Therefore, natural geographic barriers are attributed to be the reason as to why the Bornean orangutans were eventually isolated and ended up colonizing other regions. In addition, this geographic isolation also indicates that the Bornean orangutans did not undergo a severe genetic bottleneck. With the Borneo orangutan, selection was found to have been found through physiological adaptations – most of which has to do with being able to adapt to the ever-changing climate on the Borneo island.
The geographic isolation of the Bornean orangutans, as a result of natural barriers, is believed to be the primary reason for their separation and subsequent colonization of other areas. This isolation also suggests that the Bornean orangutan population has not experienced a severe genetic bottleneck.  Adaptation through physiological changes was found to be the driving force behind selection in this species, with these adaptations being particularly important for coping with the changing climate on Borneo.