Can long term use of cannabis change your eye colour? Why do adults feel the cold more than kids? And what will the next stage of human evolution look like?  Dr Karl answers these questions and more on triple j Mornings with Lucy Smith.

What role do genetics play in determining how smart someone will be? Why are rainbows always the same shape and colour? And where do the vitamins in fruit and vegetables come from? Dr Karl answers these questions and more on triple j Mornings with Lucy Smith.