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