The analysis of a complete, approximately 1.8-million-year-old hominid skull from Dmanisi, Georgia, suggests that the earliest members of the Homo genus actually belonged to the same species.
Skulls over time
Pictured: Dmanisi skulls 1-5. The final skull is the 1.8-million-year-old hominid skull from Dmanisi, Georgia. It is the best preserved example yet of a hominid species that once roamed the forests and plains of western Asia – the first members of the genus Homo, which includes modern humans, to wander out of Africa. It's characterized by a small brain case, a long face, with large teeth and massive jaw.
Over millions of years, Homo sapiens and their ancestors have changed and developed. These changes are outlined below and correspond to the numbers on the chart.
- 1. Adaptations for walking bipedally, smaller canine teeth
- 2. Enlarged cheek teeth and jaws
- 3. Massive cheek teeth and jaws, enlarged chewing muscles
- 4. Slightly larger brain, more vertical face without a snout, fingers capable of precision grip, ability to make simple stone tools for processing food, including meat
- 5. Smaller jaws and cheek teeth, long legs and arched feet well-suited for long-distance walking and running, larger brain
- 6. Sophisticated stone flakes, tools for hunting, brain size increases
- 7. Large brain, small face tucked below brain case, rounded cranial vault, small brow ridges, capacity for art, symbolic thought, full-blown language
Behind our ancestors
The above chart also shows the ancestors of Homo sapiens over time, with periods colour-coded by different groups.
Ardipithecus group: The earliest humans are our closest link to other primates. They evolved in Africa and took the first steps toward walking upright.
Australopithecus group: Species in this group of early humans walked upright on a regular basis, but they still climbed trees.
Paranthropus group: Large teeth and powerful jaws enabled this group to feed on a variety of foods.
Homo group: Like modern humans, other species in this group had large brains and used tools. Members of this group were the first to expand beyond Africa.
SOURCES: UNIVERSITY OF CALIFORNIA, BERKELEY; MARCIA PONCE DE LEON AND CHRISTOPH ZOLLIKOFER, UNIVERSITY OF ZURICH, SWITZERLAND; SMITHSONIAN INSTITUTION