Domestic dog (Canis familiaris), Smålandsstövare breed. Photo © Linathrash · Wikimedia Commons · CC BY-SA 3.0

Domestic dog (Canis familiaris), Bohemian shepherd breed. Photo © Krosandra · Wikimedia Commons · CC BY-SA 3.0

The ischial blaze is unique to the domestic dog in the entire family Canidae and remains in many breeds regardless of human selection for other traits.

The categorical absence of the ischial blaze in the wolf shows that the main ancestor of the domestic dog is an extinct species different from the wolf.

Robin and the Honey Badger, 22 March 2016

Photographs:
Ischial blaze of Canis familiaris
Ischial blaze of Canis familiaris