I recently was noticing there was a lot of information in regards to Median-Joining Network divergence estimates for certain Haplogroups.
This median from what i can gather can predict when a haplotype entered an area, as an example, T ( old K2) entered cornwall and Wales for the first time in 236 CE, while G2 entered England in 443 BCE. With this we can summise that G2 arrived before the Romans, and T while the Romans where in Britain.

If I understand this can also be used with ancient languages entering an area


I think only 37 and 67 markers can be used to calculate these "creation" times



I was wondering if anyone has any knowledge on this topic