3-million-year-old skeleton reveals the story of ancient toddlers’ lifestyles

Mindy Sparks
July 8, 2018

The full study, titled "A almost complete foot from Dikika, Ethiopia and its implications for the ontogeny and function of Australopithecus afarensis", is available to read online.

According to the lead author of the paper, Jeremy DeSilva from Dartmouth College, the features of Selam's foot seem to suggest that while being fully adapted to standing and walking on two feet, this infant A. afarensis could climb the trees easily.

Zeresenay Alemseged, paleontologist and professor of organismal biology and anatomy and the University of Chicago and senior author of the study added that "the morphology that you see in adults is the result of both their evolution through time and how they changed as they grew", which is why studying younger individuals is important.

Scientists have reanalyzed fossils of a three-million-year-old toddler of an early hominid species called Australopithecus afarensis.

However, juvenile specimens of most human hominin ancestors are scarce, and thus, it has been hard to trace how important traits are selected in animals, over time. "If you were living in Africa 3 million years ago without fire, without structures, and without any means of defense, you'd better be able to get up in a tree when the sun goes down". The professor found a skull, nearly a complete vertebral column with ribs, shoulder bones, part of her arms and legs and the foot. This attribute could have allowed them to cling to their mothers, climb trees and outsmart predators. But Selam actually died more than 100,000 years before Lucy was even alive.

"Every fossil gives us some bit of our past, [but] when you have a child skeleton, you can ask questions about growth and development-and what the life of a kid was like three million years ago", DeSilva told National Geographic.

Selam's foot was later discovered in 2002 and is about 2 inches (5.5 centimeters) long - that's a little shorter than a sticky note. They found the big toe was more capable of moving side-to-side than skeletons of similar adult feet, meaning it would be better at climbing through branches and latching onto its mother.

Over 3 million years ago, our ancient ancestors and their toddlers were standing on two feet and walking upright, it has been revealed.

"Walking on two legs is a hallmark of being human, but walking poorly in a landscape full of predators is a recipe for extinction", DeSilva said.

Their findings suggest that afarensis had human and ape-like traits based on their selective advantage, which also shows the "mosaic nature" behind the evolution of walking upright and skeletal evolution, Alemseged said.

A 2012 study of Selam's shoulder blade also showed the species would be effective when it comes to climbing.

Scientists started to study one of Selam's foot to find out more about how our ancestors walked.

Other reports by Iphone Fresh

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