Your great-great-grandchildren might have webbed feet, gills and funny eyes, like cats, a scientist has warned.
But in another scenario, we might turn into tiny space dwarves with opposable toes for gripping things in low gravity.
Dr Matthew Skinner of the University of Kent worked out how humans might evolve in three different scenarios – including a ‘water world’ where the ice caps have melted.
To adapt to a ‘water world’, Dr Skinner predicted that humans would develop webbed hands and feet to help us swim. Regular foraging in shallow waters could also lead us to develop gills to help us breathe.
An additional layer in the retina – which cats have – would help us see in poor light under water. We might also evolve an extra translucent eyelid to protect our eyes when submerged.
If a meteor strike ushered in a new ice age, Dr Skinner said that our skin could become much paler to help us produce more vitamin D from less sunlight, we would have more body hair, and would develop more muscular physique.
Our noses and faces would become bigger to help warm inhaled cold air in the nasopharynx, the area behind the nose.
And if we were to colonise other worlds, the body could evolve to have longer arms and shorter legs, similar to orangutans, as walking is not as easy in low gravity.
We could develop opposable big toes as our feet become more useful for gripping things in low gravity. Humans may also reduce in size, thanks to a lack of predators in outer space.
Dr Skinner produced his predictions as the new series of science fiction drama Extant is launched on the Syfy Channel this week.