Clustering of 770,000 genomes reveals post-colonial population structure of North America

[techbeck]

Despite strides in characterizing human history from genetic polymorphism data, progress in identifying genetic signatures of recent demography has been limited. Here we identify very recent fine-scale population structure in North America from a network of over 500 million genetic (identity-by-descent, IBD) connections among 770,000 genotyped individuals of US origin. We detect densely connected clusters within the network and annotate these clusters using a database of over 20 million genealogical records. Recent population patterns captured by IBD clustering include immigrants such as Scandinavians and French Canadians; groups with continental admixture such as Puerto Ricans; settlers such as the Amish and Appalachians who experienced geographic or cultural isolation; and broad historical trends, including reduced north-south gene flow. Our results yield a detailed historical portrait of North America after European settlement and support substantial genetic heterogeneity in the United States beyond that uncovered by previous studies.

 

Following the arrival of Columbus and his contemporaries, population expansion in the Americas has proceeded at an exceptionally rapid pace, with factors such as war, slavery, disease and climate shaping human demography. Recent genetic studies of the United States and North America have drawn insights into ancient human migrations1,2 and population diversity in relation to global population structure3,4,5,6,7,8,9,10,11. These insights have been primarily drawn from modelling variation in allele frequencies (for example, refs 11, 12, 13, 14, 15), which typically diverge slowly. This may in part explain why these studies have revealed little about population structure on the time-scale of post-European colonization (1500–2000 AD) that is not directly tied to pre-Columbian diversity within the Americas nor to ‘Old World’ populations outside the United States.

 

In this study, we analyse genome-wide genotype data from over 777, 000 primarily US-born individuals. Among all pairs of individuals, we identify genetic connections defined by sharing a recent common ancestor; when these connections are aggregated into a network, our computational methods reveal densely connected clusters, in which the members of each cluster are subtly more related to each other. Using a unique collection of 20 million user-generated genealogical records, we annotate these densely connected clusters to identify the putative historical origins of such population substructure, and to infer temporal and geographic patterns of migration and settlement. With much greater granularity than previously possible, our analyses demonstrate the impact of subtle, complex demographic forces in shaping the patterns of genetic variation among contemporary North Americans.

 

More....

https://www.nature.com/articles/ncomms14238#f2

Edited January 26, 2018 by techbeck
removed the marketing referral on the link

[xendrome]

Nice paywall on the map, can't fully read or zoom in unless you pay $79

[DocM]

So it reports much of the upper Midwest & Great Lakes has an abundance of Finns, Swedes. Norwegians, Danes and French Canadians. 

 

You could walk outside and figure that out. Listen to many of us speak and you'd be sure of it. Rather distinctive dialects, especially in the exurbs and rural areas.

 

For free.

Edited January 26, 2018 by DocM

[Jim K Global Moderator]

9 minutes ago, xendrome said:

Nice paywall on the map, can't fully read or zoom in unless you pay $79

The Nature Communications publication is here...

https://www.nature.com/articles/ncomms14238

 

Can't really tell on my phone if the map is any better though.

[Steven P. Administrators]

All this is is a giant ad, I removed the referral part of the link from the OP but I question the value of this topic, it appears to be nothing more than a copy/paste for an advert for some ancestry website  

[techbeck]

13 minutes ago, Jim K said:

The Nature Communications publication is here...

https://www.nature.com/articles/ncomms14238

 

Can't really tell on my phone if the map is any better though.

Actually a better link.  Thanks

 

I updated the OP with the new link/info.  Map is also bigger in the link you provided. 

[techbeck]

26 minutes ago, DocM said:

You could walk outside and figure that out. Listen to many of us speak and you'd be sure of it. Rather distinctive dialects, especially in the exurbs and rural areas.

Considering people cannot be everywhere at once, a person cannot just walk outside and figure it out.  And not everyone knows what certain dialects sound like and can distinguish what is what.

32 minutes ago, xendrome said:

Nice paywall on the map, can't fully read or zoom in unless you pay $79

I didnt have a problem reading the link so I didnt click on the image.  I updated the OP with a better source Jim K provided.