According to the keyword positioning context, the alternative possibility refers to the extraordinary capacity of male primates to look out for the fates of infants did in some way pre-adapt members of this order for the sort of close, long-term relationships between males and females that, under some ecological circumstances, leads to monogamy。

 did in some way부터 해석이 안되네요. 주어 동사가 나와야하는데, 맨 마지막에 나오는 것 같은데, 그럼 females 다음에 that은 뭔가요?

did는 어떤 역할을 하는지 모르겠습니다.