causing quite a stir.

There’s plenty going on in Space, with NASA’s Artemis mission now finally launching to the Moon. And the news that we may be able to look for wormholes (if they exist). These are different to black holes because they are traversable - handy if you happen to be an interstellar traveller looking for a fast route across the universe.

Our ancestors may have begun using sophisticated cooking methods as long as 780,000 years ago. The team explains how fish teeth have been discovered near hearths at an ancient settlement in Israel. And X-ray analysis suggests they may have been cooked in some sort of earthen oven.

Rowan visits a colony of leaf-cutter ants, who use an incredible method of farming fungi that evolved between 45 and 65 million years ago. David Labonte at Imperial College London explains how this complex and decentralised society operates.

And have you ever wondered why some poos float and others sink? Too much fat in your diet? Fibre maybe? Or is it gas? Well, new research has lifted the toilet lid on this age-old question, and the team shares the results.

On the pod are Rowan Hooper, Penny Sarchet, Madeleine Cuff, Leah Crane, Alice Klein and Sam Wong. To read about these subjects and much more, you can subscribe to New Scientist magazine at newscientist.com.

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