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[2011/12/19] Human Variability Can Be Rapid
Human Variability Can Be Rapid
Posted on December 19, 2011

All living humans are interfertile – one species by definition.  People from all parts of the globe can marry and have children, even though global travel is relatively recent in human history.  Yet we know there is considerable variability between tribes and nationalities.  Does this variability take millions of years?  Does it lead to the origin of new human species?  Recent evidence shows that variations can be rapid, both genetic and acquired, without reducing interfertility.

Jawboning about wisdom teeth:  A new study is something to chew on: diet, not evolution, may influenced human jawbone shape.  Nature (1 Dec 2011) mentioned a paper in PNAS (http://dx.doi.org/10.1073/pnas.1113050108) about how jaw shape appears to be systematically different between hunter-gatherers and agriculturalists.  Hunters have bigger jaws with more room for teeth, apparently due to the exercise of chewing.  According to the abstract, the finding explains “why there is often a mismatch between the size of the lower face and the dentition, which, in turn, leads to increased prevalence of dental crowding and malocclusions in modern postindustrial populations.”  Nature commented, using evolutionary dating assumptions, that “Agriculture and animal farming began emerging around 10,000 years ago in various regions of the world. As populations turned to farming, a diet of softer, more processed foods may have spurred the evolution of daintier jaws.”  It’s not really evolution, though, if there has not been the origin of a new species – it’s just variation.  Or, it might be an acquired characteristic.  Experiment: feed your youngster mammoth meat for 20 years, and see if he or she stays free of wisdom tooth problems.

Rapid head shape evolution:  The Xavánte Indians of Brazil have a characteristic head shape that differs from neighboring tribes.  The conclusion of a paper in PNAS (http://doi: 10.1073/pnas.1118967109) is that cultural traditions led to the “evolution” of this trait.  Live Science said, “Culture may trigger rapid evolution of various human features, suggests new research into the marital practices of a tribe from the Brazilian rainforest.”  Once again, though, this is not evolution, since the Indians are still Homo sapiens.  The abstract indicates that the authors were startled by their own conclusions, which logically could be extended to all “racial” differences around the world:

We found that the Xavánte experienced a remarkable pace of evolution: the rate of morphological change is far greater than expected for its time of split from their sister group, the Kayapó, which occurred around 1,500 y ago. We also suggest that this rapid differentiation was possible because of strong social-organization differences. Our results demonstrate how human groups deriving from a recent common ancestor can experience variable paces of phenotypic divergence, probably as a response to different cultural or social determinants.

Racial integration:  PhysOrg reported a new “headache” for paleoanthropologists.  Contrary to previous assumptions that parts of a skull would evolve independently from others, “We found that genetic variation in the skull is highly integrated, so if selection were to favour a shape change in a particular part of the skull, there would be a response involving changes throughout the skull,” said Dr Chris Klingenberg [U of Machester].  “This means that, in evolutionary history, any of the changes may have facilitated the evolution of the others.” What does this do to evolutionary assumptions about early man?  Dr Neus Martínez-Abadías [U of Barcelona] explained, “This study has important implications for inferences on human evolution and suggests the need for a reinterpretation of the evolutionary scenarios of the skull in modern humans.”  Since the study was done on skulls from the Middle Ages, variations they measured involved rapid, recent changes.

Neander-flaws:  There seems to still be tension among paleoanthropologists about what to do with Neanderthal Man.  The evolution worldview tempts them to keep them separate and distinct from us, but new discoveries continue to challenge the old interpretation.  Charles Choi in Live Science tried to maintain the separation: “Bulging Brain Structures Separate Us from Neanderthals.” He reported on work by Marcus Bastir of Spain, who did a sort of interior phrenology showing differences in skull patterns between them and us.  But Choi and Bastir had to admit further down in the article:

All in all, it remains unclear exactly how these brain differences might have set us apart from Neanderthals, Bastir cautioned. We only know how these skulls molded themselves around these brains, and not the precise structures of the brains in question.

Meanwhile, PhysOrg reported the discovery of a Neanderthal home in the Ukraine, with a frame made out of mammoth tusks, suggesting that Neanderthal “cave men” were well equipped brain-wise to plan and construct their own shelters:

Up till recently, most researchers studying Neanderthals had assumed they were simple wanderers, hiding out in caves when the weather got bad. Now however, the discovery of the underpinnings of a house built by a group of Neanderthals, some 44,000 years ago, turns that thinking on its head.

The discovery “tends to reverse decades of thinking,” the article continued.  “Instead of a clumsy, dim-witted people, it appears Neanderthals were more advanced than most had thought.”  Another surprise came to the news (PhysOrg): evidence of plant bedding 77,000 years old (in the evolutionary timeline), 33,000 years earlier than the Neanderthal house in the Ukraine, and 50,000 years earlier than the previously-known earliest evidence of bed-making.  The bedding could have been used for both sleeping and working, the article said.  Not only that, the researchers at the South African rock shelter found evidence of herbal medicines, hearths, and maintenance work to keep them clean – all indicators that the “modern humans” who inhabited the site exercised intelligence, planning and foresight in their daily activities.

These discoveries undermine Bastir’s phrenology.  Combined with the previously-mentioned articles, it could well be that the distinctive morphological traits of Neanderthals and other “archaic humans” represent natural variation within one human species.  (For more on Neanderthals as fully-human brethren, lookup “Neanderthal” in the search bar.)

Fire man:  Speaking of Africa, a new paper in PNAS today (http://doi: 10.1073/pnas.1118648109) concluded that humans have been using fire to manipulate the landscape for 40,000 years (using evolutionary dating), suggesting that they “learned to light fires in the dry season and to transform the landscape through grazing and cultivation.”  Interestingly, their evidence indicates “substantial human impacts on burned area would only have started ∼4,000 B.P. in open landscapes,” whereas “they could have altered fire regimes in closed/dissected landscapes by ∼40,000 B.P.” – i.e., the older dates are conjectural.  It would be difficult to reconcile grazing and cultivation starting 40,000 years ago with Nature’s statement (above) that “Agriculture and animal farming began emerging around 10,000 years ago….”  Would not fully-equipped humans with that kind of planning and foresight ability have invented civilization far earlier, considering also they were using herbal medicines 77,000 years ago according to the previous article?

Paleoanthropology, a theory in crisis:  Evolutionists seem to be waking up to the fact that these discoveries, and evidence of interbreeding between Neanderthals and Denisovans, are startling – unexpected, unpredicted, and difficult to explain.  In a new paper in Current Biology (Volume 21, Issue 24, R1002-R1009, 20 December 2011), Lalueza-Fox and Gilbert said as much:

Analyses of Neanderthal and Denisovan nuclear and mitochondrial genomes have revealed surprising insights into these archaic humans as well as our own species. The genomes provide a preliminary catalogue of derived amino acids that are specific to all extant modern humans, thus offering insights into the functional differences between the three lineages. In addition, the genomes provide evidence of gene flow between the three lineages after anatomically modern humans left Africa, drastically changing our view of human evolution.

Instead of “surprising insights,” they should have said “falsifications,” because none of that was believed by paleoanthropologists a decade ago.  That’s why it “drastically changed” their view.  They differentiated “archaic humans” from “our own species,” but then pointed to “evidence of gene flow” between all three groups.  You can’t get gene flow without sex.  If members of these groups produced children, they are all the same species according to the biological species concept (i.e., species are populations able to produce fertile offspring).

Their opening sentence reads, “Modern humans evolved from earlier species of Homo that originated in Africa around 2–2.5 million years ago subsequently migrating into Eurasia at different points in time.”  But try as they might to teach evolution and keep the ancestors separate, they had to acknowledge that “some argue” that Neanderthals, which they believe extend back 600,000 years, are not just a “human lineage,” but a “human species” (i.e., Homo sapiens).  Their own acknowledgement of interbreeding between Neanderthals and modern humans could suggest nothing otherwise, to say nothing of the additional evidence they reported about Neanderthal technology and art.  Furthermore, they admitted that the distinct bodily traits of the Neanderthals were most likely adaptations to climate and diet, as suggested in the first article above.

It seems, therefore, prematurely boastful for them to state, “Over the last 15 years, developments in ancient DNA techniques have revolutionised our understanding of recent hominin paleontology.”  A more accurate phrase might be, “has overturned our assumptions,” whatever “understanding” they thought they had before.  Throughout the paper, the authors retreated into uncertainties, debates, and controversies, but admitted in the last section, “The ancient hominin genomes of Neanderthals and Denisovans have demonstrated that conventional models of human evolution based on genetic analyses of modern data are over-simplified.”

Rapid genetic changes within species:  A non-human example shows that genomes within a single species can change very rapidly – not toward upward evolution, but toward degeneration.  PhysOrg put out an eye-catching headline, “Evolution at warp speed: Hatcheries change salmon genetics after a single generation.”  Since salmon farming began in recent years, the genes of the farmed salmon have degenerated from those in the wild.  The findings “show a speed of evolution and natural selection that surprised researchers.”  But looking for the promised evolution by natural selection in the article yields nothing to support survival of the fittest; quite the contrary, “What this study shows is that intense evolutionary pressures in the hatchery rapidly select for fish that excel there, at the expense of their reproductive success in the wild.”  This is no different from artificial selection with hogs and dogs.  Humans might select for traits they want, but could your poodle compete with wolves in Yellowstone?  Could Porky Pig compete with a wild boar?  It’s hard to call this the kind of evolution that would make Darwin smile:

When thousands of smolts are born in the artificial environment of a hatchery, those that survive best are the ones that can deal, for whatever reason, with hatchery conditions. But the same traits that help them in the hatchery backfire when they return to a wild river, where their ability to produce surviving offspring is much reduced.

Here was another falsification dressed up for the media as an evolutionary insight.  “To see these changes happen in a single generation was amazing,” Mark Christie (Oregon State U) said.  “Evolutionary change doesn’t always take thousands of years.”  This “extraordinarily fast” evolution begs numerous questions on the rates of genetic change over the presumed billions of years of life on earth – maybe even on the credibility of the evolutionary time scale.

Thrill of defeat:  In Live Science, Charles Choi summed up “What We Learned About Our Human Ancestors in 2011.”  Despite the upbeat tone about “key findings,” everything he listed amounts to a falsification of previously held beliefs.  He quotes Michael Hammer, who broke the news about gene flow between Neanderthals and Denisovans.  “Everywhere you look now, we find a little bit of interbreeding,” and that’s just after scratching the surface of genetic mixing between groups thought to represent different species.

One prediction can be made, though.  No matter the falsifying discovery, scientists and reporters will claim it “sheds new light” on evolution, as a BBC News story illustrated today (“fossils ‘shed new light’ on ocean community evolution”).  Readers will look in vain for any evolution. Instead, they will learn about a marine fossil bed that “resembles to some extent some of the modern communities found in the very deep sea,” despite being labeled Ordovician – 460 million years old.

We hope these stories will hammer home the sharp contrast between evolutionary bravado and empirical evidence.  Look at these.  Ponder.  Discriminate.  Analyze.  Think.  Where is the evidence that the diversity of plant, animal and human life has originated by an unguided process of natural selection?  Where have the evolutionary prognosticators gotten it right?  Learn to see past the triumphal boasts of the Darwin Party spin doctors, who twist falsifications into insights, and call their darkness “shedding light”.  Then ask which of these discoveries are better explained with the Biblical timeline and design world view (Answer: all of them).  Strip out the boasts, the spin, the promissory notes.  Look at the evidence itself.  Follow boldly where it leads.  It will lead to a rejection of the evolutionary story with its obligatory millions-of-years mythology, and it will “shed light” on creation – light that has been shining continuously, but has been shut out by closed eyes of the worldly wise.

Exercise:  Print out the Current Biology paper.  (1) Cross out every bald assertion of evolution, every “suggestion” that things “emerged,” every old-age date, and every triumphal claim.  (2) Purge your mind of evolutionary assumptions (i.e., long ages, progress through natural selection).  (3) Look at the remaining evidence and ask whether it fits better into evolution or creation.  If creation, ask if it fits better into the Biblical timeline or an old-age timeline.  If old-age, explain why Neanderthals sat in caves for 600,000 years without learning to ride a horse or build a city.  Visualize yourself as a Neanderthal (or Homo erectus for that matter) with a perfectly human brain, sitting by the hearth in a cold cave, bored to tears, saying, “Gee, why do we have to wait another 600,000 years for supermarkets?  Moe, let’s open a mammoth dog stand.  Here are some clams we can use for money.  Think of the possibilities!”

   [2011/12/24] Naturalizing Miracles, or Miracle-izing Nature?


   [2011/12/17] Philosophy on the Phringe


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