The air is hot and dry, the ground dusty. All around young graduate students are cautiously sweeping the dirt away in hopes of finding hominin fossil fragments and quenching their thirst for fame and knowledge. They are paleoanthropologists. Individuals who strive to better understand and catalog human ancestry. Defined as “the study of ancient humans,” paleoanthropology is a branch of anthropology that strives to reconstruct all aspects of human evolution. A multidisciplinary field, it combines disciplines like archaeology, anthropology, paleontology, and geology to observe the anatomy, behavior, and ecology across the human lineage with a primary focus on early human evolution known as the hominin lineage. By better understanding the hominin lineage, paleoanthropologists attempt to discover how early hominins lived and “how” and “why” certain species evolved in anatomically modern humans, or died out.
How Do Paleoanthropologists Answer These Questions?
Paleoanthropologists use early archaeological, hominin, and paleoenvironment evidence, to begin reconstructing our ancient past. Evidence often includes fossilized bone from both hominins and other animals, lithics (stone tools), plant and animal matter, footprints, evidence of hearths, butchery marks on animal bones and art. Using these materials, researchers can then establish a hypothesis and narrative to explain the physical and behavioral makeup of early hominins and how it has altered across a spatial and temporal timescale.
How To Create A Paleoanthropologist Narrative
Let go back to our graduate students digging in the hot sun. Say for example one of them discovers an Acheulean biface tool along with an extremely “primitive” fossilized hominin hand like Australopithecus Sediba.
Assuming that this graduate student has adequate knowledge of hominin functional morphology, they might note that the dexterity required to create an Acheulean biface surpasses the dexterity found in the fossilized hand. As a result, the graduate student is faced with 3 potential hypotheses:
- the tool was not created by the hand of the “primitive” hominin found with the tool and was created by a different hominin species living at the same time.
- The deposit in which the tool and the hominin were found was mixed in with another deposit layer.
- The tool was indeed created by the hand of that hominin and all our previous understanding of hand morphology is flawed.
Where To Find Hominin Remains?
To locate fossils, paleoanthropologists typically look for areas that would have been ideal environments for hominin hundreds of thousands of years ago. This can be anything from sediments of the right time period being exposed by natural erosion to educated guesses based on the locations of previously discovered fossil specimens. One of the most common places to locate early hominin remains is in Africa. Within Africa, fossil remains are split into two groups depending on their location: East and South.
East African Fossil Specimens
Located in East Africa, East African fossil specimens are typically located throughout rift valleys. Rift valleys are caused when portions of the earth’s crusts have been pulled apart due to the movement of tectonic plates. This movement of plates causes deep valley and trench-like formations surrounded by large mountain ranges. Fossils, if found, will usually be exposed along the sides and floors of the rift valleys due to rivers and streams eroding deep into the sediment layers.
South African Fossil Specimens
Located in the southern part of Africa, South Africa fossil specimens are typically found in caves. This is mainly due to South Africa having large limestone deposits everywhere. Since limestone is extremely porous, as rainwater runs through a limestone crack it erodes surrounding limestone, eventually expanding into caves and tunnels. While hominin fossils are located within caves there is weak evidence which suggests that early hominins used caves as habitation sites. Paleoanthropologists actually believe that the majority of hominin fossils found in caves were brought in by predators like leopards or hyenas, bone collecting animals like the porcupine, or were washed in by rain from any cave opening. Hominin fossils in South Africa are typically found when miners blast the caves in order to attain the limestone or other mineral resources. The famed Taung Child, for example, was discovered at the Buxton limestone quarry in the Northwestern Province of South Africa following a mining blast.
Why Is Paloanthropology Important?
Paleoanthropologists constantly strive to discover fossils and artifacts since they are a physical evidentiary timestamp of a particular event. Unfortunately, fossils are quite rare and often it is up to paleoanthropologists to hypothesize what occurred over the last 4 million years. By probing into the past, researchers, like our graduate students, can begin to ask some of the broader questions surrounding our evolutionary history, and perhaps, glean important information into who we are.