The 'molecular clock hypothesis' is critical for evolutionary theory. If it fails, many evolutionary speculations will fall as well. Yet, there is abundant evidence that mutations in the Y chromosome have happened at different rates among different people groups. If this is true, nobody an know how long ago 'Y Chromosome Adam' lived.

Notes:

My Review of Nathaniel Jeanson's Traced

Ding et al. 2021. Mutation Rate Variability across Human Y-Chromosome Haplogroups. Mol Biol Evol 38(3):1000-1005.