Final answer:
Y-chromosome Adam lived about 140,000 years ago in Africa, based on molecular evidence from Y chromosome studies, paralleling the timeline suggested by mitochondrial DNA for a common maternal ancestor.
Step-by-step explanation:
Y-chromosome Adam is a term used to describe the most recent common paternal ancestor from whom all living men are descended patrilineally. Molecular evidence obtained by examining the Y chromosome suggests that Y-chromosome Adam lived approximately 140,000 years ago in Africa. This evidence is in line with studies of mitochondrial DNA (mtDNA), which indicate that the matrilineal most recent common ancestor of all living humans lived around 160,000 years ago, also in Africa. This evolutionary timeline helps in understanding human evolution and migration patterns throughout history.