Homo neanderthalensis and Homo sapiens sapiens

13-6 Homo sapiens neanderthalensis and Homo sapiens sapiens

Homo neanderthalensis and Homo sapiens appear in the fossil record approximately 300,000 years ago.  Homo neanderthalensis lived in cold climates in Europe, the Middle East, and the Steppe (Figure 13-21). Their bodies were adapted to cold climates and were thus shorter and stockier than Homo sapiens.[1] Although their brains (1200 – 1700 cc) had approximately the same volumes as Homo sapiens (1000 – 1800 cc); their skulls were flatter and longer (Figure 13-22), and they had distinct eyebrow ridges, as with other archaic humans. 

Homo sapiens evolved in Africa; however, there was periodic genetic mixing between Homo sapiens and Homo neanderthalensis both when Homo sapiens came out of Africa (60,000 years ago) and beforehand. Recently, scientists discovered that Homo neanderthalensis Y chromosome DNA indicates that there was a male Homo sapiens ancestor of all Homo neanderthalensis. [2] This Y-chromosome replacement probably entered the gene pool of Homo neanderthalensis more than 100,000 years ago, before Homo sapiens left Africa. Female mitochondrial DNA also indicates that all female Homo neanderthalensis were descended from a female Homo sapiens.[3] This insertion of Homo sapiens female mitochondrial DNA into the Homo neanderthalensis gene pool probably took place between 400,000 and 200,000 years ago.

The fact that Homo sapiens and Homo neanderthalensis interbred, even to the point that all Homo neanderthalensis Y-chromosome and mitochondrial DNA was closer to Homo sapiens than Denisovan DNA means that they should be considered as one species, which is why the technically correct names are Homo sapiens sapiens and Homo sapiens neanderthalensis.

The presence of the human hyoid bone, throat architecture and DNA (FoxP2 protein) required for speech indicates that they might have had a language. [4] Earlier Homo species did not have these characteristics. [5] They made shelters, symbolic and ornamental objects, and left flowers or other mementos on graves. Many Neanderthal sites have awls, which indicates that Neanderthals probably wore animal skin as clothing. They might have even made primitive flutes: a flutelike object was found in a fire pits dated 45 ka. Some Neanderthal fossils show signs of sickness and disabilities, which means they cared for the disabled.

Although some scholars think that Homo neanderthalensis intelligence was on par with Homo sapiens, recent genetic studies indicated that many genes responsible for human creativity and self-control are not found in Homo neanderthalensis. They may have been just as intelligent and symbolic in some ways, [6] [7] but there many genes oriented with humanness that Homo sapiens subsequently acquired in Africa after the split between Homo sapiens and Neanderthals.

Chris Stringer is an anthropologist and expert in human evolution. He argued that Homo sapiens fossils such as the Jebel Irhoud fossils from 300,000 years ago represented transitional Homo sapiens and that there were probably several branches prior to the time that Homo sapiens became anatomically modern 200,000 years ago.[8]

The evolution of anatomically modern humans (AMH) was gradual. There are many transitional skulls between archaic humans and Homo sapiens between 300,000 and 175,000 years ago in Africa. White et al. discovered well-preserved Homo sapiens craniums that were 160,000 years old in East Africa, which were intermediate between modern Homo sapiens and older African Homo species such as Homo erectus, and partial skeletons of anatomically modern humans that were 195,000 years old.[9] Africa was arid approximately 150,000 years ago and Homo sapiens groups were probably spread out and isolated; however, approximately 120,000 years ago, Africa became more humid, and there might have been gene flow between regions.

Zwir et al. stated when the different sets of “human” genes originated (below). They defined Homo sapiens and Neanderthal evolution as follows:[10] Neanderthals and Homo sapiens became isolated approximately 500,000 years ago, Neanderthal precursors appeared 430,000 years ago, but true Neanderthals did not appear until 130,000 years ago in Eurasia. They also stated that precursors of anatomically modern humans appeared between 320,000 (such as Jebel Irhoud) and 200,000 years ago, forming large social groups and trade networks, symbolic behavior, used art and ornamentation, and then anatomically modern humans appeared between 200,000 and 160,000 years ago in Eastern Africa. They also stated that modern behavior with imagination and diverse abilities appeared 100,000 years ago, but then unmistakably modern behavior appeared after 50,000 years ago.   

Many modern Homo sapiens have many genes associated with humanness that were not present in Neanderthals. Zwir et al. are medical researchers who correlate genomics with human temperament.[11] [12] They first identified genes in modern humans associated with human emotional reactivity, self-control, and self-awareness They then compared the presence or absence of these genes in Homo sapiens, Neanderthal, and chimpanzee genomes and found many of these genes missing in Neanderthals and chimpanzees.[13]

“Neanderthals had nearly the same genes for emotional reactivity as chimpanzees, and they were intermediate between modern humans and chimpanzees in their numbers of genes for both self-control and self-awareness. 95% of the 267 genes we found only in modern humans were not protein-coding, including many long-non-coding RNAs in the self-awareness network. These genes may have arisen by positive selection for the characteristics of human well-being and behavioral modernity, including creativity, prosocial behavior, and healthy longevity. The genes that cluster in association with those found only in modern humans are over-expressed in brain regions involved in human self-awareness and creativity…We conclude that modern humans have more than 200 unique non-protein-coding genes regulating co-expression of many more protein-coding genes in coordinated networks that underlie their capacities for self-awareness, creativity, prosocial behavior, and healthy longevity, which are not found in chimpanzees or Neanderthals.”[14]

Palma-Morales stated that the Neanderthal genes for self-awareness and self-control were halfway between humans and chimpanzees.[15] Zwir et al. identified the times when groups of genes emerged in the human genome as follows.

"The scientists were able to identify the regions of the brain in which those genes (and those with which they interacted) were overexpressed," they wrote.

"These regions are involved in human self-awareness and creativity, and include the regions that are strongly associated with human well-being and that appeared relatively recently."

Previously, the same team had identified a pool of 972 genes organized into three brain networks, the oldest—which relates to learning habits, social attachment and conflict resolution—dating back 40 million years.

The second network—which relates to intentional self-control—emerged 2 million years ago, while the newest, governing creative self-awareness, only emerged 100,000 years ago.” [16]

As with Zwir’s estimated time of the advent of human creativity, Marean placed it as between 135 ka and 75 ka.[17]

Some scientists think that there is evidence of modern thinking among Homo sapiens approximately 100,000 years old in two adjacent caves in Israel, Qafzeh and Skhul, which yielded eleven skeletons of anatomically modern humans in layers dated between 125 ka and 100 ka. There is evidence of shell beads in these caves in the levels occupied by AMH, which implies an appreciation of beauty and at least the beginnings of modern thinking. There are also graves, which seem to indicate a belief in the hereafter. The anatomically modern humans at Qafzeh and Skhul vanished approximately 100 ka.

Pena et al. defined the differences between humans and previous hominids and the effect of those differences on human success.

“Modern humans demonstrate greater creativity compared with other hominids, such as innovation, flexibility, depth of planning, and related cognitive abilities for symbolism and self-awareness. In modern human society, creativity is associated with positive accomplishments in many different fields such as workplace organization and scientific progress.” [18]

Genomic analysis indicates that all humans descended from a common male Homo sapiens ancestor who lived approximately 300 ka in Africa (Figure 6-20). A00 is a haplogroup from Western Cameroon that has the 300 ka estimated date of origin. A0, a subset of A00, is found in Bakola Pygmies, 8.3%, and in Berbers in Algeria.  The 300 ka estimate is based on the genomes of many individuals and groups in Africa and elsewhere. The estimate corresponds with the time of the first Homo sapiens fossils from Jebel Irhoud in Morocco (Figure 13-24). On the other side, all humans descended from a female ancestor who lived approximately 160 ka in Africa. With respect to God making “mankind” in the image of God, the timing of the last male and female common ancestors does not indicate a couple such as Adam and Eve; however, they may be significant since God might have added genes or and spiritual heart to common ancestors like these, which were then propagated in descendants.

Rito et al. stated that human creativity first began to emerge in the fossil record in southern Africa 100 ka. This probably refers to the Blombos Cave community, which the next chapter describes. These advanced humans then migrated to East Africa 70 ka, prior to leaving Africa.[19]

If the transformation to the image of God was a gradual biological process, then there was probably no one point when human DNA could be defined as bearing or not bearing the image of God. On the other hand, if God implanted a nonmaterial spirit or heart into humans at some point in the 2 million years of development, then this might be considered as the critical point at which humans were in the image of God.

References

[1] José-Miguel Carreteroa, Laura Rodrígueza, Rebeca García-Gonzáleza, Juan-Luis Arsuagab, Asier Gómez-Olivenciad, Carlos Lorenzob, et al., Stature estimation from complete long bones in the Middle Pleistocene humans from the Sima de los Huesos, Sierra de Atapuerca (Spain), Journal of Human Evolution (2012), 62(2): 242–255.

[2] There’s Something Weird About Neandertal DNA And It Might Be Our Fault. PBS eons. YouTube video at <https://youtu.be/J2FatwFjc-8>

[3] Posth, Cosimo, Christoph Wißing, Keiko Kitagawa, Luca Pagani, Laura van Holstein, Fernando Racimo, Kurt Wehrberger et al. "Deeply divergent archaic mitochondrial genome provides lower time boundary for African gene flow into Neanderthals." Nature communications 8, no. 1 (2017): 16046.

[4] D’Anastasio R, Wroe S, Tuniz C, Mancini L, Cesana DT, et al. (2013) Micro-Biomechanics of the Kebara 2 Hyoid and Its Implications for Speech in Neanderthals. PLoS ONE 8(12): e82261. doi:10.1371/journal.pone.0082261

[5] Ed Young, Surprise! 20 Percent of Neanderthal Genome Lives On in Modern Humans, Scientists Find, National Geographic, January 29, 2014. Accessed at http://news.nationalgeographic.com/news/2014/01/140129-neanderthal-genes-genetics-migration-africa-eurasian-science/

[6] Jaubert, Jacques, Bruno Maureille, and Marco Peresani. "Spiritual and symbolic activities of Neanderthals." In Updating Neanderthals, pp. 261-274. Academic Press, 2022.

[7] Berwick, Robert C., Marc D. Hauser, and Ian Tattersall. "Neanderthal language? Just-so stories take center stage." Frontiers in psychology 4 (2013): 671.

[8] Stringer, Chris. "The origin and evolution of Homo sapiens." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1698 (2016): 20150237.

[9] McDougall I., F. Brown, J. Fleagle. 2005. Stratigraphic placement and age of modern humans from Kibish, Ethiopia. Nature. 433(7027):733-6.

[10] Zwir, Igor, C. Del-Val, Mirka Hintsanen, K. M. Cloninger, R. Romero-Zaliz, A. Mesa, J. Arnedo et al. "Evolution of genetic networks for human creativity." Molecular psychiatry 27, no. 1 (2022): 354-376.

[11] Zwir, Igor, Javier Arnedo, Coral Del-Val, Laura Pulkki-Råback, Bettina Konte, Sarah S. Yang, Rocio Romero-Zaliz et al. "Uncovering the complex genetics of human temperament." Molecular psychiatry 25, no. 10 (2020): 2275-2294.

[12] Zwir, Igor, Coral Del-Val, Javier Arnedo, Laura Pulkki-Råback, Bettina Konte, Sarah S. Yang, Rocio Romero-Zaliz et al. "Three genetic–environmental networks for human personality." Molecular Psychiatry 26, no. 8 (2021): 3858-3875.

[13] Zwir Nawrocki, Jorge Sergio Igor, María Coral Del Val Muñoz, Rocio Celeste Romero Zaliz, Francisco Javier Arnedo Fernández, and Alberto Acosta Mesas. "Evolution of genetic networks for human creativity." (2021).

[14] Zwir, Human creativity.

[15] Palma-Morales, Marta, Ana Mateos, Jesús Rodríguez, Rafael A. Casuso, and Jesús R. Huertas. "Food made us human: Recent genetic variability and its relevance to the current distribution of macronutrients." Nutrition 101 (2022): 111702.

[16] Medical Express. 'Creative' genes gave Homo sapiens edge over Neanderthals: study. April 23, 2021. Accessed Oct 12, 2023. <https://medicalxpress.com/news/2021-04-creative-genes-gave-homo-sapiens.html>

[17] Marean, Curtis W., Miryam Bar-Matthews, Jocelyn Bernatchez, Erich Fisher, Paul Goldberg, Andy IR Herries, Zenobia Jacobs et al. "Early human use of marine resources and pigment in South Africa during the Middle Pleistocene." Nature 449, no. 7164 (2007): 905-908.

[18] Peña, Javier, Makii Muthalib, Agurne Sampedro, Mafalda Cardoso‐Botelho, Oihana Zabala, Naroa Ibarretxe‐Bilbao, Acebo García‐Guerrero, Leire Zubiaurre‐Elorza, and Natalia Ojeda. "Enhancing creativity with combined transcranial direct current and random noise stimulation of the left dorsolateral prefrontal cortex and inferior frontal gyrus." The Journal of Creative Behavior 57, no. 1 (2023): 65-81.

[19] Rito, Teresa, Daniel Vieira, Marina Silva, Eduardo Conde-Sousa, Luísa Pereira, Paul Mellars, Martin B. Richards, and Pedro Soares. "A dispersal of Homo sapiens from southern to eastern Africa immediately preceded the out-of-Africa migration." Scientific reports 9, no. 1 (2019): 4728.

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Neanderthal man reconstruction, Natural History Museum, London. Credit: Werner Usthorf. Used here per CC BY-SA 3.0