Author: BBC World Service

Was there ever a time when life on earth was peaceful? Free of violence? No predators, no prey, just... vibes? Or has nature always been 'Red in Tooth and Claw'?

Have we always been eating each other?

Our listener Scott sent us on a quest to discover the origins of predators and prey, and to find out what all this ‘eat or be eaten’ stuff is really about.

Taking us back to the very dawn of life on earth, Professor Susannah Porter from the University of Santa Barbara lets Alex peer into an extraordinary world of microscopic warfare. It’s a dog-eat-dog (or, microbe-dissolve-microbe) world, with single celled organisms doing battle with each other. For billions of years, this was life on earth! Tiny, violent, and completely fascinating.

But what about bigger creatures? More complex ones - animals? Speeding forward several billion years, Alex arrives in the Ediacaran Period – a time of unusual tranquility, where strange, plant-like animals lived in relative peace. At the Natural History Museum in Oxford, UK, palaeontologist Dr Frankie Dunn shows him around.

So where did real predators come from, then? Alex is joined by Dr Imran Rahman as he ushers in one of the most extraordinary periods in Earth’s history – the magnificently named Cambrian Explosion! Here we find real predators, with teeth, claws, and impressive hunting appendages. Through the fossil record, we can see an arms race developing – as predators get more sophisticated, so does their prey. It’s ON.

Finally, Alex wonders if our own evolution, shaped as it has been by this predator-prey arms race, might have been very different without the threat of being chomped. Professor Lynne Isbell from the University of California, Davis takes Alex on a trip into our primate past, and tackles one of our most fearsome predators: snakes.

Presenter: Alex Lathbridge Producer: Emily Knight Series Producer: Ben Motley

World War II bombs were defused in Cologne, Germany, which has inspired us to explore the science of diffusion and defusing!

First, we hear how new, artificially intelligent video generators are modelled on diffusion. We also hear about the health impacts of home aroma diffusers and candles.

We’re joined by conflict-mediator Gabrielle Rifkind of the Oxford Process, to discuss the psychological stakes behind defusing conflict in wars and at home.

We also taste-test the difference between raw and cooked broccoli, learn about in-insect synthesis, and explore an anechoic chamber.

All that, plus many more Unexpected Elements. Presenter: Caroline Steel, with Tristan Ahtone and Edd Gent Producer: Imaan Moin, with Alice Lipscombe-Southwell, Minnie Harrop and Debbie Kilbride

ESA’s Solar Orbiter camera probe begins raising its orbit towards the sun’s poles, whilst Betelgeuse’s elusive buddy continues to sneak past our best telescopes.

Earlier this year, Solar Orbiter started to stretch its orbit over greater latitudes – effectively standing on cosmic tiptoes to catch a glimpse of the Sun’s poles. This week, we have seen the first ever pictures of them, and as solar scientist Steph Yardley tells us, the views will only get better.

Meanwhile, Andrea Dupree of the Harvard Smithsonian Center for Astrophysics and colleagues have had time to study new Hubble and Chandra telescope observations of the iconic star Betelgeuse searching for signs of its hypothesised binary companion – dubbed “Betelbuddy”. The papers that appeared on the Arxiv pre-print server have not yet been fully peer-reviewed, but it seems astronomers will have to keep looking.

Humans use machines to read gene sequences as best they can, but it takes time and is not perfect because we do not know what all of it means. Of course nature has its own genome reader – the ribosome. It is this that interprets the genetic instructions contained in our DNA and translates them into actual proteins. Viruses, of course, use it too when a cell gets infected. Shira Weingarten-Gabbay has this week demonstrated how scientists can make use of ribosomes too. Working somewhat in reverse, her team have identified many thousands of proteins previously unknown, that could for example provide targets for future vaccines or antivirals should the need arise.

Finally, Nanshu Lu and team in the University of Texas at Austin have been working for some years on two-dimensional wearable electronic “E-Tattoos” to monitor health non-invasively through our skin. Their latest work, describes “A wireless forehead e-tattoo for mental workload estimation”.

Presenter: Roland Pease Producer: Alex Mansfield Production co-ordinator: Jasmine Cerys George

Photo Credit: ESA & NASA/Solar Orbiter/SPICE Team, M. Janvier (ESA) & J. Plowman (SwRI)