Dog breeders can selectively mate their animals so that eventually the descendants have shorter legs or longer hair than their forebears. However, the changes dog breeders can produce often result from losses in gene function.
कुत्र्यांची पैदास करणारे, मूळ जातीच्या कुत्र्यापेक्षा आखूड पाय असलेले वंशज उत्पन्‍न करण्यासाठी दोन वेगवेगळ्या जातीच्या कुत्र्यांची एकमेकात निपज करू शकतात.