Another Creationist Falsehood Exposed - A Beneficial Mutation Helped Early Pastoralists Expand Their Range

Horses of the Central Asian Steppe

© A. Senokosov

Milk Enabled Massive Steppe Migration | Max Planck Institute for the Science of Human History

The problem with Creationist child-like black vs white thinking is that their assertions are usually very easy to refute, although that rarely, if ever, results in a change of mind. One easily debunkable claim, for example, is that all mutations are harmful.

This demonstrable falsehood forms the basis of Michael J. Behe's recent attempt to replace his failed intelligent [sic] design hoax with his 'devolution' nonsense, in which he tries to argue that, although mutations arise and are inherited, just like the TOE says, but, because they are always harmful, this is 'devolution' not evolution and so is a degeneration from the initial perfection of creation, consistent (of course) with the Bible narrative

a–c, Eneolithic (a), Early Bronze Age (b) and Middle–Late Bronze Age (c) sites in the Pontic–Caspian region, showing the number of individuals with a positive dairy identification out of the total number of individuals with preserved ancient proteins for each site. Strong evidence of preservation of equine or ruminant milk protein identifiers are depicted with black animal icons; the single individual with equivocally identified casein peptides is shown with a grey icon. For a map of all sites (including those without preserved proteins), see Supplementary Fig. 1. Base maps were created using QGIS 3.12 (https://qgis.org/en/site/), and use Natural Earth vector map data from https://www.naturalearthdata.com/downloads/. The horse image is reproduced from ref., ³³; sheep silhouette, public domain (https://thenounproject.com/icon/12538/).

of 'The Fall'. Needless to say, Behe is silent on the problem of how to explain a harmful mutation increasing in the species gene pool.

Behe's problem, however, is that this is very easily debunked with real examples, although that never troubles devoted Creationists who will either be blissfully and diligently unaware of the real examples, or will have one or more strategies for dismissing them.

Here though, is one which will be difficult to ignore because it is still present in descendants today and they are very probably enjoying its benefits. It can't possibly be dismissed as harmful because it is so manifestly beneficial and even central to so much of Western food culture. I'm talking about the mutations which caused lactase persistence, which was regarded as so 'normal' that its absence, which causes lactose intolerance was regarded as the abnormal trait, causing what was regarded as a dietary disorder in those without the mutation.

For more information on lactase Persistence/lactose intolerance and its role in the evolution of modern humans, see, Human Evolution in Progress.

The evolution of lactase persistence, i.e. the retention of the ability to manufacture the enzyme, lactase, into adulthood and so digest dairy products such as milk, cheese, butter, etc, which is 'normally' lost in childhood, is almost certainly the key mutation that led to the massive expansion of Early Bronze Age pastoralists from the steppes of Central Asia into Western Europe, as revealed in a paper by researchers from the Max Planck Institute for the Science of Human History, Jena, Germany.

Basing their research on an examination of the tartar (dental calculus) on the teeth of preserved skeletons, they have shown that the abrupt (in geological terms) inclusion of milk in the diet of the people known as the Yamnaya coincided with the beginning of the expansion of their range, carrying their genes, including that for lactase persistence deep into Western Europe and into Scandinavia.

From the Max Planck Institute for the Science of Human History news release:

The pattern was incredibly strong. The majority of pre-Bronze Age Eneolithic individuals we tested – over 90% - showed absolutely no evidence of consuming dairy. In contrast, a remarkable 94% of the Early Bronze Age individuals had clearly been milk drinkers…

What we see here is a form of cultural revolution. Early Bronze Age herders clearly realized that dairy consumption offered some fundamental benefits and once they did, vast steppe expansions of these groups across the steppe became possible.

Dr. Shevan Wilkin, lead author
Palaeoproteomics specialist
Department of Archaeology
Max Planck Institute for the Science of Human History, Jena, Germany

From the Xiongnu to the Mongols, the pastoralist populations of the Eurasian steppe have long been a source of fascination. Amongst the earliest herding groups in this region were the Yamnaya, Bronze Age pastoralists who began expanding out of the Pontic-Caspian steppe more than 5000 years ago. These Bronze Age migrations resulted in gene flow across vast areas, ultimately linking pastoralist populations in Scandinavia with groups that expanded into Siberia.

Just how and why these pastoralists travelled such extraordinary distances in the Bronze Age has remained a mystery. Now a new study led by researchers from the Max Planck Institute for the Science of Human History in Jena, Germany has revealed a critical clue and it might come as a surprise. It appears that the Bronze Age migrations coincided with a simple but important dietary shift – the adoption of milk drinking.

Our results won’t make everyone happy, but they are very clear. We see a major transition to dairying right at the point that pastoralists began expanding eastwards… Steppe populations were no longer just using animals for meat, but exploiting their additional properties –milking them and using them for transport, for example.

Professor Nicole Boivin, senior author
Director of the Department of Archaeology
Max Planck Institute for the Science of Human History, Jena, Germany

The researchers drew on a humble but extraordinary source of information from the archaeological record – they looked at ancient tartar (dental calculus) on the teeth of preserved skeletons. By carefully removing samples of the built-up calculus, and using advanced molecular methods to extract and then analyse the proteins still preserved within this resistant and protective material, the researchers were able to identify which ancient individuals likely drank milk, and which did not.

Their results surprised them. “The pattern was incredibly strong,” observes study leader and palaeoproteomics specialist Dr. Shevan Wilkin, “The majority of pre-Bronze Age Eneolithic individuals we tested – over 90% - showed absolutely no evidence of consuming dairy. In contrast, a remarkable 94% of the Early Bronze Age individuals had clearly been milk drinkers.”

The research also revealed that these people drank milk from a variety of species, including horses, in addition to cow, sheep and goat. This has implications for the story of the domestication of the horse. Examining the tooth tartar of a couple of individuals from the 3500-year-old site of Botai in Kazakhstan showed no evidence of milk consumption. This site is also associated with the wild Central Asian Przewalskii horses whose remains have been excavated there. This suggests that Przewalskii horses were not the ancestor of domestic horses. Instead, horse domestication – and the drinking of horse milk – likely began in the Pontic Caspian steppe.

The team's findings are published, open access, in Nature:

Abstract

During the Early Bronze Age, populations of the western Eurasian steppe expanded across an immense area of northern Eurasia. Combined archaeological and genetic evidence supports widespread Early Bronze Age population movements out of the Pontic–Caspian steppe that resulted in gene flow across vast distances, linking populations of Yamnaya pastoralists in Scandinavia with pastoral populations (known as the Afanasievo) far to the east in the Altai Mountains^1,2 and Mongolia³. Although some models hold that this expansion was the outcome of a newly mobile pastoral economy characterized by horse traction, bulk wagon transport^4,5,6 and regular dietary dependence on meat and milk⁵, hard evidence for these economic features has not been found. Here we draw on proteomic analysis of dental calculus from individuals from the western Eurasian steppe to demonstrate a major transition in dairying at the start of the Bronze Age. The rapid onset of ubiquitous dairying at a point in time when steppe populations are known to have begun dispersing offers critical insight into a key catalyst of steppe mobility. The identification of horse milk proteins also indicates horse domestication by the Early Bronze Age, which provides support for its role in steppe dispersals. Our results point to a potential epicentre for horse domestication in the Pontic–Caspian steppe by the third millennium BC, and offer strong support for the notion that the novel exploitation of secondary animal products was a key driver of the expansions of Eurasian steppe pastoralists by the Early Bronze Age.

Wilkin, Shevan; Ventresca Miller, Alicia; Fernandes, Ricardo; Spengler, Robert; Taylor, William T.-T.; Brown, Dorcas R.; Reich, David; Kennett, Douglas J.; Culleton, Brendan J.; Kunz, Laura; Fortes, Claudia; Kitova, Aleksandra; Kuznetsov, Pavel; Epimakhov, Andrey; Zaibert, Victor F.; Outram, Alan K.; Kitov, Egor; Khokhlov, Aleksandr; Anthony, David; Boivin, Nicole
Dairying enabled Early Bronze Age Yamnaya steppe expansions.
Nature (2021). DOI: 10.1038/s41586-021-03798-4

Copyright: © 2021 The authors. Published by Springer Nature Ltd.
Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0)

So, lactase persistence, which is a mutant form of the 'normal' condition in which the ability to make lactase is lost normally during the second year of life, so weaning the baby off breast feeding (which had been acting as a natural contraception by stimulating the release of prolactin) and allowing the mother to become pregnant again, allowed the baby to be fed on milk from alternative sources, and to provide adult humans with a nutritious food, had massive benefits to the carrier population. In this case, it allowed for a massive expansion both in population and in territory. And that mutation is still so beneficial to modern humans that the 'normal' form is regarded as a digestive disorder and can be a major handicap for its carriers in a Western society and other cultures in which dairy products play a major part in the diet.

It will be interesting to see how Creationists, especially those fooled by Michael J Behe's latest attempt to fit the facts into Bible mythology yet still present it as real science, handle this news. My guess is that they will either ignore it all together or will rubbish the science in some way or will invoke some equally infantile 'argument' such as "Were you there?".

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