If random changes in genes create new genetic variation in the gene pool, then what creates new genetic variation in the gene pool?

Answer choices:
- The bending of a ray of light
 - passenger pigeons
 - peachleaf willow
 - Warm air moving into cold air
 - random changes in genes
 - that material's properties
 - a tree falling
 - By wind and rain

 

     random changes in genes     