It would be quite a superpower to regrow entire body parts. CrowdScience listener Kelly started pondering this after a discussion with her friend on whether human tongues could regrow. Finding out that they couldn't, she asked us to investigate the extent of human regenerative abilities.

Presenter Alex Lathbridge travels to Vienna, a hotbed of research in this area. He meets an animal with much better powers of regeneration than humans - the axolotl. In Elly Tanaka’s lab he finds out how she studies their incredible abilities – and shows off his new axolotl tattoo.

Why can these sweet-looking salamanders regrow entire limbs while we can’t even regrow our tongues? Palaeontologist Nadia Fröbisch has looked into the evolutionary origins of regeneration, and it goes a lot further back than you might think.

And in fact, even humans are constantly regenerating, by renewing the building blocks of our bodies: cells. New cells grow and replace old ones all the time – although, in some parts of the body, we do keep hold of the same cells throughout our lives.

However, cell turnover isn’t the same as regrowing entire organs or limbs. But can we grow new body parts in the lab instead? We meet Sasha Mendjan, who creates heart organoids using our cells’ innate ability to self-organise. How far off are we from implanting organs, grown from a patient’s stem cells, back into the human body?

Contributors:

Presenter: Alex Lathbridge

Why do we have two eyes? Two ears? Two arms and two legs? Why is one side of the human body – externally at least – pretty much a mirror image of the other side?

CrowdScience listener Kevin from Trinidad and Tobago is intrigued. He wants to know why human beings – and indeed most animals - have a line of symmetry in their bodies. Yet, beyond their flowers and fruits, plants don’t seem to have any obvious symmetry. It seems that they can branch in any direction.

Anand Jagatia sets out to find out why the animal kingdom settled on bilateral symmetry as the ideal body plan. And it takes him into the deep oceans of 570 million years ago. Paleobiologist Dr. Frankie Dunn is his guide to a time when animal life was experimenting with all sorts of different body plans and symmetries.

Frankie shows Anand a fossil of the animals which changed everything. When creatures with bilateral symmetry emerged they began to re-engineer their environment, outcompeting everything else and dooming them to extinction.

Well... nearly everything else. One very successful group of animals which have an utterly different symmetry are the echinoderms. That includes animals with pentaradial - or five-fold - symmetry like starfish and sea urchins. And that body shape poses some intriguing questions... like “where’s a starfish’s head?” Dr. Imran Rahman introduces us to the extraordinary, weird world of echinoderms.

To answer the second part of Kevin’s question - why plants don’t seem to have symmetry – Anand turns to botanist Prof. Sophie Nadot. She tells him that there is symmetry in plants... you just have to know where to look! Beyond flowers and fruits, there’s also symmetry in a plants leaves and stem. The overall shape of a plant might start out symmetrical but environmental factors like wind, the direction of the sun and grazing by animals throws it off-kilter.

And, while the human body may be symmetrical on the outside, when you look inside, it’s a very different story. As listener Kevin says, “our internal organs are a bit all over the place!” Prof. Mike Levin studies the mechanisms which control biological asymmetry. He tells Anand why asymmetry is so important... and also why it’s so difficult to achieve consistently.

Contributors:

Presenter: Anand Jagatia

(Image: Orange oakleaf butterfly (Kallima inachus) on tropical flower, Credit: Darrell Gulin/The Image Bank via Getty Images)

It's a simple metal box that moves nearly all of our goods around the world. Designed for uniformity and interchangeability, the shipping container has reshaped global trade and our lives in the nearly 70 years since its creation.

But listener Paul wants to know if these heavy steel containers could be made with lighter materials to cut down on the fuel needed to transport them, especially when they're empty. Could we make shipping containers a more efficient process and reduce the shipping industry’s sizable greenhouse gas emissions?

Host Anand Jagatia travels to Europe's largest port in Rotterdam looking for answers. Speaking to environmental scientists and industry insiders along the way, he takes a look at how the humble container might be modified to once again remake global shipping, from materials, to designs, to how it’s shipped. And thinking outside the box, we explore which innovations might benefit the whole system – from machine learning to new, carbon-free energy sources.

For an industry that’s not always quick to change, we speak with the changemakers trying to disrupt the way 90% of the stuff we buy moves, in hope of a greener future.

Featuring:

Presenter: Anand Jagatia

(Photo: Port of Rotterdam, Maasvlakte Deep Sea Carrier Area. Credit: Sam Baker, BBC)

When listener Watum heard about the Titan submersible implosion in the news in 2023, a question popped up in his mind: if a machine that we specifically built for this purpose cannot sustain the water pressure of the deep ocean, how do fish survive down there?

In this episode, we travel with marine biologist Alan Jamieson to the second deepest place in our oceans: the Tonga trench. Meanwhile, presenter Caroline Steel speaks to Edie Widder about the creatures that illuminate our oceans, and travels to Copenhagen to take a closer look one of the strangest deep sea creatures and its deep sea adaptations.

But even fish have their limits! Scientist Paul Yancey correctly predicted the deepest point that fish can live, and it all comes down to one particular molecule.

So is there anything living beyond these depths? Well, there is only one way to find out…

Contributors:

Presenter: Caroline Steel

(Image: Deep-sea fish - stock photo, Credit: superjoseph via Getty Images)

CrowdScience listener Azeddine from Algeria has had bad handwriting since he was a child. In fact, it was so untidy that, when he later became a chemistry lecturer, his university students complained that they could not read his lecture notes. That was when he decided he had to do something about it.

In many languages across the world, all nouns are classed as either male or female, or sometimes neuter. The English language, however, only signals gender in its pronouns - he, she, it or they. For inanimate objects, gender just crops up in occasional examples like ships or countries, which, for some reason, are deemed female.

Contributors:

Presenter: Anand Jagatia

Buildings inspire many emotions, like awe, serenity or even dread. CrowdScience listener Siobhan was struck by this as she passed a huge apartment block with tiny windows; it reminded her of a prison. So, she asked us to investigate the feelings that buildings can trigger.

Contributors:

(Image: Rear view of woman surrounded by old traditional residential buildings and lost in city, Hong Kong, China. Credit: d3sign via Getty Images)

How do you think about the internet? What does the word conjure up? Maybe a cloud? Or the flashing router in the corner of your front room? Or this magic power that connects over 5 billion people on all the continents of this planet? We might not think of it at all, beyond whether we can connect our phones to it.

Another chance to hear one of our favourite episodes, inspired by a question from CrowdScience listener Simon: how much does the internet weigh?

First of all, this means deciding what counts as the internet. If it is purely the electrons that form those TikTok videos and cat memes, then you might be surprised to hear that you could easily lift the internet with your little finger. But presenters Caroline Steel and Marnie Chesterton argue that there might be more, which sends them on a journey.

They meet Andrew Blum, the author of the book Tubes – Behind the Scenes at the Internet, about his journey to trace the physical internet. And enlist vital help from cable-loving analyst Lane Burdette at TeleGeography, who maps the internet.

To find those cables under the oceans, they travel to Porthcurno, once an uninhabited valley in rural Cornwall, now home to the Museum of Global Communications thanks to its status as a hub in the modern map of worldwide communications. With the museum’s Susan Heritage-Tilley, they compare original telegraph cables and modern fibre optics.

The team also head to a remote Canadian post office, so correspondent Meral Jamal can intercept folk picking up their satellite internet receivers, and ask to weigh them. A seemingly innocuous question becomes the quest for everything that connects us... and its weight!

Producer: Marnie Chesterton

(Image: Blue scales with computer coding terms. Credit: Alengo via Getty Images)

Snakes are often seen as slithery, slimy and scary. But these intriguing non-legged creatures have made CrowdScience listener Okello from Uganda wonder how they move – more specifically, he wants to know how they climb trees so easily, and so fast.

Presenter Caroline Steel meets snake expert Mark O’Shea to investigate the ingenious methods different snakes use to scale a tree trunk, and gets a demonstration from a very agreeable corn snake at a zoo.

Snake movement isn’t just your typical S-shaped slithering: these reptiles move in a remarkably diverse range of ways. Melissa Miller from the University of Florida explains all the range of motion snakes can employ to effectively travel along the ground as well as at height.

Caroline witnesses this in action as we pay a steamy visit to the Everglades National Park in Florida, USA, tracking pythons across the vast swamps there. We find out why understanding these pythons’ movement is vitally important for conserving the local ecosystem.

Contributors:

Presenter: Caroline Steel

The CrowdScience team like a challenge. And listeners Jenny and Kai in the UK have come to us with a big one. They want to know how many flies have ever existed.

Flies first appeared around 270 million years ago, so presenter Caroline Steel prepares herself to calculate a very, very large number indeed. She enlists the help of Dr Erica McAlister, Curator of Flies at the Natural History Museum in London. As Erica introduces her to specimens from the Museum’s collection of over 30 million insects, they start with the basics. Like... how do you define a fly in the first place?

Caroline also explores the incredible diversity of flies… from fast-moving predators like robber flies which catch other insects on the wing to midges which are a vital part of chocolate-production; and from blood-sucking mosquitoes which transmit fatal diseases to the housefly buzzing lazily around a room.

And that leads to another fly-related question. Listener Brendan in Colombia wonders why they always fly in circles around a particular area of his apartment. For an explanation we turn to Prof. Jochen Zeil from the Australian National University who reveals that this apparently aimless behaviour is, in fact, a battle for sex.

And Collin in Barbados has e-mailed to ask how flies and mosquitoes benefit us. He’s had first-hand experience of their negative effects through contracting the disease chikungunya from a mosquito bite so he’s wondering if these insects are anything other than a nuisance. However, passionate fly advocate Erica McAlister is ready with plenty of reasons that we should be extremely grateful for them!

Contributors:

Presenter: Caroline Steel

(Image: Close-up of insect on leaf, Kageshwori Manohara, Bagmati Province, Nepal. Credit: Aashish Shrestha via Getty Images)