https://www.google.co.uk/search?source=hp&q=human-canine+symbiosis&oq=human+canine+sym&gs_l=psy-ab.1.0.0i22i30k1l3.34760.38352.0.40353.19.17.0.0.0.0.92.940.17.17.0....0...1.1.64.psy-ab..2.15.853.0..0j46j0i131k1j0i46k1.XDNUX5TzY7M

https://neuroanthropology.net/2010/08/23/the-dog-human-connection-in-evolution/