Evolution of amino acids in dogs, curiosity question

Okey I have been assigned a animal. I got the dog it´s not the same kind as it is today. It´s more like a wolf. The dog is a scavenger and need to live near waterholes and down on the ground(not in the mountains where the air is thin). So this dog was like living betwen a rainforest and a steppe like where they cross in that kind of environment. But now 50 million years later I´m at my biology lab and I get a call from some archaeologist and they told me they have found the same specie of the dog in the mountain where there are very thin air and far between the waterholes. So I took a look at the bones and saw that there was some hemoglobin and vasopressin in their DNA. So somehow those 2 amino acids have envolved the dog and made it survive in the hostile environment. How is this possible? I have to look at this in a genetic way not an evolutionary way. As wide and long explanation as possible would be great. Thank you guys!