Hominids: The Beginning of Humans and Human Culture
When we look for the origins of human culture, we often point to the first civilizations: Mesopotamia, Egypt, China. At times, we remember to go further back, to cave paintings and competition with Neanderthals. Yet even as far back as the paintings at Lascaux, we have not actually reached the origins of human culture. To find the earliest signs of culture, we must continue traveling back in time to our most distant ancestors: the hominids.
Hominids began to appear around 7 million years ago, when the fossils we've found so far show the minutest changes from our primate relatives (the chimps) to traits more like modern humans. These ancestors include members of the Ardipithecus genus, who took the first upright steps: Sahelanthropus tchadensis, whose teeth are hominid-like; Orrorin tugenesis, who at 6 million years old shows the earliest adaptations of bipedalism (but the skeleton is incomplete); Ardipithecus ramidus, who at 4.4 to 5.8-million years old shows ape-like dentition (teeth) with evidence of bipedalism in over 17 fossils; and Ardipithecus kadabba, who also walked upright and was much like a modern chimp. Unfortunately, all of these candidates for "earliest human" are incomplete. This leaves a period of about 3 million years in the fossil record in which we believe the changes between primate and human might have began.
Yet, we know that around 4.5 million years ago, our last common ancestor with chimps lived. In 1966, Vincent Sarich and Allan Wilson did a biochemical comparison of the blood proteins between humans and primates. Their work established that our ascent from primate to man began around 12 million years ago (when we diverged from gibbons), continued at 10 million years ago (diverging from orangutans), and had reached the "primate-human" divide (from gorillas and chimps) by 4.5 million years ago. Thus, the common ancestor of chimps and humans is believed, in molecular biology, to have lived between 4 and 6 million years ago. The fossil record corroborates the biology.
The first definite hominids, from the genus Australopithecus (called Australopithecines) and the Paranthropus genus lived about 3.5 to 4 million years ago. These ancestors showed the first adaptations to distinguish humans from primates: small canines, flat and thickly enameled molars, a parabolic dental arch, and - most significantly - bipedal locomotion (walking on two legs). It also includes several ancestors of modern humans, who are divided into two groups: gracile hominids and robust hominids.
First, there are the robust hominids, who are found primarily in east and south Africa. These include the finds in Olduvai Gorge by George and Mary Leakey in the 1950s and 1960s. Most are dated to between 2.7 and 1 million years ago. Compared to the primates and gracile hominids, robust hominids have thicker jaws with larger molars and smaller incisors, more massive muscle attachments for chewing, and a much larger cranial capacity of about 490 to 530 cc. They include A. aethipicus (2.3 to 2.7 million years old), A. robustus, and A. boisei (2.3 to 3.1 million years old). It also includes the Paranthropus genus: P. aethiopicus, 2.5 million years old with a strongly protruding face, large teeth, and a powerful jaw; P. boisei, 2.3 to 1.2 million years old, who had cheek teeth four times the size of a modern human's; and P. robustus, 1.8 to 1.2 million years old. These robust hominids became extinct about 1 million years ago, leaving the gracile hominids to continue the evolutionary path to modern humanity.
Gracile hominids exhibit a smaller dentition and lighter facial musculature (i.e., their faces are more fine-featured) than the robust. The earliest is Australopithecus anamensis, dated from 4.2 to 3.9 million years ago in Kenya and Ethiopia. It has a combination of traits between primates and humans, and its human-like ankle joint orientation is indicative of regular bipedal walking, though it also had long forearms and wrist bones made for climbing trees. Fossils suggest A. anamensis was about the size of a female chimp and likely ate hard, abrasive foods, like plants, fruits, and nuts native to their forest and woodland climate.
Then, at about 3.8 million years ago, came Australopithecus afarensis, whose remains are quite numerous in the fossil record: over 300 individuals have been found so far! This includes the famous 2.9-million-year-old "Lucy," an adult female skeleton found in Hadar, Ethiopia, as well as the Laetoli footprints: an 88-foot line of hardened human-like footprints, preserved in volcanic ash, that include the impressions of 70 footprints from 2 or 3 individuals. A. afarensis had many new features: they were able to move their jaws from side to side, allowing them to easily chew seeds and nuts; a slightly bigger brain than A. anamensis (about 375 to 550 cc); curved finger and toe bones (which meant they were heavily muscled); and they were sexually dimorphic (meaning females and males had different average weights and heights). They grew to between 3 and 5 feet tall and weighed between 64 and 92 pounds. They were the longest-lived of early human species, living nearly 900,000 years in Eastern Africa.
Then, at about 3 million years ago, came Australopithecus africanus (the "southern ape of Africa"), who had a larger brain and smaller teeth. An adult weighed between 66 and 90 pounds and had a height between 3 ft 9 in and 4 ft 6 in Included among the skeletons found is that of a 3.5-year-old child (called "Taung Child"), thought to have been killed by an eagle due to puncture marks found in the eye sockets resembling a modern eagle's talons, and hundreds of discoveries at Sterkfontein Cave (in Johannesburg) and Makapansgat.
The What and the Why
It was these first hominids, the Australopithecines, that exhibited the first signs of human culture. But what is culture? What defines this drastic step in human evolution? How do we separate out culture from the activities of other species?
First, you must understand that culture is a set of interrelated processes. It is not one single action or aspect: it is the sum of the parts that allows us to call it "culture." These parts are specific patterns of behavior, such as toolmaking. Any creature could fashion a type of weapon: in fact, chimps have been seen making weapons for hunting. Rather, it is the repetition and refinement of the process that distinguishes it as an aspect of culture. Thus, we can consider the presence of patterned stone tools - that were made using the same process and are found in mass quantities - as a sign of human culture.
Second, we must understand how culture is different from animal behavior. There are three parts to this:
- Culture is learned and shared -- it is something that an individual acquires during their lifetime as they mature and interact with others;
- Culture is generally adaptive -- these learned and shared behaviors develop and spread throughout a group of individuals because those behaviors help the group to survive. It is our ability to learn and share behavior, as well as adapt the behavior to different climates and conditions, that distinguishes us.
- Culture is always changing -- these behaviors are constantly being refined to work out contradictions between old ways that are no longer efficient and new resources, conditions, and methods that make the behavior more efficient and effective for survival.
Now that we know what culture is, and how it differs from animal behavior, we must ask a final question: why did culture develop?
Truth is, we don't quite know. We may never know all the reasons: history is a mystery to the end. Yet there are some clues, primarily found in the fossil record. First, we know that by the time culture appeared, the human brain had begun surpassing the cranial capacity of apes. This expansion began around 2.3 million years ago. Though we don't know the exact reason, brain size increased drastically after 2 million years ago, doubling in relative size and tripling in absolute size by the time we get to modern humans. This increase is linked to the emergence of stone tool-making at about 2.5-million years ago because increased cranial capacity results in finer motor and conceptual skills as well as a longer life span.
Second, there was a reduction in the face, teeth, and jaw size when Australopithecus evolved into the Homo genus. Australopithecus had large cheek teeth relative to their estimated body weight, thick jawbones, and relatively large faces that projected forward below the eyes. In contrast, Homo's features were reduced and finer, allowing them to eat foods that were easier to chew, likely leading to a change in diet and the development of cooking.
Third, we were becoming less hairy. And in a world without factories or shopping malls, this was a huge deal. Without hair to cover the body, early humans needed to find ways to stay warm. This meant killing animals not only for food, but now for clothing as well. And in order to make clothing, you need tools to kill, skin, and process the hides.
Thus, human culture developed. But what did this culture include?
Aspects of Early Human Culture
The earliest signs of culture were tools. In response to a different diet and the need for clothing, early humans began to make tools to aid in cutting meat and hides. The earliest identifiable stone tools date to about 2.5 million years ago in East Africa; these include around 3,000 tools found in Gona, Ethiopia, that were made by percussion flaking (striking a stone with another stone). By 2 million years ago, evidence from animal bones shows that humans were using these tools to cut up carcasses from meat and hides. (Note that they were only cutting meat - early hominids were likely opportunists, scavenging from carcasses left by other predators, rather than hunters.)
In 1911, the first definitive style of toolmaking was identified in Olduvai Gorge. The tool assemblages there - now known as "Olduvan Tools" - date to about 1.6 million years ago and include core tools, sharp-edged flakes, and "choppers" (cores that have been partially flaked with side, likely used to chop things). The Olduvan Tools were used for slitting the hides of animals, dismembering animals, whittling wood into sharp points, hacking off branches, and cutting and chopping through tough animal joints. However, none of these tools were likely used as weapons.
The British Museum included Olduvan tools in its History of the World in 100 Objects series. They included an Olduvan chopper dated to 1.8 million years ago. The chopper is very heavy and fits in the palm of your hand, likely being used as a sharp knife to cut meat, roots, and bark. The chopper is also unique in its design. Unlike tools made by chimps and other species, the Olduvan chopper is more complex than is necessary; a simple chopper, made with 2 chips, would have done the job sufficiently. Yet the Olduvan chopper is made with 8 chips, thus a more elaborate tool that makes the process more efficient. Such intent in design is likely a sign of complex thinking: of an intention not just to make a tool for the moment, but to make a tool that could be used repeatedly and efficiently.
The Olduvan tools also included a hand axe: the first tool to be carried by our ancestors with them during their migrations around - and out of - Africa. The hand axe is extremely tricky to make, yet its design did not change during its nearly 1 million years of use. The one on display at the British Museum dates to 1.2 million years ago, made in a teardrop shape out of volcanic rock with a sharp, long edge and a point. It was a multi-use tool: a drill, axe, knife, and scraper all in one tool - leading it to be called the "swiss army knife" of the hominids.
Due to its complexity, the hand axe is evidence that our hominid ancestors were already exhibiting many traits that make us human: manual dexterity, complex planning, imagination, and - perhaps - speech. Modern brain scans of individuals making Olduvan tools (as our ancestors would have) show that the same areas of the brain used to make the hand axe overlap with the areas needed for speech, leading us to believe that our hominid ancestors were capable of exchanging ideas and planning: the founding blocks of human society. This is backed up by the high concentrations of debris from their toolmaking may be a sign of campsites. The large numbers of tools and bones found in any given site are indicative that such sites were used by groups over long periods of time, perhaps even recurring periods of time. This suggests that early hominids shared hunting and food gathering activities, which in turn suggests that hominids were developing relationships with one another (as family groups). This is supported by evidence from modern chimps who share food with closely related individuals.
The evidence reveals some key aspects of early hominid culture. First, hominids were nomadic, moving around on a regular basis from dry season to wet season sites. Second, hominids ate a wide range of animals: bones include those of antelopes, wild pigs, elephants, and giraffes. This further supports early hominids being opportunists: scavenging rather than hunting. Finally, many of the sites where concentrations of bones and tools have been found may not have been "homes;" instead, they were likely sites specifically for food processing. This is suggested by the presence of carcasses that were not fully butchered, the presence of other predators, and natural processes that - over time - can create circles of debris that look more like structures than piles. Early hominids may have left their special processing tools at specific sites so as to avoid carrying them around during migrations. Unfortunately, we'll never know for sure, but this is the best picture of early hominids that we have.
This means that, by 1.2 million years ago, we were not only making tools. We were able to find better food, skin animals for clothing and shelter, communicate with one another (likely at the level of a 7-year-old child), and - most importantly - imagine. We were living in groups, exchanging ideas and planning better ways to gather the resources for our survival. Such advances meant profound changes were in store for hominids and their descendants. Our new abilities would lead to the greatest diaspora in our history: our journey out of Africa. Within 700,000 years, our ancestors would reach Britain and Korea, still carrying and using Olduvan hand axes.
Making Oldowan Tools
Thus, human culture didn't start with the first civilizations. It was far older than that, older than Lascaux, older than most have ever imagined. Human culture has been developing since our very separation from apes on the family tree. Ever since our ancestors began to make the first tools, we have been participating in behaviors that distinguish us from other animals. We have learned and shared processes - evolving these behaviors as much as we have evolved - and have continually sought to enhance our efficiency and effectiveness in order to survive. Additionally, we have gained the ability to imagine: to plan ahead as well as consider new possibilities.
Our ancestors never stopped learning. Australopithecines had a long way to go to get to where modern humans are now, but they took the first steps: toolmaking. It would be up to the next in line, the earliest of the Homo genus, to refine tools that would eventually lead to that most pivotal moment in human history: the use of fire. But that's another hub.
Next in this series: Homo Rising