How Old is R1b-L21?

[Stevo]

By now most of us are familiar with FTDNA’s new Discover app that enables one to look up a reasonable age estimate of pretty much any Y-DNA haplogroup.

A couple of days ago I plugged L21 into Discover and got an age estimate of ~4000 years ago, ~1900 BC, with a 95% probability range of 2450-1350 BC.

I’m not sure what’s right for L21 exactly, but I think Discover’s estimate is a little too young. In fact, I’m sure that ~1900 BC estimate is too young, because I know there are radiocarbon dated ancient remains that are R1b-L21 that are older than that in the famous Olalde et al paper, “The Beaker phenomenon and the genomic transformation of northwest Europe”.

For example, sample I2565, known as “The Companion” because he was buried just three meters from the famous Amesbury Archer and is believed to be the Archer’s son because of an hereditary anomaly in the bones of their feet the two shared, was R1b-L21 and radiocarbon dated to 2470-2140 BC.

So we know L21 was already in existence by 2140 BC at the latest, and there may be an even older L21 in Olalde et al that I am forgetting.

Sadly, very sadly, Olalde et al weren’t able to get any DNA out of the celebrated Archer himself, more’s the pity. His results would have been something. But The Companion probably was his son, so it’s reasonable to conclude that the Archer was also R1b-L21.

So what do you all think? How old is L21?

Personally, I won’t be surprised if L21 turns up in Single Grave Corded Ware on the continent.

[Stevo]

Looking back at the L21+ results from Olalde et al, I see that sample I2457 was R1b-L21 and radiocarbon dated to 2480-2031. That’s in the same ballpark as sample I2565 that I mentioned in the last post above, which makes the argument stronger that L21 is older than Discover’s current estimate of ~1900 BC, but, to be fair, is within its 95% probability range of 2450-1350 BC, which is what you get when you add and subtract the plus or minus 550 years that comes with Discover’s ~1900 BC estimate.

In addition, Olalde et al features several radiocarbon dated DF13+ samples, two steps downstream of L21, that are a couple of centuries older than 1900 BC.

I’m not trying to criticize Discover, which is currently in beta anyway. What I’m doing is arguing that these ancient results show us a terminus ante quem for L21 of no later than 2140 BC, and within the range of 2480-2140 BC.

I’m hoping some future papers show L21 in Single Grave Corded Ware on the continent and push the age of L21 back to beyond 2500 BC.

[Stevo]

You know, it just crossed my mind that a lot of fairly recent FTDNA customers might not know what L21 is or that they are derived (positive) for it, even if they have had the excellent Big Y-700 test.

Nowadays L21 is just another SNP in a stack of SNPs leading up to one’s terminal SNP. It’s only those of us who’ve been around FTDNA and Y-DNA testing for awhile for whom L21 is still a big deal, especially those of us who were FTDNA customers back before the Big Y, back when each new Y-DNA SNP was a big discovery in its own right and would generate a stand alone test from FTDNA.

I remember when L21 represented a huge breakthrough for those of us of northwest European ancestry, especially for those of us of Irish and British Isles ancestry. It was back in 2008 that FTDNA began testing for it. I remember my excitement back then when I got my L21+ result.

[Stevo]

I was looking back through this old sub forum, which was started back when I was the head admin of the L21 Project, which came to be called the R L21 Plus Project.

To avoid any confusion, let me say that I no longer run that project. I gave it up years ago mainly because it had become too big (HUGE!) and unwieldy for my taste. I retreated to a handful of much smaller, more personal projects. I am very happy with them.

So, I cannot help you with the L21 Project, but I am very happy to discuss L21 with you and answer any questions I can.

[Stevo]

As of today FTDNA Discover says this about R-L21:

The R-L21 Story

R-L21's paternal line was formed when it branched off from the ancestor R-Z290 and the rest of mankind around 2650 BCE.

The man who is the most recent common ancestor of this line is estimated to have been born around 2550 BCE.

That makes a lot more sense than what it said back in July.

[Stevo]

The age of R1b-L21 is important, for one reason because of the perennial debate about whether or not L21 originated in the British Isles. Personally, I'm of the opinion that L21 is too old to have arisen in the Isles. We know from the excellent Olalde et al scientific paper, "The Beaker phenomenon and the genomic transformation of northwest Europe", that there was no R1b of any kind in Britain before the arrival of the Beaker people ~2400 BC. If L21 is about 250 years older than that, having arisen about 2650 BC, then it could not have arisen in the Isles.

The oldest British male Beaker remains in Olalde et al are already R1b-L21, and some of them are R1b-DF13, a couple of steps downstream of L21. For L21 to have arisen in Britain, its xL21 predecessors would have had to have been present: R1b-Z290 and its progenitor, R1b-P312. Where are they?

Feel free to disagree with me, but in order to do so in a reasonable way, you're going to have to show that L21 is younger than we currently think it is, and that its father SNP, Z290, was present in Britain before L21 appeared. Either that, or you're going to have to show that R1b-Z290, or at least R1b-P312, got to Britain much earlier than we currently believe that any kind of R1b did.

[Stevo]

First, we have the Brace et al paper, " Ancient genomes indicate population replacement in Early Neolithic Britain", which shows that the Mesolithic hunter-gatherer population of Britain was largely replaced around 4000 BC by Neolithic farmers from the Continent. Neither of those groups had any R1b of any kind and no steppe DNA. Then, sometime between 2400 and 2300 BC, the Neolithic farmer population of Britain was largely replaced by Beaker from the Continent, who carried both R1b-L21 and steppe DNA. We know about this second population turnover from Olalde et al, "The Beaker phenomenon and the genomic transformation of northwest Europe".

[Stevo]

FTDNA Discover says this about R1b-L21's immediate predecessor, R1b-Z290, today:

The R-Z290 Story

R-Z290's paternal line was formed when it branched off from the ancestor R-P312 and the rest of mankind around 2800 BCE.

The man who is the most recent common ancestor of this line is estimated to have been born around 2650 BCE.

As the archaeological and ancient genomic evidence now stand, that is definitely too early for Z290 to have been born in the British Isles or Ireland. If that date is about right, then Z290 was probably born on the Continent in the context of the Single Grave Corded Ware culture. 2650 BC is a bit too early for Beaker, which was derived from Single Grave Corded Ware anyway.

[Stevo]

Here's what FTDNA Discover says about R1b-L21 today:

The R-L21 Story


R-L21's paternal line was formed when it branched off from the ancestor R-Z290 and the rest of mankind around 2650 BCE.

The man who is the most recent common ancestor of this line is estimated to have been born around 2600 BCE.

So, that's the latest word from Discover on the likely age of R1b-L21. If that's about right, then L21 was probably born in the context of the Single Grave Corded Ware culture or possibly in very early Beaker, which was derived from Single Grave Corded Ware.

I'm guessing the locale was the Netherlands/NW Germany. L21 was brought to Britain by the Beaker Folk about 2400 BC.

[Stevo]

For example, sample I2565, known as “The Companion” because he was buried just three meters from the famous Amesbury Archer and is believed to be the Archer’s son because of an hereditary anomaly in the bones of their feet the two shared, was R1b-L21 and radiocarbon dated to 2470-2140 BC.

I have to post an update to the quote above. Yes, "The Companion" is R1b-L21, but the Archer was recently retested. The results were published in the recent Patterson et al paper, "Large-scale migration into Britain during the Middle to Late Bronze Age" (2021). As it turns out, the Companion and the Archer are not son and father.

Thought I should mention that by way of clarity. As I recall, the Archer was some kind of R1b-U152, but he supposedly belongs to a subclade rather too far downstream for his time period. I'll leave that for others to puzzle over.