100,000 years ago there were about 5 species of humans. That homo sapiens survived is recently theorized that we were the most friendly.
Survival of the most friendly and cooperative is a new way of looking at evolution. Comparing dogs to wolves there is a mutation of chromosome 7 in dogs that make them more friendly. We have a similar shared trait of friendliness with dogs. Woof !

https://www.amazon.com/Survival-Friendliest-Understanding-Rediscovering-Humanity/dp/0399590668