Richard William Nelson
[Originally published in 2013 as Human Evolution Orthodoxy]
The genomic revolution is an increasingly challenging long-standing orthodoxy in human evolution, according to an international team of geneticists at the Max Planck Institute for Evolutionary Anthropology, as reported in the journal Nature.
The team, headed by Matthias Meyer of the Max Planck Institute for Evolutionary Anthropology, studied the mtDNA of 28 fossilized hominins estimated to be 400,000 years old from the Sima de Los Huesos cave in northern Spain‘s Sierra de Atapuerca Mountain range.
The team analyzed the genetics of these fossils that had been collected during the 1970s. The study report, entitled “A mitochondrial genome sequence of a hominin from Sima de Los Huesos,” unexpectedly concluded that the fossils were genetically similar to the Denisovans, even though they morphologically resembled Neanderthals.
Ancestry Models
Denisovans are of East Asian ancestry. Since the genetic evidence supports an out-of-Asia model while the morphological evidence supports an out-of-Africa model, human evolution orthodoxy faces a dilemma. In an interview with TIME science writer Per Liljas, Meyer explains:
The fact that they show a mitochondrial genome sequence similar to that of Denisovans is irritating. Our results suggest that the evolutionary history of Neanderthals and Denisovans may be very complicated.
Charles Darwin supported the out-of-Africa model of human evolution “by means of natural selection.” As anthropologist Richard Kline of Stanford University, in a 2009 editorial entitled “Darwin and the recent African origin of modern humans” published in PNAS, explains:
“The fossil record now confirms that Darwin and [Thomas] Huxley were right to place human origins in Africa.”
In 1856, the first Neanderthal fossil was unearthed in a German limestone quarry. Darwin considered the fossil of African ancestry in The Descent of Man:
It is therefore probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee; and as these two species are now man’s nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere.
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Darwin’s support of the out-of-Africa model, however, landed Darwin at odds with the more popular nineteenth-century out-of-Asia (Denisovan) model popularized by German embryologist Ernst Haeckel and British geologist William Dawkins.
By the mid-twentieth century, Darwin’s out-of-Africa model had gained widespread popularity, emerging as the orthodoxy of human evolution. The genomic revolution, however, is no respecter of subjective beliefs.
Model Critics
Science writer Jennifer Welsh, in an article titled “400,000-Year-Old Hominin DNA Throws Everything We Know About Human Evolution Into Disarray,” explains:
“Finding their DNA thousands of miles and hundreds of thousands of years away from where we thought Denisovans evolved throws everything we know about ancient humans and how they spread out around the globe and evolved into distinct species into question.”
Meyer agrees:
It’s extremely hard to make sense of. We still are a bit lost here.
In the National Geographic article “DNA From Ancient Site in Spain Reshapes Human Family Tree,” science manager Miguel Vilar looked for a new plan:
“Now, the story has changed, and we are scrambling to come up with a new narrative.”
A human fossil in Spain with East Asian genetics was a surprise.
Science writer Liz Fuller-Wright, interviewed Meyer for the article “Why scientists are baffled by a half-million-year-old human thigh bone,” subtitled “Scientists sequenced 400,000-year-old mitochondrial DNA, exploding the previous record for oldest DNA and introducing new questions into European and Asian history,” where he explains:
The fact that the mtDNA [mitochondrial DNA] of the Sima de Los Huesos hominin shares a common ancestor with Denisovan rather than Neanderthal mtDNAs is unexpected since its skeletal remains carry Neanderthal-derived features.
“This really raises more questions than it answers, really,” said senior author Svante Paabo, a biologist at the Max Planck Institute, in an interview with Monte Morin of the Los Angeles Times. “It’s a big surprise.”
Joseph Stromberg, writing for the Smithsonian Magazine, after reviewing available evidence, conceded:
“If this sounds like a complicated family tree to you, you’re not alone. This analysis, along with earlier work, adds further mystery to an already puzzling situation. Initial testing on the Denisovan finger bone found in Siberia, for instance, found that it shared mtDNA with modern humans living in New Guinea, but nowhere else. Meanwhile, it was previously thought that Neanderthals had settled in Europe and Denisovans further east, on the other side of the Ural Mountains. The new analysis complicates that idea.”
As early as 1982, Niles Eldredge of the American Museum of Natural History, recognized the problem with the once-popular human evolution orthodoxy, noting:
One could confidently expect that as more hominid fossils were found, the story of human evolution would become clearer. Whereas, if anything, the opposite has occurred.
Henry Gee, chief science writer for the journal Nature, regretting the increasing subjectivity of driving the science establishment in support of a theory, notes:
“To take a line of fossils and claim that they represent a lineage is not a scientific hypothesis that can be tested, but an assertion that carries the same validity as a bedtime story—amusing, perhaps even instructive, but not scientific.”
Darwin’s dilemma intensifies.
Genesis
Fossils offer the only direct evidence of natural history. Evidence from the fossil record, however, as well as the new genetic evidence from the northern Spanish cave, undermines the long-standing but now outdated. Paleontology, since the publication of The Origin of Species, has conveyed a long, hostile history against the theory of human evolution.
While increasingly challenging the theory of evolution, by contrast, the fossil record is compatible with the Genesis account written by Moses. In the words of Isaac Newton, an English mathematician, astronomer, and physicist is the world’s most influential scientist during the Scientific Revolution:
There is one God, the Father, ever-living, omnipresent, omniscient, almighty, the Maker of heaven and earth, the one Mediator between God and man, the man Christ Jesus.
Evidence of common ancestry and transitional links underscores why the theory of evolution remains speculative but not scientifically valid.
