Post by djoser-xyyman on Mar 15, 2019 21:24:12 GMT -5
People from Ibiza: an unexpected isolate in the Western Mediterranean -Simone Andrea Biagini
Abstract
In this study, we seek to understand and to correlate the genetic patterns observed in the population of the island of Ibiza in
the Western Mediterranean basin with past events. Genome-wide genotypes of 189 samples representing 13 of 17 regions in
Spain have been analyzed, in addition to 105 samples from the Levant, 157 samples from North Africa, and one ancient
sample from the Phoenician Cas Molí site in Ibiza. Before the Catalans conquered the island in 1235 CE, Ibiza (Eivissa) had
already been influenced by several cultures, starting with the Phoenicians, then the Carthaginians, followed by the
Umayyads. The impact of these various cultures on the genetic structure of the islanders is still unexplored. Our results show
a clear distinction between Ibiza and the rest of Spain. To investigate whether this was due to the Phoenician colonization or
to more recent events, we compared the genomes of current Ibizans to that of an ancient Phoenician sample from Ibiza and to
both modern Levantine and North African genomes. We did not identify any trace of Phoenician ancestry in the current
Ibizans. Interestingly, the analysis of runs of homozygosity and changes in the effective population size through time support
the idea that drift has shaped the genetic structure of current Ibizans. In addition to the small carrying capacity of the island,
Ibiza experienced a series of dramatic demographic changes due to several instances of famine, war, malaria and plague that
could have significantly contributed to its current genetic differentiation.
A total of 41 samples failed the
genotyping process, leading to 122 remaining individuals
(Supplementary Table S1). An Identity-by-descent (IBD)
analysis was performed in order to unveil close relatedness
between the donors. Two pairs of samples, both from the
island of Ibiza, did not pass the test. Eventually, a total of
120 samples were retained (data available at https://figsha
re.com/articles/People_from_Ibiza_dataset/7162025). Out
of the 633,995 SNPs interrogated by the array, a different
number of variants per batch passed the genotyping process (Supplementary Figure S1).
figshare.com/articles/People_from_Ibiza_dataset/7162025
v
Abstract
In this study, we seek to understand and to correlate the genetic patterns observed in the population of the island of Ibiza in
the Western Mediterranean basin with past events. Genome-wide genotypes of 189 samples representing 13 of 17 regions in
Spain have been analyzed, in addition to 105 samples from the Levant, 157 samples from North Africa, and one ancient
sample from the Phoenician Cas Molí site in Ibiza. Before the Catalans conquered the island in 1235 CE, Ibiza (Eivissa) had
already been influenced by several cultures, starting with the Phoenicians, then the Carthaginians, followed by the
Umayyads. The impact of these various cultures on the genetic structure of the islanders is still unexplored. Our results show
a clear distinction between Ibiza and the rest of Spain. To investigate whether this was due to the Phoenician colonization or
to more recent events, we compared the genomes of current Ibizans to that of an ancient Phoenician sample from Ibiza and to
both modern Levantine and North African genomes. We did not identify any trace of Phoenician ancestry in the current
Ibizans. Interestingly, the analysis of runs of homozygosity and changes in the effective population size through time support
the idea that drift has shaped the genetic structure of current Ibizans. In addition to the small carrying capacity of the island,
Ibiza experienced a series of dramatic demographic changes due to several instances of famine, war, malaria and plague that
could have significantly contributed to its current genetic differentiation.
A total of 41 samples failed the
genotyping process, leading to 122 remaining individuals
(Supplementary Table S1). An Identity-by-descent (IBD)
analysis was performed in order to unveil close relatedness
between the donors. Two pairs of samples, both from the
island of Ibiza, did not pass the test. Eventually, a total of
120 samples were retained (data available at https://figsha
re.com/articles/People_from_Ibiza_dataset/7162025). Out
of the 633,995 SNPs interrogated by the array, a different
number of variants per batch passed the genotyping process (Supplementary Figure S1).
figshare.com/articles/People_from_Ibiza_dataset/7162025
v
