Lucy, First Human Ancestor, May Not Have Been Lone Species, Research Shows

Around 3.2 million years ago, in what is now present-day Ethiopia, a tiny human made it to the fossil record. Despite much research there is uncertainty over what could have led to their death. Whatever the reason may have been, enough of the carcass was protected by sediments. This led to the bones being fossilized. Those remains, now known to the world as 'Lucy', were discovered fifty years ago, becoming one of the most significant fossil discoveries of all time.

In an interesting and intriguing recent finding, research shows that Lucy's species - Australopithecus Afarensis, was not the only early human species roaming the Earth at the time. Australopithecus Afarensis inhabited East Africa for about a million years, and paleoanthropologists have discovered many fossils of this species from north central Ethiopia to northern Tanzania, which is 1,460 miles (2,350 kilometres) away.

For decades following Lucy's discovery, paleoanthropologists believed that Australopithecus Afarensis was the sole hominid to inhabit this area throughout the middle Pliocene era (3 million to 4 million years ago). However, the image of human diversity drastically changed in 1995 when a fragmented jawbone was found in the Bahr el Ghazal region of Chad.

Believed to be 3.5 million years old, this fossil is of a species named Australopithecus Bahrelghazali. It served as evidence that other hominins lived around Lucy's time, Live Science quoted a study published in the journal PNAS in 2016.

Given that these Australopithecines were almost 1,500 miles (more than 2,400 kilometres) apart, it is possible that Lucy's type did not come into contact with them. However, Haile-Selassie and colleagues discovered Australopithecus Afarensis fossils at the Woranso-Mille site, which is only 30 miles (48 km) north of the site in Ethiopia, where Lucy was discovered. They also discovered additional, anatomically different fossils from the same time period.

The bones belonged to Australopithecus Deyiremeda, a new species of Australopithecine that was thought to have existed between 3.5 and 3.3 million years ago. Although paleoanthropologists are still divided on whether Australopithecus Deyiremeda is a distinct species from Lucy, the fact that its teeth differed significantly from Lucy's suggests that their diets were different.

As the collection of fossils from different hominin species expands, an important question arises whether these species ever interacted or even mated with each other. Australopithecus Farensis was as social as other primates, evidenced by the preserved footprint path of three Australopithecines strolling together at the Laetoli site in Tanzania. But, there is little to no proof that Australopithecines ever interbred.

Even with the enormous amount of Australopithecus Afarensis fossils found in the last 50 years, paleoanthropologists still have a lot of work ahead of them to really understand Lucy's world.