Some researchers believe that natural selection can favor traits benefiting groups to the disadvantage of individuals. Do not confuse group selection with kin selection. Probably the first hominid to live outside of Africa. A proposition explaining a phenomenon such as the function of a behavior or the origin of a trait. Hypotheses are derived from theory.
Natural selection favors traits improving the survival and reproduction of individuals.
The earliest primates were probably insectivores. They produce altricial offspring requiring a long time to maftire. R-selected species reproduce quickly and have many offspring. They produce many precocial offspring that quickly mature. A model of the evolution of cooperative behavior.