In Season 4 of IFLScience’s podcast The Big Questions, we’ve delved into some of the most intriguing (and biggest) scientific puzzles of 2024, from whether or not octopuses are sentient to the reasons why we’re the only surviving human species. We’ve even taken on the supernatural.

Hosts Dr Alfredo Carpineti, Rachael Funnell, Katy Evans, Tom Hale, and Laura Simmons were joined by international guest experts to investigate questions and problems at the very limit of our knowledge. What did we learn? Find out below.

Episode 1 – Why Are We The Only Surviving Human Species?

Homo sapiens – us – are the only surviving human species. Professor Chris Stringer, human evolution research lead at the Natural History Museum joins us to discuss why – and what happened to those who came before us.

Episode 2 – How Is Climate Change Impacting Our Health?

We speak with author and neuroscientist Clayton Aldern to explore the science that backs up what we know about how extreme weather can alter the way we think, act, and feel.

Episode 3 – Is Evolutionary Biology Sexist?

Together with zoologist and presenter Lucy Cooke, we explore how biases in science have affected – and sometimes prevented – what we know about animal biology in some truly eye-opening ways, and hopefully debunk some myths along the way.

Episode 4 – Can We Make Dogs Live Longer?

Saying goodbye to a pet is an incredibly painful time in a person’s life, but what if there were a way we could help our pets live longer, better lives? We speak with Celine Halioua, who’s been exploring that very question as CEO and founder of Loyal.

Episode 5 – How Will The Solar System End?

While our Solar System is stable, it won’t be that way forever. With the help of astronomer Dr Jon Zink, we cast our mind’s eye far into the future and explore how it will end.

Episode 6 – How Did Dinosaurs Have Sex?

Grab your headphones and switch on incognito mode – palaeontologist and science writer Riley Black joins us to dive into what science knows about the sex lives of dinosaurs.

Episode 7 – Are The Drugs Of The Future Coming From The Deep Ocean?

We speak with Dr Sam Afoullouss, a marine scientist at the University of South Florida, about the interesting chemistry found in the deep sea and its potential to be the pharmacy of the future.  

Episode 8 – What Would A Human On Mars Look Like?

In this episode, we’re joined by Scott Solomon, author and professor of biosciences at Rice University, to discuss whether settling on an alien world with an environment unlike Earth’s could take us on a different evolutionary trajectory.

Episode 9 – Are Octopuses Sentient?

It’s no secret that octopuses are intelligent – but are they sentient? And how is that reflected in the way that they’re treated? We tackle these complex questions with Sy Montgomery, author of Secrets of the Octopus, and Sophika Kostyniuk, Managing Director at the Aquatic Life Institute.

Halloween Special – Britain’s Most Haunted Castle: IFLScience Takes On The Supernatural

In this special bumper Halloween episode, we ask can fear be fun, why do people believe in ghosts, and why does the paranormal have us in such a chokehold?

Bonus Episode – Why Do Humans Love Playing Competitive Games?

We sit down with neuroscientist and physicist Kelly Clancy to find out why we love competition so much, and what our long history of gameplaying together can teach us about each other – and ourselves.