Chan, Keith. Assimilation Model. n.d. LibreTexts. https://socialsci.libretexts.org/Courses/Fresno_City_College/ANTH-1%3A_Explorations_2nd_Edition/12%3A_Modern_Homo_sapiens/12.03%3A_The_Big_Picture_-_The_Assimilation_Hypothesis.
Embedded Files
Assimilation Model
Assimilation Model
The assimilation model is a type of dispersion model that represents hominid movement out of Africa.
This model mainly represents the movement of modern hominids, with the implication of interbreeding between H. sapiens and other archaic human species.
Additionally, it also expresses the fact that archaic and modern humans coexisted.
The process of movement from the assimilation model started with the exit of East Africa and the entrance into West Africa and Eurasia. While traveling into these "new" areas, interbreeding between archaic and modern humans occurred (Smith et al., 2016).
Why is the Assimilation Model Important?
Why is the Assimilation Model Important?
Prior knowledge of early Homo sapiens origins believed that populations replaced each other. This was proven wrong because H. sapiens and Neanderthal populations "blended".
Timing and Occurrence of Interbreeding
Timing and Occurrence of Interbreeding
In comparison to the entire hominid evolution time scale, the appearance of "proof" of interbreeding between archaic and modern hominins. Specifically, the interbreeding of Neanderthals and Homo sapiens would have most likely been between 47,000-65,000 years ago (Sankararaman 2012). It is believed that "interbreeding may have occurred when modern humans carrying Upper Paleolithic technologies encountered Neanderthals as they expanded out of Africa (Sankararaman 2012).
Fossil Evidence of the Assimilation Model
Fossil Evidence of the Assimilation Model
Evidence that has been found for the assimilation model represents features that are a mix of modern and archaic human traits. This blend of traits is what supports/represents the assimilation model.
The Skhul V fossil was found at the Es-Skhul site in Haifa, Israel. Additionally, another mosaic fossil is Lagar Velho-1, which was found at the Lagar Velho site in Portugal.
Skhūl V. Smithsonian Museum of Natural History. Smithsonian. Accessed April 14, 2025. https://humanorigins.si.edu/evidence/human-fossils/fossils/skh%C5%ABl-v.
Skhul V fossil
Skhul V fossil
Archaic Traits
More pronounced brow ridge
prognathic lower face
Modern Traits
High, vertical forehead
Large cranial capacity (1518 cc)
Rounded occipital
No occipital bun
Chin
(ORSA Editors)
Liberty-Shalev, R. Skhul Cave. December 1, 2010. UNESCO - World Heritage Convention. https://whc.unesco.org/en/documents/117471.
Es-Skhul Site
Es-Skhul Site
This site is located at Skhul Cave, Mount Carmel, Israel. The Skhul V fossil was discovered in 1932 by Ted McCown and dated to 100 to 130 kya (Issac 2025).
Lagar Velho Child. January 7, 2010. University of Bristol. https://www.bristol.ac.uk/news/2010/6777.html.
Lagar Velho-1
Lagar Velho-1
Archaic Traits
Stocky Neanderthal body
Modern Traits
Prominent chin
Small front teeth
(Duarte et al., 1999)
Zilhao, Joao. Lagar Velho before excavation. Don’s Maps. Accessed April 8, 2025. https://www.donsmaps.com/lagar.html#:~:text=Morphological%20mosaic%20found%20on%20this,and%20a%20backward%2Dsloping%20mandible.
Lagar Velho Site
Lagar Velho Site
Located in the Lapedo Valley, Central Portugal. The site was discovered on November 28th, 1998 by João Maurício and Pedro Souto (Encyclopedia Britannica Editors 2015).
Archaeological Evidence of the Assimilation Model
Archaeological Evidence of the Assimilation Model
Specific archaeological evidence of the assimilation model would be at the Grotte Mandrin Cave in Mediterranean France. Excavations at this site revealed successive replacement occupation phases at this particular site. This means that occupants of the site rotated between Neanderthals and modern Homo sapiens. This site possesses stratigraphic layers that range from the end of the Middle Paleolithic to the start of the Upper Paleolithic. After excavating this site, it yielded an estimated number of around 60,000 lithic objects, as well as 70,000 faunal remains (horse, bison, and deer remains).
After further examination of the site, teeth were found throughout the layers. They were able to determine which teeth correlated with their respective species. Based on what layer the teeth were found in, researchers were able to relate that species with the tools that were found in that same stratigraphic layer.
The specific aspect of the research and excavation on this site, which support the assimilation model, was the fact that there were modern Homo sapiens teeth in layers with a certain type of tool industry called "Neronian industry". The significance of modern Homo sapiens being found at this site, specifically the stratigraphic layer they were found on, shows that modern Homo sapiens inhabiting Europe occurred between 56,800-51,700 years ago (which was 10,000 years earlier than initially thought).
Mousterian (Middle Paleolithic) tools are mainly associated with Neanderthals, and even some early Homo sapiens adapted this method of toolmaking as well. Additionally, it is assumed that since Homo sapiens and Neanderthals lived in such proximity, they learned from each other. Certain pieces of evidence provided show that Neanderthals that inhabited the site or near where the Homo sapiens inhabited developed altered tool-making techniques. This change is reflected in the rise of the transitional Châtelperronian industry (which blends both Mousterian and methods from Upper Paleolithic methods).
(Slimak et al., 2022)
Mousterian Tools
Mousterian Tools
The Editors of Encyclopaedia Britannica. "Mousterian industry." Encyclopedia Britannica, October 17, 2016. https://www.britannica.com/topic/Mousterian-industry.
Neronian Tools
Neronian Tools
Djakovic, Igor. Stone Tools in Shifting Sands: Past, Present, and Future Perspectives on the Châtelperronian Stone Tool Industry. September 2024. ResearchGate. https://www.researchgate.net/figure/Chatelperronian-crested-blades-b-d-and-bladelet-a-from-initialisation-configuration_fig1_384218964.
Châtelperronian Tools
Châtelperronian Tools
Ashworth, James. Oldest evidence of modern humans in western Europe discovered. February 9, 2022. Natural History Museum. https://www.nhm.ac.uk/discover/news/2022/february/oldest-evidence-modern-humans-western-europe-discovered.html.
What Helped Solidify the Assimilation Model (genetically)?
What Helped Solidify the Assimilation Model (genetically)?
The assimilation model wasn't as popular as the other dispersion models. However, after the first Neanderthal draft genome was published in 2010, there was direct evidence of "low levels of archaic human gene flow into modern Eurasian populations..." (Smith et al., 2016)
References
References
Bibliography
Duarte, Cidália, João Maurício, Paul B. Pettitt, Pedro Souto, Erik Trinkaus, Hans van der Plicht, and João Zilhão. “The Early Upper Paleolithic Human Skeleton from the Abrigo Do Lagar Velho (Portugal) and Modern Human Emergence in Iberia.” Proceedings of the National Academy of Sciences 96, no. 13 (June 22, 1999): 7604–9. https://doi.org/10.1073/pnas.96.13.7604.
Fu, Qiaomei, Mateja Hajdinjak, Oana Teodora Moldovan, Silviu Constantin, Swapan Mallick, Pontus Skoglund, Nick Patterson, et al. “An Early Modern Human from Romania with a Recent Neanderthal Ancestor.” Nature 524, no. 7564 (June 22, 2015): 216–19. https://doi.org/10.1038/nature14558.
Issac, Carolyn. “Out of Africa.” Lecture, April 8, 2025.
Ko, Kwang Hyun. “Hominin Interbreeding and the Evolution of Human Variation.” Journal of Biological Research-Thessaloniki 23, no. 1 (July 16, 2016). https://doi.org/10.1186/s40709-016-0054-7.
McHenry, Henry. “Skhūl.” Encyclopedia Britannica, December 5, 2023. https://www.britannica.com/place/Skhul.
Sankararaman, Sriram, Nick Patterson, Heng Li, Svante Pääbo, and David Reich. “The Date of Interbreeding between Neandertals and Modern Humans.” PLoS Genetics 8, no. 10 (October 4, 2012). https://doi.org/10.1371/journal.pgen.1002947.
“Skhul v Details.” Welcome to the Open Research Scan Archive! Accessed March 25, 2025. https://orsa.iu.edu/SkhulV_details.html.
“Skhūl v | The Smithsonian Institution’s Human Origins Program.” Smithsonian National Museum of Natural History. Accessed March 25, 2025. https://humanorigins.si.edu/evidence/human-fossils/fossils/skhūl-v.
Slimak, Ludovic, Clément Zanolli, Tom Higham, Marine Frouin, Jean-Luc Schwenninger, Lee J. Arnold, Martina Demuro, et al. “Modern Human Incursion into Neanderthal Territories 54,000 Years Ago at Mandrin, France.” Science Advances 8, no. 6 (February 11, 2022). https://doi.org/10.1126/sciadv.abj9496.
Smith, Fred H. “Assimilation Model of Modern Human Origins.” The International Encyclopedia of Biological Anthropology, October 4, 2018, 1–4. https://doi.org/10.1002/9781118584538.ieba0550.
Smith, Fred H., Ivor Janković, and Ivor Karavanić. “The Assimilation Model, Modern Human Origins in Europe, and the Extinction of Neandertals.” Quaternary International 137, no. 1 (January 21, 2005): 7–19. https://doi.org/10.1016/j.quaint.2004.11.016.
Smith, Fred H., James C.M. Ahern, Ivor Janković, and Ivor Karavanić. “The Assimilation Model of Modern Human Origins in Light of Current Genetic and Genomic Knowledge.” Quaternary International 450 (August 9, 2017): 126–36. https://doi.org/10.1016/j.quaint.2016.06.008.
The Editors of Encyclopaedia Britannica. "Lagar Velho." Encyclopedia Britannica, January 11, 2015. https://www.britannica.com/place/Lagar-Velho.
Tryon, Christian, and Sarah Bailey. “Testing Models of Modern Human Origins with Archaeology and Anatomy.” Nature news, 2013. https://www.nature.com/scitable/knowledge/library/testing-models-of-modern-human-origins-with-96639156/.
Villanea, Fernando A., and Joshua G. Schraiber. “Multiple Episodes of Interbreeding between Neanderthal and Modern Humans.” Nature Ecology & Evolution 3, no. 1 (November 26, 2018): 39–44. https://doi.org/10.1038/s41559-018-0735-8.
This page was completed by Carlee Sheets.
Page updated
Report abuse