Selective breeding does not occur in nature; it's only done by man. That is if you accept the given scientifc definition:

"Dictionary » S » Selective breeding Selective breeding

Definition
noun
The intentional breeding of organisms with desirable trait in an attempt to produce offspring with similar desirable characteristics or with improved traits.

Supplement
It involves breeding techniques such as inbreeding, linebreeding and outcrossing.



Selective breeding - definition from Biology-Online.org