Dikika Foot Anatomy Explained in New Science Advances Paper

The functional and evolutionary implications of primitive retentions in early hominin feet have been under debate since the discovery of Australopithecus afarensis. Ontogeny can provide insight into adult phenotypes, but juvenile early hominin foot fossils are exceptionally rare. The focus of this paper is a thorough analysis of a nearly complete, 3.32-million-year-old juvenile foot of A. afarensis (DIK-1-1f). The results show that juvenile A. afarensis individuals already had many of the bipedal features found in adult specimens. However, they also had medial cuneiform traits associated with increased hallucal mobility and a more gracile calcaneal tuber, which is unexpected on the basis of known adult morphologies. Selection for traits functionally associated with juvenile pedal grasping may provide a new perspective on their retention in the more terrestrial adult A. afarensis.

DeSilva, J.M., Gill, C.M., Prang, T.C., Bredella, M.A., Alemseged, Z. 2018. A nearly complete foot from Dikika, Ethiopia and its implications for the ontogeny and function of Australopithecus afarensis. Sci Adv. 4(7), eaar7723.

Video

*Graduate student intern project (based off of the anatomy of the Dikika foot)

Media Mentions

CNN | 3.3 million-year-old fossil shows that ancient toddlers climbed trees. July 4th, 2018 [online article]

National Geographic | Foot of ‘World’s Oldest Child’ Shows How Our Ancestors Moved. July 4th, 2018 [online article]

NBC | Baby Feet: Toddler bones show pre-human kids scampered up trees. July 4th 2018 [online article]

IFLScience | Remains of Ancient Child’s Foot Indicate Early Humans Walked Like Us, Climbed Like Apes. July 4th, 2018 [online article]

Live Science | Ancient Human Ancestors Had to Deal with Climbing Toddlers. July 4th, 2018 [online article]

Gizmodo | A Toddler Who Lived 3 Million Years Ago Could Walk Upright and Capably Climb Trees. July 4th, 2018 [online article]

Science Daily | Our human ancestors walked on two feet but their children still had a backup plan. July 4th, 2018 [online article]

ScienceNews | But a juvenile Australopithecus afarensis‘ foot still had some apelike features. July 4th, 2018 [online article]

UChicago News | Ancient fossil shows toddlers could climb trees and walk upright. July 5th, 2018 [online article]

Spiegel Online (Germany) | The evolution of modern humans began in the trees (title translated from German). July 5th, 2018 [online article]

CBC Radio | Toddler’s fossil foot opens window into human evolution. July 6, 2018 [online article]

The Leakey Foundation | Foot of Dikika Child Shows How Our Ancestors Moved. July 9th, 2018 [online article]

Darwin and Dragons Blog | Climbing Foot of Juvenile Australopithecus (translated from Spanish). July 6th, 2018 [online article]