[Heartlander]

It only takes a single point mutation to "make a new function" that allows people to resist malaria.

Is this truly a mutation if the ability already existed?

[DWPittelli]

I said: It only takes a single point mutation to "make a new function" that allows people to resist malaria.

You said: Is this truly a mutation if the ability already existed?

A mutation is an error in the DNA copying. A single point mutation changes just one of the base pairs in the DNA (e.g., A becomes G in the ATGC code). Yes, the rise of sickle-cell anemia was due to a mutation. And yes, the linear clumping pattern of the red blood cells that occurs in carriers of this mutation is a new function that did not exist before the mutation.