The assimilation model is where Smith and Trinkus argue that modern humans expanded out of Africa. Interbreeding between premodern humans and modern humans was a small 1 – 4% and localized to regional populations. This model is supported by Cann’s research which concluded that we all share mitochondria. This mitochondria links us to one common ancestor known as Mitochondrial Eve. Mitochondrial Eve, is the only mutation variation with a molecular clock, and with a steady rate in MTDNA. Mitochondrial Eve traces back 200,000 years ago. Modern humans also have 1 – 4% of Neandertal DNA. This supports the assimilation model (Lecture Outline: Premodern and Modern Human).
Prior to the rise of premodern and modern humans there was Homo sapiens neanderthalensis. Homo sapiens neanderthalensis was the precursor that paved way for premodern and modern humans. Forces of evolution constantly challenged them to survive or die. They had at hand help that they were born with. Their extraordinary characteristics reflected the cold environment they lived in. In turn their chances of survival were higher but it was not at an easy cost. Their characteristics included a nasal aperture that was wide, which was primitive, and tall. Their face projected, they had huge noses, which prevented nose bleeds from occurring because of the cold climate. Having a huge nose allowed increase air flow in the external environment and brain. The width in their nasal aperture allowed air to come in slower, which provided warmth, and humidity. They still had a little occipital bun. Their skull was long and there was a low movement towards a globular head. Their front teeth were large. Their body was wide and stocky which kept them warm. Their limbs were short. Their wide and stocky body and short limbs reflected Bergmann’s and Allen’s rules. Professor Nicole Quinn says, “They reflected how they were born out of the ice age and survived the ice age.” (Lecture Outline: Premodern and Modern Human).
Aside from the cold climate that challenged Homo sapiens neanderthalensis’ survival, limited resources were a challenge they had to face, and they worked with whatever they got. In Europe, Krapina’s 130ybp excavation uncovered large teeth, and back teeth were small. Their teeth were the biggest front teeth in human Hominin evolution. They used their teeth to scrape meat off bone, since their teeth were well adapted to this it prevented chipping. Cut marks on animal and human bones were found. They put animal and human bones together. It is a slight indicator that there might have still not been a reflection of mourning. Cannibalism was an adaptation necessary for survival. Cannibalism consumption was a high make-up for lack of animal meat which their brains demanded. Krapina gave the world the first appearance of “classic” Neandertal traits: their eyes are rounded; there is a wide space between them like most modern humans, mid-face protrusion gave larger teeth and nose, and wide nasal aperture was for warming air. (Lecture Outline: Premodern and Modern Human).
In El Sidron, Spain 50k-40kya, 12 individuals were uncovered that gave a residence, and mating patterns similar to today. All the men were related to one another. Females went off to the male’s group; because when united due to blood relations it led for males to be better hunters, and warriors. This allowed the men to strategize, attack, and plan more cooperatively and tactically. In turn survival was much higher. There was still cut marks on humans bones, but this time without animal remains, this was either an adaptation or cultural practice. They would smash the bone marrow as a source of food. In La Chapelle-aux-Saints, France – 60kya years ago typical Neandertal traits were emerging. One individual uncovered had a hunchback due to arthritis in the spine. This misrepresented this Neadertral as ape-like. This claim, “disregarded that Neandertals were evolutionary successful and not barbarians” (Lecture Outline: Premodern and Modern Human).
The true climax began in Tabun, Israel – 170kya – 110kya when a female with a very large brain was discovered. In Kebrara, Israel a small hyoid bone for speech was found. Gene flow began; all changes at this point were similar to modern humans. In Amud, Israel – 55k – 40kya an adult male with a very large brain was found. His brain was at 1740cc, which was outside the average of modern human; because modern humans range at 1450cc. Genetic drift began when both Kebara and Amud Neandertals were able to share some modern traits. They were first to come in contact with modern human interbreeding. Interbreeding was possible do to them sharing no occipital bun (modern human like from back of head) and teeth size was decreased. These archaeological findings support the assimilation model. Interbreeding was indeed localized to regional populations (Lecture Outline: Premodern and Modern Human).
Indications of feelings began bursting throughout archeological evidence. In Shanidar, Northern Iraq – 45kya in Shanidar 1 an older male of 35 – 45 years was discovered. This was quite old for the period of time he lived in. Morphology of this man was typically Neandertal and he had lived a rough life. He had fractured his left side of the head but it healed. There is an indication that he was possibly blind, he had advanced arthritis, a withered right arm and shoulder, and he also had a fractured right foot that healed. He lived this long do to having help from immediate family he was traveling with. This is some evidence of compassion amongst Neandertals surfacing (Lecture Outline: Premodern and Modern Human).
Bicultural evolution started drizzling itself in the Middle Paleolithic era. The culture of Neandertals boomed. Mousterian tool industry rose and was frequent 300 – 30 kya ago. The specialized tools they were using reflected the heavy reliance on animal protein and meat, skinning, and hunting. Tool usage was technologically complex and integrated in their culture. The tool they used was levallois for scraping skin and meat. Their diet was based on hunting. They ate meat and at times some plants. They had good hand-eye coordination, and had rodeo injuries when hunting, which they healed from. They ate marine food and exploited shell fish. There is fishing evidence, but marine food is not as high in protein, and nutrition decreases when consumed. Neandertal language was a symbol. They had a FOXP2 mutation that is also found in contemporary human beings. They developed a lateralized brain because of tool usage with their right arm. Contemporary humans also have lateralized brains. Feelings became more apparent through Neandertal burials. They made deliberate burials and buried their dead. They began to question their mortality and most of their dead were buried in flex position. This highlighted that the position was intentional. Symbols were on the rise other than language in their culture. Art was being made in form of red ocher and shell beads. Holes were made in marine shells, dyed with ocher, and turned into necklaces. This was made for “art for art’s sake” (Lecture Outline: Premodern and Modern Human).
Along came Early Modern Homo sapiens, from Africa- 200k – 195k. The date of this archeological finding supports the assimilation model with Cann’s research of Mitochondrial Eve. In Omo Kibish, Ehtiopia 195k ya the earliest modern human was found. They were more delicate, taller, and started making their way into being “the ballerinas” of Homo history. Omo 1 was modern in all respects while Omo 2 was more robust and less modern. In Herto, Ethipoia 160k – 154k ya a “near modern” H. sapiens defined as a subspecies H. sapien idaltu was found. This marked a regional variation of a modern human. Their primitive traits consisted of relatively long face, while their derived traits were a more globular cranium that was rounded, and tall. A vertical forehead, their brow ridges were a bit smaller, while their cranial capacity was at 1450cc (Lecture Outline: Premodern and Modern Human).
In Israel – 90kya many male skulls were found. There was evidence that modern humans were here before Neandertal. This was an indicator that early archaic groups lived side by side. As the assimilation model states, “interbreeding between premodern humans and modern humans was a small 1 – 4% and localized to regional populations”, and these findings continue to support the model’s theory (Lecture Outline: Premodern and Modern Human).
In Zhiren Cave, China 100kya there was a small indication of modern human practices occurring. The primitive trait found was their mandible that was thick. They had few molars. The derived traits were a modern chin. A chin highlights and emphasizes modern humans. In Europe, 35k – 15kya in an Oase Cave in Romania – 35kya, Oase 2 skull was found with derived traits: significantly smaller browridges and they were gracile. Here some Neandertals were close enough to interbreed because of the FOXP2 mutation, the hyboid bone, and a lateralized brain. All these were moments in time that were pivotal to occur in order for Modern man to surface. Cann’s research helps secure and support the assimilation’s model’s theory, so does the archaeological evidence (Lecture Outline: Premodern and Modern Human).
Bibliography
Quinn, Nicole. "Premodern and Modern Human." Lecture.
© 2015 Raquel Reyes-Lopez