FamilytreeDna provides additional information on Finnish subgroups of the YDNA I1 haplogroup. FamilytreeDna certainly has the widest selection of YDNA samples, so you can trust the results with great certainty. What makes the results interesting is that FamilytreeDna reports the map locations of the samples based on the ancestral information of the sample owner. This information is mainly based on church records or population register data of ancestors. In the results, based on the TMRCA values mentioned in my previous update, you can see the places of residence of the ancestors of the young Z133 group. It is particularly interesting to note that, based on the ancestral data, the historical starting point of the group Z133 can be found, not only in South Ostrobothnia, but also in Karelia, which was handed over to Russia after WWII. It is natural to assume that a large part of the Eastern Finnish Z133 samples have come from the ceded Karelia during the last 500 years of the historical time period. Migration from the Karelia can extend even more to the past, but the Finnish census and church registers are not available from the time before the 16th century.
This example proves that interpreting the present requires knowledge of history. How Z133 ended up in Karelia, I don't dare to present my interpretation, although according to known prehistoric information I see a coherent explanation.
Each dot corresponds a group if samples, but FamilytreeDna doesn't tell the logic and how the maps are scaled.
Z133:
In addition, the Finnish L258:
And only CTS2208, whose downstream branch L258 is:
