If you assumed the creatures from which humans descended took their first steps on land, new research suggests it's time to think again.
University of Chicago scientists published their findings this week in the online version of the journal the Proceedings of the National Academy of Sciences.
The researchers closely watched lungfish and noticed that the fish use their stringy back limbs to propel themselves along the bottoms of streams. Lungfish are freshwater fish closely related to the original four-limbed tetrapods and do not have fingers or toes. This showed researchers that humanity's ancestors likely walked underwater before making the transition to land and developing digits, the International Business Times reports.
"This is another powerful example of exaptation," an assistant professor at Howard University, Rui Diogo, who was not associated with the study, told the International Business Times. "By showing this, the paper helps to better understand one of the most dramatic evolutionary transitions in biology: the origin of tetrapods, and the transformation from fins to limbs."
How does this change your view of evolution? Sound off below and on our WNWO Facebook page.
Want to take a closer look at lungfish? Watch this Animal Planet clip showing how lungfish can breathe air outside of the water!