The Persian Gulf is just the flooded part of Tigris/Euphrates rivers valley.
During the last glacial period, it was a flood plain like the modern Iraqi one.

REFERENCES :
Hallast, P., Agdzhoyan, A., Balanovsky, O. et al. A Southeast Asian origin for present-day non-African human Y chromosomes. Hum Genet (2020). https://doi.org/10.1007/s00439-020-02...

Grant, K., Rohling, E., Ramsey, C. et al. Sea-level variability over five glacial cycles. Nat Commun 5, 5076 (2014). https://doi.org/10.1038/ncomms6076


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