" African Introgression
One particular usage of the f-statistics in our study is to test for African introgression for each of the Italian samples with f3(Test sample; CEU, Yoruba) and f4(Test sample, CEU; Yoruba, Onge). The f3 statistic tests whether across the genome, the allele frequency of the test sample is intermediate between those of Finnish and Yoruba, which is unexpected if the test sample, presumably of primarily European ancestry, forms a clade with Finnish with regard to Yoruba in the phylogenetic tree at all genomic loci. Therefore, a significantly negative f3 statistic provides evidence for African ancestry in the test sample. (In this particular application, we used the imputed diploid genotype data without the “inbreed: YES” option, because qp3Pop cannot calculate f3 when (1) the target is a single individual and (2) the “inbreed: YES” option.) For the f4 statistic described above, under the assumption that chimpanzee is an outgroup, a significant positive score suggests more allele sharing between the ancient Italian individual (test sample)and Yoruba than between CEU and Yoruba, thus pointing to African introgression in the Italian individual. This test alone does not exclude the possibility of gene flow in the reverse direction, i.e., from the Italian sample to Yoruba, but this alternative scenario is unlikely given current knowledge about the demographic history of Yoruba and does not produce a significant f3 statistic as formulated above.Taken together, significant signals in both tests provide strong evidence for African introgression, which is observed for 8 of the 127 Italian samples, including R475 from Iron Age, R80 and R132 from Imperial period (Fig. S23). We obtained qualitatively similar results by substituting Yoruba by Mota (an ancient African found in Ethiopia dated to ~2500 BCE) or Morocco_Iberomaurusian (hunter-gatherers from Morocco dated to 13,000-10,000 BCE) for the African population, and Onge by Papuan for the outgroup. We note that using Yoruba, Mota or Morocco hunter-gatherers as the representative African population is conservative for detecting more recent North African ancestry. We are using conservative estimates, since
data is not available from relevant, contemporaneous (e.g. Iron Age and Imperial) populations, such as Carthagians. For instance, qpAdm analysis using Late Neolithic individuals from Morocco models R475 as approximately 53% Late Neolithic Moroccan, 30% Italian Copper Age and 16% Steppe Eneolithic, whereas the estimates below show Morocco Iberomaurusian and Yoruban to be around 8 - 10% ancestry proportion for this individual. The African introgression signal we observe in the time series may reflect increased seafaring in the Mediterranean prior to Iron Age.Phoenician seafaring prowess had resulted in a network of colonies 20 across North Africa, engaged in trans-Mediterranean trade. Carthage, which began as a Phoenician trade colony in 1234 BCE, became the dominant naval state in the Mediterranean, with territory spanning
North African, Sardinia, Sicily, and Iberia (26). Egypt had been involved in trans-Mediterranean and trans-Saharan trade networks for over a millennium by the start of the Iron Age. And trans-Saharan trade routes, made easier by a greener, less arid Sahara than today, connected the states and communities of North Africa and the Mediterranean with their Saharan and Sub-Saharan counterparts (86). "
I‘m not sure whether I properly understood what this data says. Does this study suggest that Etruscans, Italics had North African or even SSA admixture or does it refer to Cartheganian/ North African migrants in Rome? I read many afrocentric websites that claim that Etruscans and original Romans were black. Please, can someone translate it in more layman- language. There are people who also claim that Etruscans originally came from Carthage via Anatolia, Troy due to the Etruscan female with 53% Morrocan mix.