New Human Species Discovered in Siberia: X-Woman

In a followup to an earlier post, researchers with the Max Planck Institute for Evolutionary Anthropology have made more than one extraordinary discovery this year.

Just before their recent triumph in sequencing a good bit of the Neandertal genome and producing the startling result that non-Africans have a little Neandertal DNA in them, word came that a Siberian hominid they’ve sequenced is a new species that lived about 30,000 to 48,000 years ago and was thus a contemporary of both modern humans and Neandertals.  And here’s another excellent article on the same topic.

A few years ago, the Neandertals were the only hominids known to be contemporary with Homo sapiens.  Coming on top of the surprising discovery in 2003 of Homo floresiensis, an extinct dwarf hominid or “hobbit” who once flourished upon the Indonesian island of Flores, the discovery of this new Siberian hominid means the list has grown to three in just a few years.  Undoubtedly paleoanthropologists are beginning to wonder what other surprises are in store.

The discovery was made by sequencing the mitochondrial DNA from a small finger bone found during excavations at Denisova Cave, located in the Altai Mountains of Southern Siberia.  The sex of the individual is still unclear, but in some quarters it is being called the “X-Woman.”

Since the Institute’s analysis shows that X-Woman shared a common ancestor with Homo sapiens and Neandertals about 1 million years ago, and this doesn’t coincide with known emigrations from Africa at about 1.9 million (Homo erectus), 500,000 (Homo heidelbergensis > Homo neanderthalensis) and 50,000 (Homo sapiens) years ago, it is therefore believed that the discovery of the X-Woman is evidence of yet another emigration ca. 1,000,000 years ago.

If you’d like to read books about human evolution owned by Greensboro Public Library, check out this previous post.

Italians 85% Sure They’ve Found Caravaggio’s Remains

In a brief followup to an an earlier post on the search for Caravaggio’s bones, MSNBC is reporting that the team which last year recovered remains thought to belong to the great artist has completed their analysis and announced they have a likely candidate — but they can’t be absolutely sure.  

‘There can’t be the scientific certainty because when one works on ancient DNA, it is degraded,’ Giorgio Gruppioni, an anthropologist on the team, told The Associated Press.  ‘But only in one set of bones did we find all the elements necessary for it to be Caravaggio’s — age, period in which he died, gender, height.’

Caravaggio (full-name Michelangelo Merisi da Caravaggio, (1571–1610), is considered to have been the last of the great Italian Renaissance artists.  His works, known especially for their dark chiaroscuro style, are credited with inspiring the Baroque period of the late 16th-18th centuries.  Others are intrigued by his troubled and tormented personal life, while some believe Caravaggio was the first truly modern painter.

2010, a Good Year for Neandertals

A few posts back, we wrote on the publication in Science of DNA evidence that Neandertals (or Neanderthals) interbred with modern humans and that non-Africans have a bit of Neandertal DNA in them.

This raised my curiosity about our cave-dwelling ancestors and led me to read a very interesting survey of the history of paleoanthropology (i.e., the study of ancient humans) called The Neandertals:  Changing the Image of Mankind by Erik Trinkaus and Pat Shipman.  These authors make it quite clear that there has been plenty of back-and-forth among scholars over the relationship between modern humans (Homo sapiens) and Homo neanderthalensis, dating back to the first discovery of a Neandertal skull cap and other bones in a cave in Germany’s Neander Valley in 1856.

For example, during the last couple of decades, and bolstered by DNA evidence, the so-called “out of Africa hypothesis” advocating total replacement of Neandertals by modern humans has gained sway.  But this theory is opposed by another theory called multiregionalism, which emphasizes continuity through gene flow, i.e., interbreeding.

The recent finding of DNA evidence that Neandertals interbred with sapiens indicates at minimum that total replacement is unfounded and that the “out of Africa” hypothesis will need some modification, since Neandertals are unknown outside Europe and Western and Central Asia.

But as I learned from Trinkhaus and Shipman, the originator of the “out of Africa” theory, a German named Günter Bräuer, argued as early as the 1970s, based upon his study of late archaic hominids in Africa,

that modern Homo sapiens had arisen initially in Africa and migrated outward to populate the rest of the world.  Humans . . . moved northward into Europe and westward across the continent, until they encountered and hybridized with Neandertals. . . .  Consequently, he [Bräuer] believed that Neandertals were not replaced entirely by modern humans, for they had left some genetic contribution to future generations.  [emphasis added]

Nearly four decades ago Bräuer thus seems to have anticipated a theoretical position that fits quite well with the recent finding of interbreeding made by the Max Planck Institute, as they map the Neandertal genome.

But this isn’t the only recent finding of great import about Neandertals.  Earlier this year, archaeologists working in Southeastern Spain led by João Zilhão published evidence that Neandertals used painted seashells decoratively and symbolically.  It had previously been believed that Neandertals adopted body ornamentation from Cro-Magnons (the first anatomically modern humans), who are believed to have begun having contact with Neandertals about 40,000 years ago, but Zilhão’s team found a paint-decorated shell dated to 50,000 years ago, as many as 10,000 years before Cro-Magnons would have arrived in Europe.  This suggests that Neandertals had a capability for symbolic thought that was not previously understood.

Zilhão also believes he now has dating evidence for “evolutionarily significant admixture” between Neandertals and modern humans, what is known as the “Ebro Frontier” model which suggests widespread interbreeding of the two in Iberia before Neandertals died out there about 37,000 years ago, based largely upon the anatomical features of a four year-old child (known as the Lapedo Child) unearthed at the Lagar Velho, Portugal, and estimated to be about 24,000 years old, which exhibits “a mosaic” of Neandertal and modern features.  Remains found at the Isreali sites of Skhul and Qafzeh in the 1930s are also believed to be anatomically modern humans with some Neandertal features.

So, one might say it has been a rather good year for Neandertals, as it seems they’re looking more human with just about each new discovery these days.

Nonetheless, as Trinkaus and Shipman describe in their book, we’ve been through this before.  In the early twentieth century, for example, most paleoanthropologists thought of Neandertals as another species entirely different from Homo sapiens.  By the 1960s, however, they had been rehabilitated and humanized as “the first flower children” by an archaeologist who studied Neandertal remains at an Iraqi site called Shanidar, only to once again be cast into otherness by the “out of Africa” hypothesis and its advocates, such as Chris Stringer, ca. 1990, supported by strong mitochondrial DNA evidence indicating a fairly recent African origin for modern humans — until of course the discovery of interbreeding with Neandertals published in May.

But no doubt the pendulum will swing back again.

At any rate, if you’d like to read more about human evolution, try some of the books from this previous post.

Famous Astronomer Nicholas Copernicus Reburied After Scientists Use DNA to ID Remains

In yet another neat DNA story, scientists have recently used the building blocks of life to help identify the remains of the famous Renaissance Polish mathematician and astronomer Nicolaus Copernicus (1473-1543), who, with his theory of the heliocentric or sun-centered universe, is often credited with starting the scientific revolution.

Alas, poor Copernicus died shortly after De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), his seminal work, was published.  During Galileo’s day, when findings with the telescope began to add weight to Copernicus’ ideas, On the Revolutions was deemed heretical by a then very conservative Roman Catholic Church.  

But with no little irony (at least in view of the Church’s later action against the work), Copernicus was buried on sacred ground beneath the floor of the cathedral of Frombork, located in Northern Poland.  Long since rehabilitated by the Church and honored for his landmark contributions to modern science, there had periodically been efforts to locate his remains there, but these had failed.  Furthermore, previous efforts to locate his tomb had made it clear that it would be difficult to distinguish Copernicus’ remains from many other anonymous burials. 

Nonetheless, in 2005 some bones were located which looked especially promising, since a facial reconstruction as well as the presence of some scars on the skull seemed to match up nicely with surviving contemporary portraits.  But the excavators still weren’t absolutely sure they had found the famous astronomer.

That’s where the DNA came in.  As it turned out, some volumes from Copernicus’ personal library, including the Magnum Romanum Calendarium (A Proposal for a Calendar Revision), had made their way to Uppsala University in Sweden — and this particular volume contained some human hairs from which DNA could be recovered.  (And as a librarian and long-time book collector, I can tell you from personal experience that lots of stuff can end up in books!)

Anyway, analysis established that some of the hair DNA matched the DNA from the remains recovered at Frombork and voilà:  proof that Copernicus’ remains had definitely been found.

And so it was that just a few days ago a man once branded as a heretic by the Roman Catholic Church was honorably reinterred               

If you’re interested, Greensboro Public Library has a number of books on Copernicus, including:  Copernicus by Jack Repcheck; The First Copernican:  Georg Joachim Rheticus and the Rise of the Copernican Revolution by Dennis Danielson; Uncentering the Earth:  Copernicus and the Revolutions of the Heavenly Spheres by William T. Vollmann; and On the Shoulders of Giants:  The Great Works of Physics and Astronomy, edited, with commentary, by Stephen Hawking. 

We’ve also got some juveniles such as Copernicus:  Founder of Modern Astronomy by Catherine M. Andronik and Nicolaus Copernicus:  The Earth is a Planet by Dennis Brindell Fradin.

Could DNA Analysis Help Solve Mystery of the “Lost Colony”?

I suppose just about everyone has heard of the famed “Lost Colony,” which was one of the first attempts by the English to settle the New World.

Located just off North Carolina’s coast on Roanoke Island, the story of the colony began in 1587 when the famous mariner Sir Walter Raleigh, who had received a charter from the Crown to establish a colony in North America, organized an expedition to be led by a friend of his named John White.  It is believed the colonists embarked for their future home in North America from Bideford, Devonshire, located on England’s southern coast.

The Roanoke Island settlers (perhaps 150 in number) got off to a good start, but by the end of the year they were running into trouble with Native Americans in the region, and White left for England to get help.  Delayed by war with Spain — 1588 was the year of the ill-fated Spanish Armada — White was unable to return until 1590, and when he at last did, he found the colonists had mysteriously vanished.  The only clue to their fate was the name of the tribe “Croatan,” carved near their abandoned fort.

To this day no one knows what happened to the colonists.  But one theory is that they were assimilated into one or more of the local Native American tribes.     

So, check out this neat story about how the current Mayor of Bideford, Devonshire, wants to try to use DNA analysis to link descendants of the colonists from his town, as well as elsewhere in England, with possible descendants in the United States.

If you’d like to read more about the Lost Colony, Greensboro Public Library may have some books for you.  Our more recent items include:  A Kingdom Strange:  The Brief and Tragic History of the Lost Colony of Roanoke by James Horn (this book was published just this year, by the way); A Voyage Long and Strange: Rediscovering the New World by Tony Horwitz; Roanoke:  Solving the Mystery of the Lost Colony by Lee Miller; and Lost Colony of Roanoke (History Channel video).

We also have lots of juveniles on this topic, and I’d be remiss if I didn’t mention the play on the legend of the Lost Colony by famous North Carolina playwright Paul Green, which of course is still performed at Manteo each summer and remains our state’s most popular outdoor drama.  Opening night is later this month, by the way.

A Neanderthal Eve?

For the last couple of decades the human evolution debate has been dominated by the “Out of Africa” theory, which holds that Homo sapiens evolved in Africa around 200,000 years ago, then began spreading to other continents at around 60,000 to 70,000 years ago.  This theory has developed from analysis of human DNA, i.e., from the study of our genetic makeup.   

The Out of Africa theory has been opposed by another called “multiregionalism,” which proposes that the much older ancestor of Homo sapiens, Homo erectus, as well as subsequent evolutionary developments such as Homo neanderthalensis, were all the same species, but had evolved gradually over about 2 million years and all over the world — albeit with some regional adaptations/differences — into Homo sapiens.  Rather than DNA, multiregionalists have relied upon fossil evidence, noting especially regional similarities between bones of erectus and later sapiens.  

Though multiregionalism still has its adherents — and the debate has often been filled with acrimony from both sides — the Out of Africa theory for the origins of modern humans has emerged as the dominant paradigm.  Thus, it has generally come to be believed that we all — regardless of ancestry, whether European, Asian, African, etc. — can trace our roots to an “African Eve” of comparatively recent origin.

One caveat in the debate which remained unresolved was whether or not Homo sapiens might have bred with Homo neanderthalensis, with whom they overlapped and had contact between about 100,000 and 30,000 years ago, when the last of the Neanderthals disappeared.  For, if modern humans and Neanderthals bred together — i.e., there was “gene flow” — then there is at least some basis for the multiregionalist position for gradual evolution as well as also the possibility of regional genetic differences in populations of modern Homo sapiens.

And evidence of gene flow is precisely what an extremely important study of Neanderthal DNA appearing in the current issue of the journal Science has found.  

To very briefly summarize, researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, using DNA samples from the bones of three Neanderthals found in Croatia, have recently succeeded in mapping a good bit of the Neanderthal genome (around 60%).  And when they compared Neanderthal DNA to that of a small group of modern humans with different ethnic backgrounds, they found a genetic contribution of Neanderthals to non-Africans (specifically Europeans, Asians and New Guineans) of 1-4%.

As you might expect this is a very controversial finding, because, as a New York Times report on the findings put it, it “would mean that non-Africans drew from a second gene pool not available to Africans.”   Though the Leipzig study does not exactly refute the Out of Africa theory, some modifications will at the very least be in order — as long as the findings hold up.

And for a person of European ancestry like myself, I suppose I’ll just have to get used to a “Neanderthal Eve” in my distant past, in addition to my African one.  Well, I’ve always kind of liked Neanderthals anyway.  So, that’s OK by me. 

If you’re interested in reading more on human origins, check out some titles from Greensboro Public Library listed in this previous post.

Majority of British Men Descend from Near East Neolithic Farmers, Recent Y Chromosome Study Finds

If you’re interested in human population genetics, check out this article about a Y chromosome study of British males which suggests most of them can trace their ancestry back to Neolithic farmers who began migrating in successive waves from the Middle East to Europe about 10,000 years ago (8,000 years BCE), finally arriving in the British Isles around 4,000 years BCE.

Also known as “the Neolithic Revolution,” the transformation of Europeans from hunter-gatherers to farmers is considered one of the great landmarks of Western history.  And its all the more remarkable that this great migration has left its mark upon the genes of modern day humans.

Of course, this new understanding is thanks to revolutionary advances in DNA research which have really only just manifested themselves during the last few decades.  Studies of matrilineal lines traced through mitochondrial DNA, as well as patrilineal y chromosome studies like the one noted above, are literally re-writing human prehistory.  Genetics has thus taken its place alongside archaeology, physical anthropology and linguistics as a key to reconstructing the human past before recorded history.   

If you’re interested in reading more on this new and important role for human population genetics, try some of these titles from Greensboro Public Library:  The Seven Daughters of Eve by Brian Sykes; The Real Eve:  Modern Man’s Journey Out of Africa by Stephen Oppenheimer; Genes, Peoples, and Languages by Luigi Luca Cavalli-Sforza; Relics of Eden:  The Powerful Evidence of Evolution in Human DNA by Daniel J. Fairbanks; The Real Eve (DVD); The 10,000 Year Explosion:  How Civilization Accelerated Human Evolution by Gregory Cochran and Henry Harpending; Jacob’s Legacy:  A Genetic View of Jewish History by David B. Goldstein; Abraham’s Children:  Race, Identity, and the DNA of “The Chosen People” by Jon Entine; Deep Ancestry:  Inside the Genographic Project by Spencer Wells; and Y:  The Descent of Men by Steve Jones.