Human Median Artery Evolution Mystery

In utero, a temporary vessel called the median artery runs down the arm to help supply the developing hand, and it usually disappears shortly after birth. But a 2020 study found that more adults are now retaining that artery, with the prevalence appearing to be far higher than it was in people born in the late 19th century. Researchers suggested this could reflect ongoing microevolution linked to genetic or developmental changes, but they did not pin down a single exact reason for the shift.

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