Flann Fina
Regular Member
- Messages
- 75
- Reaction score
- 43
- Points
- 18
- Location
- Florida
- Ethnic group
- English, Scottish & Irish
- Y-DNA haplogroup
- I1-FT80630
- mtDNA haplogroup
- H1e2
For those who are I1-M253 there’s a very interesting article that may be of interest to you.
See:
From Stone to Bronze in prehistoric Scandinavia
Posted by Genomic Atlas on 15 July, 2022
https://genomicatlas.org/2022/07/15...developments-in-scandinavian-archaeogenetics/
Here is an excerpt:
The origin of haplogroup I1-M253
Haplogroup I1, also known as I-M253, has puzzled experts and amateurs alike for a long time. Why was it so rare prior to the Nordic Bronze Age? How did it become the dominant Y-DNA haplogroup in Scandinavia? Is it native to Scandinavia, or did it get there far later than most would assume? These are questions that, with the help of old and new studies, are answerable. At least some of them.
I1 has an estimated TMRCA (Time To Most Recent Common Ancestor) of 4600 ybp, or 2600 BC. What this means is that all living I1 men descend from just one man who lived roughly 4600 years ago. The haplogroup has a dramatic, shallow phylogenetic structure, which strongly suggests that it was heavily bottlenecked before it expanded rapidly. Furthermore, it has an exceptional >310 unique mutations, a telltale sign of it being in a severely bottlenecked state before its explosive expansion during the Bronze Age, Iron Age and Viking Age. The phylogenetic tree below further illustrates the shallow phylogeny of the I1 haplogroup, which is a strong indicator of a rapid, recent growth:
Phylogeny of Y-chromosome haplogroups from Batini et al. (2015)
While I1 itself is 27,000 years old, it underwent a crash in terms of frequency and subclade diversity to the point where it was almost extinct. This long bottleneck lasted approximately between 25,000 BC and 2600 BC. During the bottleneck event, I1 must have been limited to a remarkably small group of men, perhaps at times even a single man. This is visible in the phylogenetic structure of I1, and has led to much speculation about where I1 managed to survive for so long before finally making a “comeback” and becoming a common Y-DNA haplogroup.
Sometimes, when an ancient sample is derived for some of the SNPs that define I1, but also ancestral for many other SNPs that define the haplogroup, that sample is labelled I-Z2699*/pre-I1. What this means is that the sample represents a position in the phylogenetic tree that can be described as being between I and I1, essentially on its way to developing into what we now know as I1. It was from one of those pre-I1 samples that the progenitor of all later I1 descended before that man ended the genetic bottleneck.
So far, the only pre-I1/I-Z2699* found anywhere in Northern Europe is the Mesolithic Scandinavian-Hunter-Gatherer sample SF11 (Stora Förvar 11) from what is now Gotland in Sweden. SF11 is derived for some of the SNPs that define I1, but also ancestral for some of them. In order to know with certainty that the progenitor of later I1 men had his deep origins in a SHG population, more pre-I1 samples from such a population is needed. Until then, we can only guess.
After SF11 who is dated to around 6500 BC, there is a large gap in time where no I1 samples are found in Scandinavia. Almost all of the Mesolithic samples from Scandinavia belong to haplogroup I2, and samples from Middle Neolithic Scandinavia (Funnelbeaker, Battle Axe, Pitted Ware) have yielded zero samples belonging to haplogroup I1. It is only in Late Neolithic Scandinavia, right on the verge of the Bronze Age, that the first I1 samples are found and the bottleneck appears to have ended. At the point where we find these early I1 carriers in the ancient DNA record, near Falköping in Sweden, they are already heavily admixed with Corded Ware-derived populations and derive the bulk of their ancestry from the steppe. Therefore, it is hard to figure out how and when I1-carriers first encountered and mixed with Corded Ware peoples. Future samples may help in solving this mystery. Until then, based on the data, there are three possible and realistic scenarios:
Upcoming samples from Mesolithic and Middle Neolithic Scandinavia may be able to tell us more about the ultimate origin of haplogroup I1. In the meantime, thanks to Allentoft’s new study, we know that I1 underwent a sharp, dramatic rise in frequency during the Nordic Bronze Age and spread when Germanic tribes migrated out of Scandinavia into Continental Europe. Until we get samples from hunter-gatherers from more remote regions of Mesolithic and Neolithic Scandinavia, the deep origins of I1 will likely remain shrouded in mystery.
Interestingly, studies like Patterson et al. 2022, Papac et al. 2021 and Rohrlach et al. 2021 found zero samples of haplogroup I1 in Bronze Age Continental Europe, despite sequencing many hundreds of samples from a very wide range of sites and countries all across Continental Europe.
See:
From Stone to Bronze in prehistoric Scandinavia
Posted by Genomic Atlas on 15 July, 2022
https://genomicatlas.org/2022/07/15...developments-in-scandinavian-archaeogenetics/
Here is an excerpt:
The origin of haplogroup I1-M253
Haplogroup I1, also known as I-M253, has puzzled experts and amateurs alike for a long time. Why was it so rare prior to the Nordic Bronze Age? How did it become the dominant Y-DNA haplogroup in Scandinavia? Is it native to Scandinavia, or did it get there far later than most would assume? These are questions that, with the help of old and new studies, are answerable. At least some of them.
I1 has an estimated TMRCA (Time To Most Recent Common Ancestor) of 4600 ybp, or 2600 BC. What this means is that all living I1 men descend from just one man who lived roughly 4600 years ago. The haplogroup has a dramatic, shallow phylogenetic structure, which strongly suggests that it was heavily bottlenecked before it expanded rapidly. Furthermore, it has an exceptional >310 unique mutations, a telltale sign of it being in a severely bottlenecked state before its explosive expansion during the Bronze Age, Iron Age and Viking Age. The phylogenetic tree below further illustrates the shallow phylogeny of the I1 haplogroup, which is a strong indicator of a rapid, recent growth:
Phylogeny of Y-chromosome haplogroups from Batini et al. (2015)While I1 itself is 27,000 years old, it underwent a crash in terms of frequency and subclade diversity to the point where it was almost extinct. This long bottleneck lasted approximately between 25,000 BC and 2600 BC. During the bottleneck event, I1 must have been limited to a remarkably small group of men, perhaps at times even a single man. This is visible in the phylogenetic structure of I1, and has led to much speculation about where I1 managed to survive for so long before finally making a “comeback” and becoming a common Y-DNA haplogroup.
Sometimes, when an ancient sample is derived for some of the SNPs that define I1, but also ancestral for many other SNPs that define the haplogroup, that sample is labelled I-Z2699*/pre-I1. What this means is that the sample represents a position in the phylogenetic tree that can be described as being between I and I1, essentially on its way to developing into what we now know as I1. It was from one of those pre-I1 samples that the progenitor of all later I1 descended before that man ended the genetic bottleneck.
So far, the only pre-I1/I-Z2699* found anywhere in Northern Europe is the Mesolithic Scandinavian-Hunter-Gatherer sample SF11 (Stora Förvar 11) from what is now Gotland in Sweden. SF11 is derived for some of the SNPs that define I1, but also ancestral for some of them. In order to know with certainty that the progenitor of later I1 men had his deep origins in a SHG population, more pre-I1 samples from such a population is needed. Until then, we can only guess.
After SF11 who is dated to around 6500 BC, there is a large gap in time where no I1 samples are found in Scandinavia. Almost all of the Mesolithic samples from Scandinavia belong to haplogroup I2, and samples from Middle Neolithic Scandinavia (Funnelbeaker, Battle Axe, Pitted Ware) have yielded zero samples belonging to haplogroup I1. It is only in Late Neolithic Scandinavia, right on the verge of the Bronze Age, that the first I1 samples are found and the bottleneck appears to have ended. At the point where we find these early I1 carriers in the ancient DNA record, near Falköping in Sweden, they are already heavily admixed with Corded Ware-derived populations and derive the bulk of their ancestry from the steppe. Therefore, it is hard to figure out how and when I1-carriers first encountered and mixed with Corded Ware peoples. Future samples may help in solving this mystery. Until then, based on the data, there are three possible and realistic scenarios:
- I1 was present as a very rare haplogroup among Pitted Ware hunter-gatherers in Scandinavia and encountered the Battle Axe people and mixed with them (or mixed with the FBC people before encountering the BAC)
- I1 was picked up and assimilated by Single Grave people somewhere in Zealand or Scania
- I1 was brought by the Corded Ware-derived groups from somewhere in Poland where it originally got into the Corded Ware population from a Globular Amphora source
Upcoming samples from Mesolithic and Middle Neolithic Scandinavia may be able to tell us more about the ultimate origin of haplogroup I1. In the meantime, thanks to Allentoft’s new study, we know that I1 underwent a sharp, dramatic rise in frequency during the Nordic Bronze Age and spread when Germanic tribes migrated out of Scandinavia into Continental Europe. Until we get samples from hunter-gatherers from more remote regions of Mesolithic and Neolithic Scandinavia, the deep origins of I1 will likely remain shrouded in mystery.
Interestingly, studies like Patterson et al. 2022, Papac et al. 2021 and Rohrlach et al. 2021 found zero samples of haplogroup I1 in Bronze Age Continental Europe, despite sequencing many hundreds of samples from a very wide range of sites and countries all across Continental Europe.
