4 questions about new human relatives

The discovery of new human relatives called Homo naledi (H. naledi) in a deep cave in South Africa raises many questions around their existence.

Questions about new human relatives

What makes H. naledi species different?

Portraits of Homo naledi simulated by painter John Gurche from images of skeletons.(Photo: Mark Thiessen / National Geographic).

Previously, most anthropologists believed that brain size and the ability to use tools were associated with the reduction of teeth, better nutrition, larger body and longer legs. In this view, changes in primitive human bodies result from behavioral changes, affecting diet and brain, and H.naledi is an exception. This species has small teeth and hands suitable for making tools but also possesses small brains. In addition, H. naledi has human-like long legs and feet but the shoulders and fingers can help climb effectively.

Body shape sketched from bone fragments of H. naledi (right) placed next to other species such as H. erectus (middle) and australopithecines (left).(Photo: National Geographic).

When did the H. naledi species appear?

If H. naledi is more than two million years old, the new species will show the earliest appearance of the genus. If they appeared nearly a million years ago, it is possible to infer several different primitive groups living simultaneously in southern Africa, including the small brain H. naledi.

The researchers explored deep cavities in the Rising Star limestone cave, which houses more than 1,500 fossils of new species.(Photo: National Geographic).

Why did the H. naledi people enter the Dinaledi cavern in the Rising Star cave?

This is a very difficult question to answer. Geological research shows that the Dinaledi cavity is always hidden in the darkness, and the path that goes down is very complicated, requiring the identification of the direction between the rugged terrain. This suggests that H. naledi may have borrowed the light of the fire to guide the cave.

A skeleton of the H. naledi is placed among hundreds of other fossil samples taken from the Rising Star cave.(Photo: National Geographic).

Why are there many human bones of H. naledi in Dinaledi niches?

This question has important implications. The study showed intact bones. They can be submerged after a long time and are pushed into niches but the way we go down today. The team has not found evidence that the skeletons are the result after the H. naledi fell into the cave, were attacked or massacred by beasts. It indicates that the H. naledi may enter the cave with the intention of burying the corpse in the dark cavity.