April 2, 2021 | Jerry Bergman

Denisovans Were Modern People

The Mysterious Denisovans: A New Study Provides
More Evidence that They Were a Modern People Group

 

by Jerry Bergman, PhD

Introduction

The Denisovans are generally regarded by evolutionists as a group of “archaic subspecies of H. sapiens” related to the Neanderthals. First identified in 2008 in the Denisova Cave, a cave named after Denis (Dyonisiy), a Russian hermit who lived there in the 18th century.[1] The cave is located in south-central Siberia, near the border with Kazakhstan, China, and Mongolia. The evidence we have of Denisovans, according to University of Adelaide professor João C. Teixeira, is very limited:

In contrast to our other cousins the Neanderthals, which have an extensive fossil record in Europe, the Denisovans are known almost solely from the DNA record. The only physical evidence of Denisovan existence has been part of a finger bone and some other fragments found in the Siberia cave and, more recently, a piece of jaw found in the Tibetan Plateau.[2]

A partial jawbone from a Denisovan. From Wikimedia Commons.

The Newest Research on Denisovan DNA

Teixeira et al. published new findings in Nature Ecology & Evolution (22 March 2021). They analyzed the DNA in these small bone fragments, including the hominin fossil record of Island Southeast Asia (ISEA), concluding that

contemporary human populations across ISEA carry distinct genomic traces of ancient interbreeding events with Denisovans—a separate hominin lineage that currently lacks a fossil record in ISEA. To query this apparent disparity between fossil and genetic evidence, we performed a comprehensive search for super-archaic introgression in >400 modern human genomes, including >200 from ISEA. Our results corroborate widespread Denisovan ancestry in ISEA populations, but fail to detect any substantial super-archaic admixture signals compatible with the endemic fossil record of ISEA.[3]

One of the molars from a Denisovan. From Wikimedia Commons.

The team was able to confirm previous results showing high levels of Denisovan ancestry in the region where the Denisovan fossils were found.[4] The finding of “distinct genomic traces of ancient interbreeding events with Denisovans” is evidence that they were one species with modern humans. Other genetic analysis has found similar results.[5]

Meyer et al. in 2012, publishing in Science, determined that no new genes compared to modern humans have been detected in the Denisovans. A total of 34 new gene variants were found in which the protein sequence differs only in 1–2 amino acids from modern human protein sequences in areas known to cause diseases.[6] This also supports the position that Denisovans and humans both belonged to the same created kind.

The gene differences are all related to illnesses resulting from base substitutions. Specifically, these genes have been linked to autism and language disorders (genes ADSL and CNTNAP2). Gene EVC2 causes Ellis-Van Creveld syndrome and Taurodontism syndrome, resulting in enlargement of the tooth and pulp chamber at the expense of the roots.

It is plausible that these genes had detrimental mutations, causing illness in the now-extinct Denisovans.

Problems in Paleontology

The judgments about Denisovans are based primarily on genetic evidence. The question that needs to be considered is whether researchers can rely on genetic analysis of admittedly very old fossils.[7] Common problems in genetic comparisons include contamination (because all genetic comparisons should be done in a level-5 clean room), PCR-induced mutations, and data bias. Denisovan genetic variety is quite large, fully seven times that of Neanderthals.[8] This creates uncertainties when classifying them as an archaic subspecies of  Neanderthals based on their mitochondrial DNA.

The finger fragment of a Denisovan. From Wikimedia Commons.

Another concern results from a difficulty common in paleontology: namely, making judgments from miniscule evidence, in this case a finger fragment, a piece of a jaw, and three molars (see figures). I assume that good evidence exists to conclude that these small fragments were not a part of the Russian hermit or his relatives who were known to have lived in the cave. Another problem is the fragments found are from at least two different individuals, an adolescent female and an adult male.[9] Aside from these possible concerns, the evidence that Denisovans and humans both belonged to the same created kind appears valid.

Neanderthals and Humans Both Belonged to the Same Created Kind

Observers should be suspicious of claims that Denisovans are a species of Neanderthal. Recall that for close to 150 years Neanderthals were believed to be an evolutionary link between modern humans and our ape-like ancestors (see next two figures). It is only recently that they were confirmed to be modern humans, not an inferior race on the way to becoming fully modern. Likewise, it now appears that the Denisovans are not an archaic subspecies of Neanderthals as once claimed, but fully modern humans as well. Teixeira et al. also decided that at least two endemic species besides Denisovans —Homo luzonensis and Homo floresiensis—were present around the same time that anatomically modern humans lived in the region.[10] In fact, H. floresiensis (or “Hobbits) could be a southern branch of Denisovans, according to Live Science. This is additional evidence that all these fossils were simply people groups within humankind.

Textbooks have long included distorted images to prove human evolution, using evidence that was later reinterpreted: e.g., Neanderthals are no longer considered “missing links” but a people group within Homo sapiens.

 

Evidence of Their Human Cognitive Abilities

Based on nothing but the fragmentary fossil evidence noted above, claims of Denisovan cognitive capabilities and even their population dynamics have been made. It is obviously premature to draw conclusions from the few fossil fragments collected, but human artifacts found in Denisova Cave support the belief they were peculiar groups within Homo sapiens. The artifacts include decorations made of bone, mammoth tusks, ostrich eggs, mollusk shells, pendants produced from animal teeth, and fragments of a bracelet constructed of polished dark-green chloritolite.[11] Tools were also found in the cave, including needles with drilled-out eyes and awls. If these artifacts were, in fact, made by Denisovans, it supports the case that they were modern people.

Summary

The evidence paints a picture that Denisovans were another people group related to the Neanderthals that interbred with modern humans. More research is needed to confirm this early conclusion.

Another biased textbook image that used Neanderthals to prove human evolution.

References

[1] Gibbons, A. 2011. Who were the Denisovans? Science 333(6046):1084–1087, August 26.

[2] Quoted in Kelly Brown. 2021. The University of Adelaide NEWSROOM.  New Evidence in Search for the Mysterious Denisovans, March 23. https://www.adelaide.edu.au/newsroom/news/list/2021/03/23/new-evidence-in-search-for-the-mysterious-denisovans

[3] Teixeira, João C., et al. 2021. Widespread Denisovan ancestry in Island Southeast Asia but no evidence of substantial super-archaic hominin admixture. Nature Ecology & Evolution, March 22. https://www.nature.com/articles/s41559-021-01408-0.

[4] Teixeira, 2021.

[5] Gokhman, D., Lavi, E., Prüfer, K. et al. 2014, Reconstructing the DNA methylation maps of the Neandertal and the Denisovan. Science 344(6183):523–527, May 2. | doi: 10.1126/science.1250368.

[6] Meyer, M., Kircher, M., Gansauge, M.T. et al. 2012. A high-coverage genome sequence from an archaic Denisovan individual. Science 338(6104):222–226, October 12. | doi: 10.1126/science.1224344.

[7] Criswell, D. 2009. Neandertal DNA and modern humans. Creation Research Society Quarterly 45(4):246–254, 2009.

[8] Meyer, M.; Fu, Q.; Aximu-Petri, A., et al. 2014. A mitochondrial genome sequence of a hominin from Sima de los Huesos. Nature 505(7483):403–406, December 4. | doi:10.1038/nature12788.

[9] Reich, D.; Green, R. E.; Kircher, M., et al. 2010. Genetic history of an archaic hominin group from Denisova Cave in Siberia.  Nature 468(7327):1053–1060, December 22.

[10] Teixeira, 2021.

[11] Derevianko, A.P.; Shunkov, M.P., and Volkov, P.V. 2008. A Paleolithic bracelet from Denisova cave. ArchaeologyEthnology& Anthropology of Eurasia 34(2):13–25, June.  | doi:10.1016/j.aeae.2008.07.002.


Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,500 college libraries in 27 countries. So far over 80,000 copies of the 40 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.

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