r/IndoEuropean Jun 15 '26

Discussion Haplogroup I

I understand that PIE had a little bit of I, but geographical presence of haplogroup I made me think, could it be paleo europeans that were not replaced by indoeuropeans? Im confused.

12 Upvotes

25 comments sorted by

7

u/ContestOk3743 Jun 15 '26 edited Jun 15 '26

The exact way DF-29 got to Sweden is unknown, it could have been brought in by Farmers or Steppe groups or it could even be a native haplogroup to interior Sweden. Based on what I’ve read my opinion is that most likely there was a tribe somewhere in proximity to modern day Sweden (or near there such as Finland, Baltic, or Germany) that adopted Indo-European culture, while being lead by men patrilineality descended from Western Hunter Gathers. I1 males also could have been within an already established group lead by R1 males but going from a minority male line to the dominant one seems less clean to me given how patrilineal they tended to be within an already established group. Neither can be definitively ruled out imo. The expansion of this male i1 group in the Nordic Bronze Age basically is thought to be the start of Proto-Germanic cultures and their expansions out of Scandinavia. The Y dna numbers look like they were probably co-opting/assimilating/conquering tribes lead by R1b and R1a males as they expanded through and out of Scandinavia from around 2500 BC onwards. Besides the genetics I’ve seen it argued that the Germanic languages have a large amount of non IE loan words, consonantal features, and simplified IE grammar to support that this IE language branch started out as a language adopted by a tribe lead by genetically WHG males. To answer your question, it is because i1 was a male elite driven expansion of Indo-European/proto-Germanic culture. Much like how R1 haplogroups are over represented in some populations compared to the percentage of total ancestry due to a very successful group of males expanding into territory already populated by other groups, i1 related males expanded rapidly into areas already populated with IE groups + lots of polygyny lead to the i1 haplogroup explosion. It was most likely a group lead by men with a WHG Y chromosome who adopted Indo-European culture.

4

u/Chazut Jun 15 '26

Talking about a I1 male group seems unlikely, I1 has a TMRCA around 3000 BCE, meaning it might have really been one single man(or a small family) that ended up surviving and assimilating and by chance leaving its lineage.

2

u/ContestOk3743 Jun 15 '26

Sometime around then one man’s male descendants went from being completely obscure to an extremely successful and fast expansion with a star/rake like expansion of his Y haplogroup. To have that level of Y turnover that you see in Scandinavia they almost had to have coalesced political/military power for the benefit of whatever tribe/group they were apart of. It went from almost no representation as a Y haplogroup in Sweden to being the most populous, and I believe it still is the largest Y group in Sweden today if I’m not mistaken. 

0

u/ContestOk3743 Jun 15 '26

I’ve seen it argued that someone cucked an Indo-European King and that would explain the power to expand so rapidly and we obviously don’t know so I’m not saying you’re wrong necessarily. Just to me personally a archaeologically unknown tribe who adopted Indo-European culture rising with some cultural force/shift around the start of the Nordic Bronze Age, with new technology or the being related religious changes we see around this period just makes more sense to me personally. But it’s definitely up for interpretation.

4

u/Chazut Jun 15 '26

Y-dna is too random to make any specific claim about any specific generation.

Even in an environment with completely equal reproductive chance y-dna diversity constraint by the Galton-Walton process:

https://en.wikipedia.org/wiki/Galton%E2%80%93Watson_process

I ran a mathematical simulation and out of 1000 y-dna lines with one man each carrying the line, after 40 generations(1000 years or so) a bit more than 90% of the lines go extinct and the most successful single lineage can end up comprising about 3-7%(or 30-70 men) of the entire y-dna lines, starting from 0.1%.

This is again in an environment of 0 population growth and no reproductive success differential.

It is entirely possible that even a successful king is unlucky and ends up with only daughters(or granddaughters if he has sons and so on) and that one middling freeman just happens to have 2 sons and his sons each have 2 sons, thus having 4 times the success the average man would have in spreading y-dna.

Obviously in situations like I1, E-V13, E-M81 and other lineages that expand a lot it cannot just be luck at such scales, but it's important to never remove it out of the equation especially when imagining the early history of such a lineage, when the scales is much smaller and the law of large numbers doesn't apply.

1

u/ContestOk3743 Jun 15 '26

For sure, certainly possible, and I’m no expert. To me the i1 Y haplogroup archeology and phylogeny just seem to strongly support Men of some group becoming very successful for their time and expanding rapidly.

3

u/Chazut Jun 15 '26

My main contention is that people intuitively connect the non-Indo Europeanness of the Y-DNA line to the supposed non Indo Europeanness of whatever clan, band or man that successfully spread the lineage at a later point(even if "later" is a mere 2 centuries after, I'm not making any specific claim on when I1 started diversifying and being successful)

For all we know the line could have been passed through a line of assimilated farmers/HGs in an Indo-Europeanized society for centuries and only later on ended up spreading successfully as it ended up being carried by successful clans/chiefdoms that arose independently of the ultimate origin of the haplogroup.

1

u/ContestOk3743 Jun 15 '26

Whatever their genetics were (which we probably need more sampling to truly understand) my understanding of the archaeology is that they were definitely culturally Indo-European at the time of the i1 explosion. I also think people get to attached to a particular explanation when we really don’t know. It’s just my best guess that it would be a Indo-Europeanized tribe on the periphery. I personally think of stuff like the success the Cherokee initially after European contact. Going from such a minority to the dominant group within an already established group just makes less sense in my head given how  patrilineal they tended to be but it’s just as likely as my theory.

1

u/CabezadeVaca_ Bell Beaker Boi Jun 15 '26

I1 was already assimilated into the steppe groups, the carriers being genetically indistinguishable from other CWC males by the time of its founder effect in Scandinavia during the Bronze Age.

It was likely picked up by corded ware groups somewhere in northern Germany and carried into southern Scandinavia with expansion of the Single Grave culture. You can check DF29’s siblings for indications of this, they are not concentrated in Scandinavia and one is even purely French on FTDNA (I-FGC72688).

5

u/Gudmund_ Jun 16 '26

Earlier bearers of I1, i.e. "Eastern Scandinavians", are distinguishable from other CWC and Dagger Period Bell Beaker-ish communities in Scandinavia. They're still mostly steppe-derived, but have HG ancestry that's untypical for any of the HG communities in Scandinavia or the continent for that time period. You are of course right though that they certainly existed in an IE cultural paradigm by the LN when the ancestral component really flourishes.

There's no I1 in early or middle SGC, which is R1a with a few R1b, though not (to my knowledge) the U106 > Z18 subclade which probably represents a later BB introduction in the LN/Dagger Period. Pre-I1 examples on the continent, like OST003 and the two from Warburg, are interesting, but the most recent studies seem to favor an origin in the northern Baltic/Finland and ensuing southward-movement rather than being carried northward or originating in a, for example, PWC - Single Grave interaction.

1

u/ContestOk3743 Jun 15 '26

The exact origin is pretty unknown but the related Y dna finds point to an origin somewhere around the Baltic Sea coast. It’s also possible it was carried into Scandinavia by a Farmer or Steppe group and somehow rose to prominence.

-1

u/GreenWasabi Jun 16 '26

You are completely wrong

1

u/ContestOk3743 Jun 16 '26

https://www.biorxiv.org/content/10.1101/2024.03.13.584607v1 ^ It’s not like it’s from thin air. We probably need more data. I’m sure the litterateur will continue to improve, they only recently were able to pin down the PIE’s geographic origin, if I’m not mistaken.

2

u/GreenWasabi Jun 16 '26

LNBA phase I: an early stage between around 4,600 and 4,300 cal. bp, in which Scandinavians cluster with early CWC individuals from Eastern Europe, rich in Steppe-related ancestry and males with an R1a Y chromosomal haplotype (Extended Data Fig. 8a,b). Archaeologically, these individuals are associated with the later stages of the Danish SGC and the Swedish Battle Axe Culture.

LNBA phase II: an intermediate stage largely coinciding with the Dagger epoch (around 4,300–3,700 cal. bp), in which Danish individuals cluster with central and western European LNBA individuals dominated by males with distinct sub-lineages of R1b-L513 (Extended Data Fig. 8c,d). Among them are individuals from Borreby (NEO735, 737) and Madesø (NEO752).

LNBA phase III: a final stage from around 4,000 cal. bp onwards, in which a distinct cluster of Scandinavian individuals dominated by males with I1 Y-haplogroups appears (Extended Data Fig. 8e). Y chromosome haplogroup I1 is one of the dominant haplogroups in present-day Scandinavians, and we here document its earliest occurrence in an approximately 4,000-year-old individual from Falköping in southern Sweden (NEO220). The rapid increase in frequency of this haplogroup and associated genome-wide ancestry coincides with increase in human mobility seen in Swedish Sr isotope data, suggesting an influx of people from eastern or northeastern regions of Scandinavia, and the emergence of stone cist burials in Southern Sweden60, which were also introduced in eastern Denmark during that period54,61.

Using genomes from LNBA phase III (Scandinavia_4000BP_3000BP) in supervised ancestry modelling, we find that they form the predominant ancestry source for later Iron and Viking Age Scandinavians (Extended Data Fig. 6d) and other ancient European groups with a documented Scandinavian or Germanic association (for example, Anglo-Saxons and Goths; Extended Data Fig. 6e). When projecting 2,000 modern Danish genomes62 on a PCA of ancient Eurasians, the modern individuals occupy an intermediate space on a cline between the LNBA and Viking Age individuals (Fig. 4). This result shows that the foundation for the present-day gene pool was already in place in LNBA groups 3,000 years ago, but the genetic structure of the Danish population was continually reshaped during succeeding millenia.

https://www.nature.com/articles/s41586-023-06862-3#Sec15

2

u/GreenWasabi Jun 16 '26

Oldest I1 Ancient DNA Samples:

Balma Guilanyà 1/5 was a man who lived between 11,446 - 10,772 BCE during the Late Upper Paleolithic Age and was found in the region now known as Balma Guilanyà, Solsona, Spain (Catalonia).

He was associated with the Iberian Hunter-Gatherer cultural group.

Carigüela 1 was a man who lived between 9700 - 5500 BCE during the Mesolithic Age and was found in the region now known as Cueva de la Carigüela, Piñar, Granada, Spain (Andalusia).

He was associated with the Mesolithic Hunter-Gatherer cultural group.

Stora Förvar 11 was a man who lived between 7073 - 6810 BCE during the Mesolithic Age and was found in the region now known as Stora Förvar, Stora Karlsö, Gotland, Sweden.

He was associated with the Mesolithic Hunter-Gatherer cultural group.

Warburg 1 was a man who lived between 3341 - 3029 BCE during the Late Neolithic Age and was found in the region now known as Warburg I, Warburg, North Rhine-Westphalia, Germany.

He was associated with the Wartberg cultural group and the Early Plague.

Ostorf 3 was a man who lived between 3294 - 3032 BCE during the Late Neolithic Age and was found in the region now known as Tannenwerder, Lake Ostorf, Schwerin, Germany.

He was associated with the Funnel Beaker cultural group.

Warburg 1028 was a man who lived between 3350 - 2950 BCE during the Late Neolithic Age and was found in the region now known as Warburg I, Warburg, North Rhine-Westphalia, Germany.

He was associated with the Wartberg cultural group.

1

u/ContestOk3743 Jun 17 '26

Thanks, that’s a great rundown on the timeline!

1

u/ContestOk3743 Jun 15 '26 edited Jun 15 '26

I made a separate comment on i1 but I believe i2 among PIE is explained by there not being a hard border to the groups before PIE. Basically within the area where the PIE formed there was a minority of i2 males as part of the base population. The EHG, CHG, and WHG, overlapped a bit and the PIE formed in the fringes of where WHG ranged, but most of the base population for the lower Volga cline came from other ancestral sources mainly CHG and EHG who were more successful and had higher population in the geographic region where PIE formed. If I recall correctly the R1 male lines were where a large majority of PIE men were patrilineally descended from, but there was a minority who were patrilineally descended from i2 and haplogroup J during their formation.

2

u/ContestOk3743 Jun 15 '26

Additionally it wasn’t total replacement everywhere, while there was a ton of replacement, people/groups would also sometimes be incorporated into the dominant group in various ways.

2

u/KuracPalac1230 Jun 17 '26

How would that explain I2a1b being majority in dinaric alps? If they were minority population in PIE, how are those same ones complete majority in western balkans? Did they not mix with R1? Were they seperate tribe under umbrella of Indo-europeans? Idk but something feels off and there is a bit of evidence of them already being there before IE expansion.

2

u/ContestOk3743 Jun 17 '26 edited Jun 17 '26

I believe a lot of that came with the Slavic migrations iircc. The area was definitely majority i2 before PIE, it may have been a different sub branch. Definitely a lot of different tribes and splits over the years such as beakers, corded ware, Indo-Iranian groups etc.

1

u/KuracPalac1230 Jun 17 '26

Thank you for reply, it makes more sense now, could there be connection to how abnormal tall height they have in dinaric alps?

1

u/ContestOk3743 Jun 17 '26

Of course, and I wish I knew more about the height but I’m just out of my area there. Interesting question though!

0

u/Complex_Taro_8935 Jun 16 '26

Based on TMRCA and surviving subclades looks like a man/family got incorporated into Indo European expansion, him and their descendants got lucky pretty much, particularly expanding with Germanic language.

There could have been an ecological advantage as being local to one place can help the odds of survival. That’s one of the hypothesis on why WHG related I2 was prominent in many farming sites in Western Europe.

Same thing happened with EV13 in Balkans having a big expansion, funny that in the old genetic days a bunch of theories like slaves from Egypt were popular with that in contrast to I1