Modern people belonging ancient basal haplogroups

[alvaroabascal]

I'd like to comprehend the ultimate meaning of modern people belonging ancient basal haplogroups (e.g. P1*).
I'm PH92*. Well, I get that unless more people with similar SNPs are investigated, this is a "provisional" haplogroup.
But what about people belonging to these old basal haplogroups, like P1*, which is like 20.000 years old. Of course these people have gone under approximately the same number of mutations as the rest of us with "modern" haplogroups, it's just that these mutations are not "classified".
Does it just mean that they might belong to a small group that hasn't been well investigated? Does it mean that the possible origin of that old haplogroup (P1 in this example) is the place where they live now? Or does it mean ... just nothing?

Thanks in advance.

[stibbs]

IMHO these groups ("paragroups") could be the result of undersampling or genetic bottlenecks. Even old subclades (say 2000+ ybp) may just be hanging on, with perhaps only 10 living members, sampled or not.

[Artmar]

Such haplogroups as P1 or K2b* aren't really basal or very rare but definitely undersampled and even if tested - mostly on a very basic level for a number of socioeconomic reasons.

Every modern person does not belong to the basal line because it bears as recent mutations as other people. Some lines are just less numerous or tested compared with other lines.