January 14, 2013

NEANDERTHAL DESCENDANTS

According to evolutionary paleoanthropologists Neanderthals went extinct about 30,000 years ago, with their last individuals living in southern Spain and Gibraltar. In the light of what we know about their anatomy, genetics, and culture, what is their relationship to modern humans? Did Neanderthals leave direct descendants? Ideas about the fate of this group of humans are controversial and researchers do not agree. There are basically three ideas or interpretations.

One interpretation is that all modern humans have a relatively recent origin (~150,000 years ago) in Africa, and that Homo sapiens and Homo neanderthalensis (now extinct) represented different evolutionary lineages living in different continents. According to this view, Homo neanderthalensis lived in Asia and Europe and went extinct before Homo sapiens developed from an African ancestor that migrated to the northern continents.[1] Modern humans never coexisted with Neanderthals, had no sexual interaction with them and therefore did not inherit any genetic trait from them.[2] Neanderthals left no descendants. In this view, extinction would have occurred due to climate deterioration, lack of resources, and the expanding populations of modern humans that pushed Neanderthals to the margins of the continent.

Other researchers believe that the Neanderthals were the ancestors of early modern humans.[3] Some archaeological evidence suggests that the last Neanderthals disappeared in western Europe around 35,000 to 34,000 years before present (BP) (radiocarbon dates) or 30,000 years BP depending on dating methods. The first anatomically modern humans appeared in France around 39,000 years BP, and, according to this theory, introduced new technologies (tools) and art, and thus Neanderthals could represent the ancestors of modern Europeans. Neanderthals would gradually merge into modern-looking humans and their particular anatomical traits simply disappear.[4] An important problem with this idea is that If Neanderthals are associated with art and tools, it becomes difficult to claim they learned them just as they were going extinct.

A third group of researchers proposes that continuity of certain anatomical traits between late Neanderthals and the first fossil humans, both found in central Europe, suggests a genetic flow between Neanderthals and modern humans, at least in some areas. In this view, modern Homo sapiens migrated north from Africa absorbing the Neanderthals, and at about 30,000 years ago European and Asian humans would have both African and Neanderthal ancestors. Some paleoanthropologists say, however, that because morphological differences between Neanderthals and modern humans are so remarkable, it is difficult to see the first modern European and Asian humans as the descendants of the Neanderthals.[5] The controversy continues.

At this time, paleoanthropologists seem to have a consensus that Neanderthals and modern humans overlapped in time, but they are divided on whether Neanderthals and modern humans came in contact and whether they interbred. Until recently, fossil bones and artifacts were the only material researchers could obtain from Neanderthals. The studies of morphological traits of present-day humans and ancient modern humans have been used as evidence both for and against genetic exchange between Neanderthals and alleged ancestors of modern European humans.[6] But researchers have been able to obtain DNA from ancient bones and are now using molecular techniques to determine whether Neanderthals once interbred with Homo sapiens. If such exchange of genes occurred between the two races, then we would be able to find evidence for that in modern human DNA sequences.

Only recently has nuclear DNA been extracted and analyzed from ancient Neanderthal bones. The breakthrough finding occurred at the Max Planck Institute in Germany where part of the genome (nuclear) DNA from the bones of three Neanderthal women found in Croatia’s Vindija Cave was extracted. The result of the sequencing of this nuclear DNA suggests that the genomes of non-African present-day humans contain around 1-4% of DNA sequence inherited from Neanderthals. The researchers found that “Neanderthals fall within the variation of present-day humans for many regions of the genome.”[7] This means that, genetically speaking, Neanderthals are not totally extinct as most researchers had assumed so far, but their DNA occurs in many present-day humans. Put another way, most people can likely trace some of their genome back to Neanderthals. Furthermore, research by Noonan and colleagues found that “the Neanderthals and human genomes are at least 99.5% identical.”[8]

Another striking finding is that, genome-wise, Neanderthal sequences studied so far are closer to non-African than to African present-day humans, and are as closely related to humans in East Asia and the Pacific islands as to central or western European, “even though morphologically recognizable Neanderthals exist only in the fossil record of Europe and western Asia.”[9] Green and colleagues explain this feature as the result of interbreeding of Neanderthals with ancient humans in the Middle East before the expansion of the latter into Eurasia, which left a small amount of Neanderthal genome –between 1 and 4 percent– in the modern human genome.

For many researchers, these findings change the way Neanderthals are seen in the history of humanity. It was thought that Neanderthals were extinct humans that had no connection with modern humans at all, whereas now many paleoanthropologists are accepting the idea that Neanderthals mixed with early modern humans and left their genetic imprint on the latter. Several questions arise from these recent discoveries related to molecular genetics:

Are Neanderthals, despite their particular anatomical features, really different from modern humans? Did Neanderthals and modern humans interbreed? And if they did, what kind of fossil record could we find? In other words, if such genetic exchange happened, we would expect to find hybrid intermediates in the fossil record.

THE NEANDERTHAL NEXT DOOR

The discovery of Neanderthal remains occurred just three years before the publication of Darwin’s Origin of Species in 1859. Although it seemed to provide initial evidence for Darwinian evolution, Darwin himself did not use it either in his first book or in the later The Descent of Man.[10] Interest in Neanderthals arose in the early 20^th century when scientists studied some of the skulls in order to find possible affinities with chimpanzees and highlight the superiority of the European white man.[11] Neanderthals were initially portrayed as deformed, brutish human ancestors, but this view has been changing toward a gentler picture, as many fossils have been unearthed in Europe, Middle East, and Asia. In the last decades, meticulous examination of the skeletal remains using advanced techniques of microscopy, X-ray, X-ray computed tomography, and others, has modified the simian appearance that Neanderthals had in earlier reconstructions toward a sophisticated reconstruction that bears similarities with humans inhabiting some very cold areas in modern times.

An increasing number of paleoanthropologists are claiming that Neanderthals were fully human individuals. As an example, Jean-Louis Heim asserts, “Neanderthal man is neither… an aberrant human species nor an outcast of our evolution for having lived in a particular environment that would have lent certain anatomical traits that formerly were thought of as “rough”, or even beast-like. He is, first of all, a true human, with anatomical particularities inherited from human form that preceded him….”[12]

The occurrence of modern human remains interstratified with Neanderthal remains, and the clear archaeological evidence that Neanderthals were using similar tools as modern humans and behaving like them[13] clearly suggest that the two groups did co-exist in time and space and were not separate species.

Some people have suggested that if we could dress a Neanderthal man with a suit and a tie, perhaps we would not find any significant differences with any of our neighbors, i. e., the differences would not as great as we may have thought. His aspect would be of a robust, short man, with short arms and legs but stocky and wide chest, and a ridge of bone above the eyes, which gives him a ‘primitive’ look. In fact, his overall physical appearance might be similar to Eskimos and some other modern human populations.

IMPLICATIONS WITHIN A BIBLICAL FRAMEWORK

The fossil record of hominid and human fossils seemingly fits an evolutionary lineage for the origin of modern humans. The order in which these fossil hominids and humans appear in the sedimentary record seem to suggest a gradual appearance of more ‘advanced’ humans along a period of hundreds of thousands of years according to the evolutionary time scale. Neanderthals would be one of the last steps in this gradual evolution. Researchers discuss the role and position of Neanderthals in this alleged evolutionary process and debate whether they went extinct before, during or after anatomically modern humans colonized the northern hemisphere, and if the former interbred with the latter. However, many recent studies, ranging from genetics to the analysis of Neanderthal technology and culture suggest that Neanderthals might be understood within a different scientific framework.

The fossil record also shows how changeable the evolutionary scenarios are for the rise and diversification of humans. A close examination of the evidence and the assumptions behind the evolutionist story for the origin of modern man raises some questions that expose the weakness of the evolutionary model.

• Some evidence suggests that both Neanderthals and anatomically modern humans lived side-by-side for several thousand years at least in some areas, and even used the same shelters. Is it possible that they inhabited the same region and never intermarried? This questions signal to the idea that Neanderthals did not evolve throughout hundreds of thousands of years, but had a much more recent origin. It is difficult to fathom such a long period of time without any interbreeding between the two human groups that lived in the same continent at the same time. As indicated above, this fact is dividing evolutionists, some of whom still hold that the two human groups did not engage in reproductive interaction, whereas other scientists say that it is impossible to rule out some admixture between the two groups.
• Is it possible that Neanderthals and modern humans lived in Europe and western Asia for tens of thousands of years and yet did not populate the rest of the world (Africa, Asia, and American continents)? This is indeed a real possibility. We know how rapidly human populations grow even in very harsh conditions. Why are there no fossil Neanderthals in, for example, southern Africa? If there were warmer territories available in southern Asia and Africa, why were they not occupied? We also know that humans tend to move around freely. Some argue that Neanderthals could not occupy regions already occupied by other ‘advanced’ human forms but that is not an explanation derived from factual evidence, but from the assumption of evolution.
• The archaeological findings indicate that Neanderthals were not stupid and/or underdeveloped. They were smart enough to hunt mammoths, deer, bison and other large animals. The same applies to other humans in later prehistoric periods, which depicted their activities in remarkable hunting scenes that decorate the walls of the rock shelters and caves where they lived. Some of those paintings show an elaborate, thorough presentation of scenes, which are very difficult to replicate even by highly skilled modern artists. It is difficult to imagine that all of that happened for several tens of thousands of years without much improvement. Why did they develop sophisticated hunting techniques but never learned to tame horses or tame other wild animals? Archaeologists used to believe that these Neanderthals and ‘early modern humans’ were nomads, but now scientists assert, based on the remains found in caves, that they were sedentary (i.e. non-nomadic), at least for long periods of time. Assuming that is true, why did Neanderthal people live in caves for so long instead of building houses with stone or wood? If they had been inhabiting the earth for tens or hundreds of thousands of years they would be expected to build some structures, unless one assumed the evolutionary scenario, which, as we have seen, is riddled with problems in regards to Neanderthals. Why did it take so many thousands of years to domesticate horses, cows, and other animals, and build permanent shelters? Maybe the answer is there was no such a period of so many thousands of years.

The Bible may provide a framework in which these questions may be answered. Humans (and other life forms) have not been on Earth for so long. We read in Genesis 11 that post-Flood people scattered after Babel into distinct family clans onto many areas of the continents. It seems that several groups remained in the Middle East-Anatolian Peninsula area and built cities, developed complex writing systems, agriculture, and political and social laws. Groups that emigrated to Europe and northern Asia faced very harsh conditions due to the Ice Age, which probably delayed the development of agriculture, writing, and the construction of permanent settlements. Perhaps, Neanderthals arrived first in Europe and were followed by other human groups, although all are descendants of Noah. Perhaps, Neanderthals are pre-Babel humans that did not settle on the plain of Shinar (Genesis 11:2); but instead wandered east and west into unknown territory developing their own culture, technology, art and organization, which they carried with them as they migrated. This scenario eliminates the need for long periods of time spanning tens of thousands of years for the arrival and dominance of modern humans in Europe. A short-chronology, spanning a few hundred years after the Genesis Flood may better explain the genetic similarity between Neanderthals and present-time humans, many of the archaeological findings and the culture associated with the Neanderthal people.

This interpretation about who the Neanderthal people were and their origin is a possibility within a creationist, post-Flood scenario. More findings, research and study will help to elucidate what exactly this group of people was and what happened to them. Meanwhile, we should not make assumptions about Neanderthal either a point of scientific dogma or of religious faith.

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Raul Esperante

Geoscience Research Institute

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[1] This is called the “Out-of-Africa” model for human origins. The common ancestry could have been Homo heidelbergensis, based on traits in the tibia and teeth excavated in the Boxgrove site, Sussex, England, or Homo antecessor, found in northern Spain and dated to about 800 000 years BP.

[2] This view is held by, among others, William W. Howells, C. B. Stringer, and Bernard Vandermeersch.

[3] M. H. Wolpoff, of the University of Michigan, supports this view.

[4] This is called the “Multiregional Model” of human origins. It suggests that in the last 1 million years only one species of Homo sapiens existed, with different regional lineages interchanging genes and evolving toward modern humans.

[5] This view is held by F. H. Smith, Anne-Marie Tillier, Jean-Jacques Hublin, and Erik Trinkaus, although there is no agreement as to the relevance and scope of the genetic exchange. See Trinkaus 1990, p. 1159.

[6] Trinkaus, E., Moldovan, O., Milota, S., Bîlgăr, A., Sarcina, L., Athreya, S., Bailey, S.E., Rodrigo, R., Mircea, G., Higham, T., Ramsey, C.B. and van der Plicht, J., 2003. An early modern human from the Pestera cu Oase, Romania. Proceedings of the National Academy of Sciences, 100(20): 11231-11236. Zilhão, J., 2006. Neandertals and moderns mixed, and it matters. Evolutionary Anthropology: Issues, News, and Reviews, 15(5): 183-195. Bailey, S.E., Weaver, T.D. and Hublin, J.-J., 2009. Who made the Aurignacian and other early Upper Paleolithic industries? Journal of Human Evolution, 57(1): 11-26.

[7] Green, R.E., Krause, J., Briggs, A.W., Maricic, T., Stenzel, U., Kircher, M., Patterson, N., Li, H., Zhai, W., Fritz, M.H.-Y., Hansen, N.F., Durand, E.Y., Malaspinas, A.-S., Jensen, J.D., Marques-Bonet, T., Alkan, C., Prüfer, K., Meyer, M., Burbano, H.A., Good, J.M., Schultz, R., Aximu-Petri, A., Butthof, A., Höber, B., Höffner, B., Siegemund, M., Weihmann, A., Nusbaum, C., Lander, E.S., Russ, C., Novod, N., Affourtit, J., Egholm, M., Verna, C., Rudan, P., Brajkovic, D., Kucan, Ž., Gušic, I., Doronichev, V.B., Golovanova, L.V., Lalueza-Fox, C., de la Rasilla, M., Fortea, J., Rosas, A., Schmitz, R.W., Johnson, P.L.F., Eichler, E.E., Falush, D., Birney, E., Mullikin, J.C., Slatkin, M., Nielsen, R., Kelso, J., Lachmann, M., Reich, D. and Pääbo, S., 2010a. A draft sequence of the Neandertal genome. Science, 328(5979): 710-722. P. 716. The sequence assembled covers about 60% of the entire genome.

[8] Noonan, J.P., Coop, G., Kudaravalli, S., Smith, D., Krause, J., Alessi, J., Chen, F., Platt, D., Pääbo, S., Pritchard, J.K. and Rubin, E.M., 2006. Sequencing and analysis of Neanderthal genomic DNA. Ibid., 314(5802): 1113-1118.

[9] Green et al, 2010.

[10] Actually, he seems to suggest that the large size of the Neanderthal skull placed them outside the evolutionary lineage toward humans. See Darwin, C. R. 1871. The Descent of Man, and Selection in Relation to Sex. London: John Murray. Volume 1. 1st edition, p. 146.

[11] Heim, J.-L., 1997. Lo que nos dice la nariz de un Neandertal. Mundo Científico(177): 237-241.

[12] Heim, p. 238.

[13] Shipman, 2008, p. 14242.