From the pressurized space suits to living in underground spaces, it's clear that living on Mars would cause irreversible biological changes to any humans living there, to the point that it may be impossible for them or their descendants to return to Earth. With bigger heads and lighter bodies, might we also end up looking like Martians?

PLUS:

• Yellowstone’s predators battle it out, and wolves remain top dog
• fossil of the earliest veggie-eater found in Nova Scotia
• Covid is disappearing in animals, which is good news for deer but not as good for humans
• how genes affect our lifespan more than we thought

An elephant’s trunk is incredibly strong and rugged, and yet it is one of the most sensitive touch organs in the animal kingdom. New research reveals that this sensitivity is partly powered by over 1000 whiskers.

PLUS:

• A new 'inside out' solar system is making astronomers question planet formation
• Paleo-Inuit people in the high Arctic were masterful seafarers, new study shows
• Two-month-old babies can categorize objects in their brain
• How insects deal with smog or microplastics can impact them and the environment

Researchers made the surprising discovery that Alaska beluga whales have swinging sex lives — and that could be their key to survival in the warming Arctic.

Plus:

• mission to the 'doomsday' Thwaites glacier in Antarctica ends in disappointment
• near-infrared light therapy offers hope to football players with brain injuries
• with nuclear power making a comeback, what's changed since the last Atomic Age?

Scientists spent nearly 25 years studying close to 800 polar bears in the Barents Sea region and discovered that those polar bears seem to be doing just fine, even though melting sea ice is also a major issue.

PLUS:

• Sargassum seaweed is becoming such a problem, you can see it from space
• Why some people only get mild sniffles with a cold and others get sick
• A woolly rhino's DNA found in an ancient wolf’s stomach reveals their quick demise
• How to change a memory — one scientist's quest to understand memory permanence

Some dogs are more adept at learning language than others. Researchers studying these special dogs discovered that, much like toddlers, these smart furry canine companions can pick up words just by eavesdropping on their owners' conversations.

PLUS

• Tracking space debris using seismometers
• Using nitrogen to boost trees
• How Mars shapes our climate
• Extracting ice age mammoth RNA and using lichens to find dino bones

We may share a common ancestor with chimpanzees, but somewhere along the evolutionary line to us, our brains took a major detour. New research suggests that chimpanzees can rationally weigh evidence, a trait that used to be thought as uniquely human.

PLUS:

• Why penguin-eating pumas live closer together in Patagonia
• Ants sacrifice the strength of individual workers for quantity
• Mapping the landmass beneath Antarctica's massive ice sheet
• How deep sea ocean environments affect fish body shape

An unassuming fossilized slab in the basement of a museum in Brazil turned out to be 110-million-year-old dinosaur vomit, and inside that vomit were the bones of two strange, seagull-sized pterosaurs.

PLUS:

• Loss of fresh groundwater is now the leading driver of sea level rise
• How doubting your self-doubt makes you doubt less
• A huge black hole in a peculiar galaxy may date from the universe’s earliest moments 
• Shining a light on where viruses hide out in our bodies, and how they make us sick

On this week’s episode of Quirks & Quarks, it's our ever-popular and always satisfying Holiday Listener Question Show that includes: 

Why did a Canadian astronaut's eyesight change when she went to space? 

How is the dust inside our homes changing? 

Why do some professional athletes stick out their tongues when they play?

Why are most fruits round, but bananas and pineapple are not? 

What would have happened if the dino-killing asteroid never struck Earth?

We'll satisfy all these scientific curiosities and many more!

In 2000, Quirks & Quarks celebrated its 25th anniversary by travelling forward in time — to 2025 — to find out how science had changed in the years since. In this fictitious future, our present, Zargon the robot, wakes up a Bob McDonald clone from the year 2000 to speak with scientists about 25 years of science. It's a mindbending audio time-capsule with predictions that were oddly prescient, sometimes unsettling or wildly wrong.

We talk to authors of some of this year’s most fascinating science books in our annual Holiday Book Show.

INCLUDING: 

• Questioning the purpose of whale song — for love or echolocation?
• Journeying through deep geological time to better tackle problems of the future
• Biological sex is complicated but that's what helps animals like humans thrive
• Mini reviews of: The Martians by David Baron, Dinner With King Tut by Sam Kean and The Mind Electric by Pria Anand.