Question: How do genes mutate?

Xueyuan Jiang answered on 4 Mar 2017:

The genes mutate in many different ways. You can think of genes as beads on a string. Each bead has its own color and the string is of certain length. Sometimes when genes mutate, the color of bead would change (e.g. the red one would change to black). Sometimes, the length of the string would change. For example, more beads might be included in the string, and make the string longer.

In most cases, we don’t want any change to the bead or string, so gene mutation is a bad thing. But it can be good sometimes : )