How did Sardinians remain so genetically isolated?

[Sikeliot]

How did Sardinia remain so genetically isolated? Especially from the Neolithic migrations that became such an important part of the genetic makeup of all of the other islands in the Mediterranean, especially Sicily, Crete, and even to an extent Corsica.

Look at where it is.

http://www.letsdoitworld.org/system/files/med2.gif

How did the West Asian Neolithic genetic component completely bypass Sardinia, but Corsicans have it in similar amounts to northern Italians? For Neolithic settlers to arrive in Corsica, they'd have had to go right past Sardinia to get there.

How did the Phoenicians and Romans have little to no genetic impact on Sardinians despite having both been present on the island at different times? Essentially how did an island that is in the middle of the Mediterranean somehow avoid all of the genetic influences that the other islands around it have?

[kabeiros]

For Neolithic settlers to arrive in Corsica, they'd have had to go right past Sardinia to get there. not really, they could have gone there directly from northern Italy

[Sikeliot]

not really, they could have gone there directly from northern Italy

So you think Corsicans are descended in large part directly from Italian settlers, and that it's not like the island was settled significantly prior to that?

[Anusiya]

Sardinians don't belong to the greater rest of the italic peoples, that's highly likely.

[Sikeliot]

Sardinians don't belong to the greater rest of the italic peoples, that's highly likely.

I just don't know how they avoided getting West Asian genetic influence and Northern European. Even Sicilians and Cretans have more Northern European shift than do Sardinians. And their geographic location makes it seem difficult for them to have remained so isolated!

[kabeiros]

Have you consider inbreeding?

[Anusiya]

I just don't know how they avoided getting West Asian genetic influence and Northern European. Even Sicilians and Cretans have more Northern European shift than do Sardinians. And their geographic location makes it seem difficult for them to have remained so isolated!

Quite possibly they always lived in a part of the island that was not in a way of a trade route, or other important point of interest for noone. Lucky them!

[Anglojew]

How did Sardinians remain so genetically isolated?

Simple, have you seen their women?

(That's a joke).

[Ira di Dio]

So you think Corsicans are descended in large part directly from Italian settlers
It's not what he thinks, it's what did occur.

[Peyrol]

These parts are interesting:




The language (or the languages) spoken in Sardinia during the bronze age is unknown . According with some reconstructions the "Proto-Sardinian language" was a derivate of the Basque language with similarities with the ancient Iberian . Other scholars believe that there were various linguistic areas (two or more), possibly pre-indoeuropeans and indoeuropeans.



Sardinians share with the inhabitants of Japanese island of Okinawa the highest rate of centenarians in the world (22 centenarians/100,000 inhabitants).

[Prince Carlo]

According to Razib Khan the malaria has kept away invaders.

[Peyrol]

Also this is interesting:

http://upload.wikimedia.org/wikipedia/commons/4/48/Haplogroup_I.png

[zlakopistou]

It's not really surprising, however, according to Dienekes, Sardinians have African ancestry:


For Sardinians:

We detect a very small proportion of Sub-Saharan African ancestry in Sardinians, which our ALDER tests identified as admixed (Table 1; Figure 3A). To investigate further, we computed weighted LD curves with Sardinian as a test population and all pairs of the HapMap CEU, YRI and CHB populations as references (Table 2). We observed an abnormally large amount of shared long-range LD in chromosome 8, likely do to an extended inversion segregating in Europeans (PRICE et al. 2008), so we omitted it from these analyses. The CEU–YRI curve has the largest amplitude, suggesting both that the LD present is due to admixture and that the small non- European ancestry component, for which we estimated a lower bound of 0.6+/-0.2%, is from Africa. The existence of a weighted LD decay curve with CHB and YRI as references provides further evidence that the LD is not simply due to a population bottleneck or other non-admixture sources, as does the fact that our estimated dates from all three reference pairs are roughly consistent at about 40 generations (1200 years). Our findings thus confirm the signal of African ancestry in Sardinians reported in MOORJANI et al. (2011). The date, small mixture proportion, and geography are consistent with a small influx of migrants from North Africa, who themselves traced only a fraction of their ancestry ultimately to Sub-Saharan Africa, consistent with the findings of DUPANLOUP et al. (2004).

The estimation is between 0.6% and 1.3% African. That would equal to 3 to 6% North African ancestry. If the estimated age is real (sounds wrong with Mozabites' African ancestry), it fits very well several eras: Carthage, Roman Empire, early Christian era and finally the medieval Islamic era.

The dichotomy between the mountainous inlands and the malarian coasts, as suggested by someone sounds like a good barrier for the remaining invasions.

[Peyrol]

^

0,6-1,3 is trascurable. Even american anglosaxons have more SSA admisture than this.

[Sikeliot]

^

0,6-1,3 is trascurable. Even american anglosaxons have more SSA admisture than this.

If Sardinians get that much I'd like to see what Madeira Portuguese get.

[Kazuma]

Some time ago I read an article about an attitude known as "costante resistenziale sarda". It's a theory about the continuous struggle of sardinians against any invasion of foreigner people...something similar to basque.
Last, take a look at the territory of the centre sardinia. Mountain, mountain, hot summer and cold winter (for mediterraneum area obviously)... very different from sicily, more similar to calabria/abruzzo.

However I doubt of these studies...they change too quickly ;D

[Prince Carlo]

Actually this results came from Sardinian HGDP who are selected from few places. I wonder what would be the results with a wider range of samples.

[MM81]

Corsica has been a genoese territory for centuries. Their language sounds like a mix of tuscan and ligurian dialects. IMO, they're "expat" northern italians, with ligurian and tuscan roots. Sardinians are different. About haplogroup I, I read it's the oldest in Europe and it survived the R1 (a and b) "invasions" thanks to the isolation of the populations carrying it. Scandinavians, sardinians and people from the deepest Balkan area are the haplo I carryiers par excellance... Not a case. And, wait... Coon stated that nordids are depigmented mediterraneans (for environmental causes). Dinarids would be a variation of meds, too. Sardinians are in large majority ibero-insular, scandinavians nordids, balkanites dinarid... Oh my f....ng god!

[Sisak]

X5wiSsUPfjw

[Sisak]

http://www.youtube.com/watch?v=WgEeWs4fLVs&list=PL14523AA1547A292B&index=4&feature=plpp_video (http://www.youtube.com/watch?v=WgEeWs4fLVs&list=PL14523AA1547A292B&index=4&feature=plpp_video)