Evolution Intelligent Design

Smithsonian Magazine: Why Did Europeans Evolve Into Becoming Lactose Tolerant?

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Famine and disease from millennia ago likely spurred the rapid evolution of the trait on the continent.

Brian Handwerk writes:

Just 5,000 years ago, even though it was a part of their diet, virtually no adult humans could properly digest milk. But in the blink of an evolutionary eye northern Europeans began inheriting a genetic mutation that enabled them to do so. The trait became common in just a few thousand years, and today it’s found in up to 95 percent of the population. By piecing together Neolithic pottery fragments and ancient human genomes, scientists may have solved the riddle of how European lactose tolerance evolved.

Milk Being Poured
Based on the remnants left on pottery fragments, researchers can say northern Europeans have been drinking milk for 9,000 years.  Seksan Mongkhonkhamsao via Getty Images

In a study published today in Nature, researchers compared archaeological evidence for 9,000 years of European milk use with genetics, and found an unusually rapid, evolution of lactose tolerance among Europeans well after they first started consuming the beverage. The authors suggest that something more extreme than regular milk consumption drove the genetic change. Exceptional stressors like famines and pathogens may have exacerbated milk’s typically mild gastrointestinal effects on the lactose intolerant, creating deadly bouts of diarrhea and dehydration while making the ability to digest milk extra valuable.

“It rewrites the textbooks on why drinking milk was an advantage,” says lead author Richard Evershed, director of the Biogeochemistry Research Center at the University of Bristol. “In order to evolve a genetic mutation so quickly, something has to kill off the people that don’t carry it.”

Almost all babies around the world are born with the ability to digest lactose—after all, it’s found in breast milk. But about two-thirds of adults can no longer digest the natural milk sugar because the production of a milk-digesting enzyme called lactase switches off after they’ve finished weaning. That’s why the majority of the world’s adult population is lactase non-persistent, otherwise known as lactose intolerant.

The other third of the world’s adult population has evolved lactose tolerance, meaning they keep producing lactase, and that’s particularly true among groups like those of northern European descent.

“When you look at the ancient genomes no one has lactose tolerance until recently, the past few thousand years.” For a genetic trait to become widespread that quickly, there should be a very important reason why people who have it survive and reproduce, while others die off.

Richard Evershed and colleagues mapped human milk use during the past 9,000 years, creating an enormous database from 6,899 animal fat residues derived from 13,181 fragments of pottery from 554 archaeological sites around Europe. Over the past three decades scientists, with experts like Evershed at the fore, have developed methods to analyze ancient pottery and reveal evidence of what it contained.

Evershed found plentiful evidence that humans were drinking milk widely, across Europe, from around 9,000 years ago.

George Davey Smith’s finding created another question for researchers; if lactose intolerant individuals can drink milk with no major ill effects, what drove the dramatic genetic shift that caused so many Europeans to quickly develop lactose tolerance?

Some factor or factors must have fast-forwarded the evolution of lactose tolerance, likely by making it critically important and even a matter of life and death.

Wilkin adds that scientists have been floating various ideas to explain the mysteries of milk digestion, including how lactose tolerance evolved so late and so quickly, and why heavy milk consumers like the steppe dwellers remain lactose intolerant. Now, she says, a framework exists that can further investigate those questions.

Full article at Smithsonian.

Note: This example of “rapid evolution” appears to only be adaptation based on pre-existing variations in the human genome (in order to favor survival), not the production of novel genetic information based on random processes of any kind. As such, might it not serve as additional evidence of intelligent design?

6 Replies to “Smithsonian Magazine: Why Did Europeans Evolve Into Becoming Lactose Tolerant?

  1. 1
    asauber says:

    “Comparison of model likelihoods”

    Yawn. We evidently know less than we did before.


  2. 2
    jerry says:

    Using the word “evolution” is a misnomer. It’s a small genetic change, nothing more.

    My guess this small change to the genome spread throughout the population because it had some advantages. Thank God, or else no pie ala mode.

    Apparently white skin in northern climes helped with Vitamin D absorption too. Natural selection working in genetics.

  3. 3
    asauber says:

    “Using the word “evolution” is a misnomer.”

    Speculate, throw the word Evolution around, “rewrite the textbooks”… what a joke.


  4. 4
    martin_r says:

    no evolution, just pre-designed adaptation …

    the same happened with Africans – INDEPENDENTLY from Europeans (Darwinian code word: convergent evolution)

    January 2007, an international team of researchers led by geneticist Sarah Tishkoff announced that they had uncovered the genetic roots of Africans’ lactose tolerance. Just as in Europe, on this continent, mutations (in this case, probably three) randomly arose, and these happened to have the effect of keeping the lactase gene switched on.


    of course, it wasn’t randomly, like the article states … but as we know, Darwinists believe in miracles, so let’s give it to them, that it happened ‘randomly’ on both continents :))))))

  5. 5
    bornagain77 says:

    As to Martin_r’s reference, lactase persistence ‘serendipitously’ originated independently (at least) four different times in a quote-unquote “marked example of convergent evolution”

    Convergent Adaptation of Human Lactase Persistence in Africa and Europe – January 2007
    Abstract: A SNP in the gene encoding lactase (LCT) (C/T-13910) is associated with the ability to digest milk as adults (lactase persistence) in Europeans, but the genetic basis of lactase persistence in Africans was previously unknown. We conducted a genotype-phenotype association study in 470 Tanzanians, Kenyans and Sudanese and identified three SNPs (G/C-14010, T/G-13915 and C/G-13907) that are associated with lactase persistence and that have derived alleles that significantly enhance transcription from the LCT promoter in vitro. These SNPs originated on different haplotype backgrounds from the European C/T-13910 SNP and from each other. Genotyping across a 3-Mb region demonstrated haplotype homozygosity extending >2.0 Mb on chromosomes carrying C-14010, consistent with a selective sweep over the past approximately 7,000 years. These data provide a marked example of convergent evolution due to strong selective pressure resulting from shared cultural traits-animal domestication and adult milk consumption.

    In short, evidence does not support the evolutionary hypothesis of lactase persistence in human adults as a consequence of selection. As Juan Brines noted, “A founder effect could be a more suitable explanation to justify this trait, and this mechanism does not need the cooperation of natural selection.”

    Adult Lactose Tolerance Is Not an Advantageous Evolutionary Trait – Juan Brines – 2007
    Excerpt: Some adult humans, unlike the remaining adult mammals, have the possibility to feed on milk (lactose tolerance, LT) based on lactase persistence (LP) in enterocytes. This condition has been observed mainly among populations originating in northwestern Europe, and in some ethnic groups around the Mediterranean and Near East, in Africa, and on the Indian subcontinent that have a long tradition of dairing, some 6000-9000 years.,,,
    To attain a genetic frequency of LT higher than 90%, as seen in some populations, a high mutation rate and a very high coefficient of selection are needed to displace non-carriers in as few as 200-300 generations. No differences, however, in viability and fecundity rates, the bases for natural selection, have been observed between lactose-tolerant and lactose-intolerant individuals. Moreover, fitness (the contribution of offspring to the next generation) is greater, by far, in lactose-intolerant populations; furthermore, demographic figures show, curiously, that the highest LT rates has been, generally, paralleled by the lowest demographic values, and vice versa.
    CONCLUSIONS.- A founder effect, without the cooperation of natural selection, could be a more suitable explanation to justify LT high rates in some populations.

    Moreover, “Mutations responsible for lactase persistence actually represent a loss of genetic information, a shut-down of normal regulation”, not a gain of genetic information.

    Got milk? Research finds evidence of dairy farming 7,000 years ago in Sahara – 2012?
    Excerpt: In premature babies, the gene coding for lactase is sometimes not yet active. And in much of the world’s population, the gene is downregulated after weaning, eventually producing some degree of lactose intolerance. Those whose genes are not downregulated are said to have “lactase persistence.” However, even lactose-intolerant people still have genes coding for lactase enzyme; they are just switched off.?In an adult with lactase persistence, one or both alleles of the lactase gene remain switched on.,,
    Mutations responsible for lactase persistence actually represent a loss of genetic information, a shut-down of normal regulation.

    Needless to say, mutations which “represent a loss of genetic information” is not the type of evidence that Darwinists need in order to provide empirical support for their theory.

  6. 6
    relatd says:

    At one time, the Smithsonian magazine was highly regarded. It cannot be any longer. I can no longer buy it.

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