Frozen Fish Sticks

By: Racine Rangel

Jump on in – the subzero Arctic water is fine!

This is Sandra Tsing Loh with the Loh Down on Science and a chilling case.

What’s it like to live in the coldest location on the planet? Polar ice caps, bitter snow storms, and below freezing temperatures. Brrrr! But the Arctic is a dream destination for one fish — the Arctic Cod.

How do they survive such bone-chilling temps? Anti-freeze! That is, anti-freeze proteins in their blood! But where do these proteins come from?

Ask evolutionary biologist Christina Cheng from the University of Illinois, Urbana-Champaign. Her team has solved this fishy riddle. But it led to an unexpected twist.

The anti-freeze gene comes from a piece of D-N-A that was used for, well…nothing!

Random mutation of this seemingly unimportant genetic leftover allowed a brand-new gene to emerge. Non-freezing fish used this to their advantage in the glacial waters, and natural selection did the rest. No more frozen fish-sickles!

A true rags-to-riches story! Welcome to the Polar Bear Club, Arctic Cod!