What does it mean to say that mutation is the ultimate source of genetic variation?

When it is said that mutation is the ultimate source of genetic variation it means that it creates several new combinations which is similar to  meiosis and fertilization because  new alleles and genes appear. It is just about some common points.

Since a female is both xx chromosome and the male passes down the x chromosome, than the offspring would be female since a female is xx.

Ithink sanforcisco california (i am not 100% sure) if you feel the opposite so that lol