A New Study Fails to Fix the Problem of Few Signs of Impressive "Positive Selection" in Humans

According to Darwinist dogma, lucky random mutations occur and cause "classic sweeps" or "classic selective sweeps" in which some new trait (offering a survival or reproduction advantage) becomes more and more common in the gene pool, eventually so common that most organisms in the population have that trait. The idea is illustrated in the visual below, which illustrates an example of the type of evolution called "positive selection" (which is a misleading term because "selection" means a choice by a conscious agent, and no actual selection is involved when so-called "positive selection" occurs).  The visual depicts a white-color trait offering a camouflage advantage, with the trait becoming more and more common over a timespan of many generations. 

The idea of "selective sweeps" can credibly explain very simple changes in a species such as a color change. But the idea of selective sweeps fails to explain the origin of components, capabilities and systems requiring a great organization of many parts. 

Claims about the power of "selective sweeps" (also called "classic sweeps") have mostly struck out at the plate, as more sensitive scans of the human genome have found little evidence of  such classic sweeps. A scientific paper was entitled "Classic Selective Sweeps Were Rare in Recent Human Evolution." By "recent human evolution" the paper meant the past 250,000 years.

Another scientific study in 2014 found there was virtually no sign of adaptive evolution in the human genome. The paper published in a mainstream science journal looked for traces of natural selection by looking for something called “fixed adaptive substitutions” in human DNA. The paper stated, “Our overall estimate of the fraction of fixed adaptive substitutions (α) in the human lineage is very low, approximately 0.2%, which is consistent with previous studies.”  It's rather hard to imagine a bigger fail or flop for Darwinian explanations. If such explanations were correct, we would have expected to find such signs of adaptive evolution in a large fraction of the human genome, not a fifth of one percent. 

In the 2018 book Who We Are and How We Got Here by David Reich, a professor of genetics at Harvard Medical School, the author makes this revealing confession on page 9: “The sad truth is that it is possible to count on the fingers of two hands the examples like FOXP2 of mutations that increased in frequency in human ancestors under the pressure of natural selection and whose functions we partly understand.” Judging from this statement, there are merely 10 or fewer cases where we know of some mutation that increased in the human population because of natural selection. The scientific paper “The Genomic Rate of Adaptive Evolution” tells us “there is little evidence of widespread adaptive evolution in our own species."

In the study here, an initial analysis found 154 positively selected genes in the human genome -- genes that seemed to show signs of being promoted by natural selection. But then the authors applied something they called "the Bonferroni correction" to get a more accurate number, and were left with only 2 genes in the human genome showing signs of positive selection (promotion by natural selection).  That's only 1 gene in 10,000. Call it the faintest whisper of a trace -- hardly something inspiring confidence in claims that we are mainly the product of natural selection. 

Recently some claimed this dismal situation has brightened, calling attention to a recently published paper entitled "Ancient DNA reveals pervasive directional selection across West Eurasia." An article on the Smithsonian site gives us lots of information about it. You can read the article here. 

Immediately the article tells us something that seems to confirm the "missing-in-action human adaptive evolution" story suggested at the beginning of this post. We read this:

"Previously, many scientists suspected that modern humans experienced relatively little evolution after arising in Africa around 300,000 years ago. They arrived at the idea by examining directional selection, a type of natural selection in which a specific variant of a gene, called an allele, provides an extreme version of a trait that is very beneficial to survival or reproduction. It continues getting passed to more offspring, and other forms of the gene appear less often in the population. Before the new study, only around 21 occurrences of directional selection had been identified."

Humans have more than 20,000 genes  The 21 occurrences referred to is a reference to only 21 genes. Such a picture of about "1 gene in a thousand" is a dismal picture for anyone wanting to claim evidence of adaptive evolution in humans. That is a "virtually no sign of adaptive evolution" type of picture. 

But the article then discusses that the new "Ancient DNA reveals pervasive directional selection across West Eurasia" paper claims to have detected more evidence of adaptive evolution in humans than the previously cited figure. We read the paper claims to have found "479 alleles that had been subjected to directional selection." 

But then the article gives us a reason for distrusting the new paper. We read this:

"However, 'the findings still require a leap of faith,' says Sasha Gusev, a geneticist at Harvard Medical School who was not involved in the work, to the Times. He is cautious about the vast natural selection the researchers say they’ve identified and takes issue with some of their statistical methods."

Also, the Smithsonian article fails to discuss any compelling examples of survival-improving adaptive evolution documented by the new study. The article headline has a mention of only trivial differences that do not improve human abilities or survival value. The headline is this:

Humans Are Still Evolving. Natural Selection Has Favored Genes Linked to Red Hair and Less Male-Pattern Baldness, a Study Suggests.

The article gives us only this listing of examples of human evolution claimed by the new paper: "Some of the alleles that natural selection has strongly favored are associated with traits including light skin tone, red hair, increased risk of celiac disease, lower chance of male-pattern baldness and lower risk of alcoholism." This does not seem to paint any picture conforming to ideas about natural selection as an explanation for the human race. Three of the five things mentioned are trivial and superficial things. One of the other things is something decreasing survival, and the other is one increasing survival (if we assume that alcoholic cavemen would be less likely to survive). We have no mention of any big important thing that fits in with some "this helps explain how you humans arose from ape-like ancestors" narrative. 

We read this: 

"Why were some alleles selected more often than others? 'My short answer is, I don’t know,'  Akbari tells the New York Times’ Carl Zimmer."

This sounds like odd little changes here and there, for reasons unknown, rather than any substantial confirmation of Darwinian claims about evolution being the cause of humanity.  And we don't even know whether the confusing story will stand up to scrutiny,  as the Harvard guy says the methodology is suspect.  

I looked at references to "positive selection" in the "Ancient DNA reveals pervasive directional selection across West Eurasia" paper.  The only specific references were these, none of which has any real relevance to explaining the origin of humans and their many unique mental powers:

• A claim of positive selection in some gene used by blood cells. 
• A claim of positive selection for some gene affecting tuberculosis risk. 
• A claim of positive selection for some gene affecting multiple sclerosis risk. 
• A claim of positive selection for some other gene relating to some iron buildup disease. 
• "Positive selection at an allele conferring immunity to HIV-1 infection."
• A claim of positive selection for some gene affecting cystic fibrosis risk. 
• A claim of "nominal evidence of positive selection" for something relating to years of schooling, although we should not take the claim seriously because "nominal" means "existing or being something in name or form only."

Figure 3 of the paper (shown below) gives us some reason for doubting the strength of the data and analysis in the paper. We have a figure showing lots of little line graphs supposedly showing "allele frequency trajectories." But each graph involves only 3 data items, meaning that claims of an increase or decrease in the alleles is not very solid. In general, line graphs plotting only 3 data points tend to be suspicious; but line graphs plotting 7 or 10 data points tend to be more reliable. 

So we seem to be left with no real evidence that there occurred selective sweeps or so-called "positive selection" that can explain the gigantic leap in intellectual function that mysteriously occurred around 50,000 years ago. We have some evidence for microevolution, but nothing that validates claims that Darwinian processes can produce macroevolution (dramatic evolutionary changes involving big leaps in functional capabilities). 

Regarding the study "Ancient DNA reveals pervasive directional selection across West Eurasia", evolutionary geneticist Arbel Harpak says, “The study is best viewed as offering amazing data and provocative hypotheses that will require much further scrutiny, rather than a settled account of recent adaptation in Eurasia."

The 3021 paper here is entitled "Two decades of suspect evidence for adaptive molecular evolution—negative selection confounding positive-selection signals." Using two species, the authors tested 100 genes that were identified by two of the main types of tests used to try to find genetic evidence of evolution.  They found " the >100 genes identified by the two tests do not overlap beyond random expectation."  This suggests that at least one of the tests was inaccurate, and also gives us reason for thinking that maybe both of the tests were inaccurate. 

No one should be too surprised about a lack of any genetic explanation for the origin of human minds (in the sense of some explanation involving so-called natural selection). In the 19th century the co-founder of the theory of natural selection (Alfred Russel Wallace) had very clearly explained why that  theory is incapable of explaining the wonders of human minds, in his essay here. That essay should be required reading in every class teaching the theory of evolution.

Biologists love to make unfounded boasts about the power of their explanations. But sometimes they are candid and tell us about how little their explanations work. For example, I recently discovered this quote by Cornell University evolutionary biologist Leslie S. Babonis: "The emergence of novel traits ─ traits that are unique to a group of organisms ─ is an important driver of organismal diversity, yet our understanding of how novel traits arise is still in its infancy." In the same year two biologists (James T. Stroud and William C. Ratcliff) confessed the lack of an evolutionary explanation for the original origin of multicellular organisms bigger than microbes. In a scientific paper they stated, "The evolution of multicellularity is among the most important transitions in the history of life, yet the processes that lead to it remain unresolved as all known transitions occurred more than 250 million years ago." Notice the "it was so long ago" excuse for the lack of an explanation, which sounds odd, given that similar guys have for so very long claimed to divine just what happened eons ago.  In a similar vein, a 2026 paper by several scientists confessed, "How animals evolved complex multicellularity from their unicellular ancestors remains unanswered."

Scientists tell us that the first three great leaps in the history of life were:

(1) The origin of prokaryotic cells (i.e. origin of life)

(2) The origin (eons later) of vastly more complex eukaryotic cells.

(3) The origin (eons later) of multicellularity (organisms with many cells arranged into an anatomy).

So-called natural selection and "selective sweeps" and "positive selection" fail to explain any of these things. The main scientist speculation about the origin of eukaryotic cells is not at all a Darwinian explanation.