In the table below are links to Y-SNP calls for DNA samples from Mesolithic Scandinavia.
| Sample | Location | Date BC | Haplogroup |
|---|---|---|---|
| Hummervikholmen 2 | Southern Norway | 7502–7325 | I2c1-S6635* |
| Stora Förvar 11 | Stora Karlsö, Sweden | 7073–6810 | I1~M253 |
| Stora Bjers 1 | Gotland, Sweden | 7013–6629 | I2a1a2a~L1286* |
| Steigen 1 | Northern Norway | 4000–3814 | I2a1b-M423 |
Genetiker 
To samples from Hummervikholmen in Norway, dated 9452-9275 cal BP, came up with mito U5a1 (Hum1) and y-dna I2 (Hum2). Gunter et al, 2017.
Can you check Motala2 sample if also belongs to I2c1 s6635?
Motala 2 is I2c, but it’s negative for 3 out of 3 I2c1 SNPs (S6661, FGC18591, and S23479).
What about Boleraz and Barcin I2c samples?
Gunter et al claims the 9.000+ yrs old Hum 2 to be U5a1d and I2-M438, while their contemporary relatives buried at Stora Bjärs shows U4a1 and I2-M68.
Then the 5.700+ yrs old Steigen comes up with U5a1d and I2a1b-M423.
Any idea what caused the difference in y-dna, while the mt-dna-groups remained (seemingly) unchanged? Does that reflect an ‘evolutionary’ mutation of the y-dna, while the mt-dna remained more stable?!
http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2003703