Why did Neanderthals become extinct?

Why did Neanderthals become extinct?

Who were the Neanderthals? | DW Documentary

Oct 17, 2022

Long before Homo sapiens populated the earth, the Neanderthals lived in Eurasia. Now, paleoanthropologists in England and France are using new archeological methods to shed light on some previously unexplained Neanderthal mysteries.

In an age clouded by the mists of time, the first early humans colonized the Eurasian continent. They settled on land that had only recently been covered by glaciers. This species, called Neanderthals, died out about 30,000 years ago -- but at one time, they formed the largest group in an area that stretched from northern France to the Belgian coast and from the Channel Islands to southern England.

During the last Ice Age, the North Sea was frozen over -- and the English Channel was a small river that could easily be crossed on foot. The Neanderthals lived in close harmony with their perpetually changing environment. They had everything they needed to survive: the meat of prey animals, edible wild plants, water and wood for cooking and heating. How did these early humans develop over almost 300,000 years? What were their lives like before they became extinct?

Our documentary is based on the latest research. We investigate various populations of Neanderthals, and visit archaeological sites in northern France, southern England, and on the island of Jersey.

Renowned researchers such as the British paleoanthropologist Chris Stringer and his French colleague Ludovic Slimak describe how the Neanderthals lived, and discuss their cognitive abilities. Was this species capable of structured thinking? Did they have cultures, languages, and societies? How intelligent were they, and what sort of adaptive strategies kept them alive for 300,000 years? How similar were they to modern-day humans?

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Related Reference:

Neanderthal - From Wikipedia, the free encyclopedia

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Neanderthals 101 | National Geographic

Oct 13, 2017

Who were the Neanderthals? Do humans really share some of their DNA? Learn facts about Neanderthal man, the traits and tools of Homo neanderthalensis, and how the species fits into our evolution story.

Subscribe: http://bit.ly/NatGeoSubscribe

A Neanderthal Odyssey:

Everything We Know about the Neanderthals

NORTH 02  |  May 16, 2023  |  3:16:34

In this documentary, we discuss everything we know about the enigmatic Neanderthals. We dive deep into the latest scientific discoveries, archaeological findings, and genetic research to uncover the truths about Neanderthals. Through expert interviews, immersive visuals, and engaging storytelling, we shed light on their physical characteristics, intelligence, social structures, and cultural achievements.

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Human Evolution. How Does it Fit with the Recent Discovery of the genus, "Homo Naledi?"

Growing up as a conservative evangelical Christian I had been taught to consider the story of human evolution as spurious to the Word of God. Over the decades I have reconsidered all the arguments for special creation and against evolutionary creation and now deem my earlier education misdirected. That I may now rightly hold to progressive creationism (as opposed to immediate creationism) and consider it "divinely supernatural and special."

That the Creator God of the universe had supernaturally decreed creation's possibility using the operands of randomness and chaos and be ruled by the teleological principle of life as "always tilting towards biologic struggle and survival" regardless of the (toxic) eco-environments this struggle might occur within. As example, oxygen was a deadly toxin to evolutionary life at one time. As such, at all times the equation of "life" will be tilted towards the principles of creative "freedom" within a weak entropic system (which posits ultimate chaos) against a strong entropic system (which posits ultimate determinism) thus allowing for an evolutionary progression whereby the Sovereign Creator may have fellowship of a kind with His creation.

This then is the scientific teleology of evolution by the decree of its Creator God as proceeding from His very being and essence of love. A chaotic system always tilted towards life of some form. To the Christian, this teleology might take its ultimate form in a chaotic cosmic/natural system driving towards biotic enrichment, thriving biotas, and creative imagining. This may also be known as the Christian hope, which is a kind of theological eschatalogy coupled with Jesus' rule (I prefer the idea of divine participation) of love and goodwill with mankind and creation itself. Thus, evoloution's teleology can unfold toward the Christian hope of loving fellowship between, within, without, and everywhere about, all things (what the process theologian might know as panentheism's complex of driving relationships).

Once realizing this, I have lately, in recent years, worked towards describing how this progressive evolutionary creation may exist both on a doctrinal level as well as on a scientific one without going beyond the bounds of modern science (excepting, of course, that I write of it from a theologic and not an agnostic, or a/theistic, viewpoint).

And so, in today's posting, I wish to further explore the idea of human evolution through its taxonomical graphs and charts of recent discoveries of the 2.8 million year old homo naledi (star) species. A remarkable discovery found in an ancient graveyard deep underground by a nimble anthropological team of spelunking women who made this phenomenal discovery happen.

Question 1. Why is the chimpanzee closer to the homo genus than the gorilla? And where do orangutans fit in to this zoological chart?

The homo genus has been characterised exclusively as a genus of "bipedal apes" commonly known as "homo erectus" from which the word "humans" derive but differing from the chimpanzee (pan group) which half walks using both legs and all four limbs to travel. The larger family of apes from which humans have descended, such as the gorilla, or orangutan, primarily use all four limbs to travel while occassionally utilizing bi-pedal motion much less of the time than the chimpanzee genus.

Though all come from the superfamily of hominoidea - as can be seen from the taxonomical charts pictured above - as the species continued to evolve it became separated by zoological classifications from tree dwelling apes (gibbons), to partially tree-dwelling apes (orangutans), to ground/tree dwelling apes (gorillas), to ground/tree dwelling semi-bipedal apes (bonobos, chimpanzees), to exclusively ground dwelling bipedal apes (man).

The chart consequently shows how the chimpanzee genus is further removed from the gorilla genus and is more closely linked to the human genus. This is also supported by evolutionary genetic studies. As a result, the common chimpanzee and the bonobo (pygmy or dwarf chimp) of the genus Pan are the closest living evolutionary relatives to humans, sharing a common ancestry with humans from about four to seven million years ago."

At the perspective of a time-scale, this elapsed period of time also evidences the divergence of humans from chimpanzees. More specifically, the final separation of the Homo genus from the Pan genus is approxiamately 2.8 million years old thus showing us of the importance of the recent "Homo Naledi" cave discovery in August of 2015 in South Africa's Star Cave system.

What does this mean theologically?

In evolutionary terms it is pretty plain how human creation evolved from anthropological studies of the ape. And in theological terms, the passages in Genesis provide an ancient (Hebrew) tribal explanation to creation in non-evolutionary terms as this anthropology was unknown then. However, many well-meaning, Christians have attempted to show a 1:1 correlation between Genesis 1 with either progressive or immediate "theistic evolution" which would be an interpretive error both from a cultural standpoint as well as from a scientific one. At this time ancient man, such as the Semetic and Hebraic tribes, had no knowledge of either science or evolution. Moreover, the implication by theologians of insinuating human guidance by divine authorship supra-intending over a culture's era-specific ignorance is also a conjectural error to the surmise of textual formation.

The take away? Rather than getting hung up on a literal reading or correlation of the Genesis creation stories we may be confident that creation derives from a Creator who crafted an unusually complex method of creation by using all the ingredients of evolution to obtain the current results we are biologically familiar with. And that its testimony in Genesis is simply a literary account by the ancients using mythological description to describe this very same event in their own lay terms and knowledge of their day.

What does this mean? That God is neither denied nor mocked. That He is still Creator-Redeemer and shown to be intimately involved with His creation from whatever direction it came. Similarly, the bible is brought back down to reality, it is no longer made a mystical nor irrelevant collection of ancient manuscripts, and that we might rightly "divide / interpret" it more attuned or appropriately to its times and cultures. Which also means that this same Creator-Redeemer God then is active in our societies and cosmos today as much as He was beforetimes. We have lost nothing except our mistaken impulses to defend or mock our Creator. He needs no defense because He is. And any mockery but shows our deep shallowness to the everyday realities about us.

Too, we must now come to understand that evolution is always occurring - both in our present day as well as in the future beyond us. That it is a process which never stops. That underneath life itself is the continuing titanic struggle of biologic life to always exist despite the (toxic) eco-environments now present or occurring in the future.

This is the marvel of God's creation and the cosmic/biologic equation He has set in place so that at any present moment we, as homo sapiens (human beings), might have fellowship with our Creator-Redeemer, or any derivations of ourselves in ages future. But as humans, we cannot assume we are in exclusive communication with our Creator alone. Even the Psalmists and Prophets have written of the mountains and valleys, seas and skies, trees and fields, and all the living things on earth, as having a "form of communication" with its Creator. That it "delights" in His fellowship, "dances," "sings for joy," and "claps its hands" in response to His Almighty voice. Nay, we are not alone in our praise and dependence upon our Creator God who loves His creation and draws us toward Him into divine fellowship with one-and-all.

And though I do not encourage any form of "supernatural mystical communication" with the trees and mountains, birds and bees, still we find in the poetry and essays of human journals the deep realization that all things are connected and in communication with itself and its Creator God. What I might describe as a form of (process) panpsychism; but again, without getting all crazy and mystical about this observation. As we walk creation's fields and meadows, swim its streams and dive below its waters, we sense God's almighty hand of authorship in its templed majesties and shrouded veils of glory. The godfathers of ecology, John Muir, Henry David Thoreau, and Aldo Leopold, each in their own way reveled in this divine communion connecting humanity's existence even to the original American Indians who sensed the same in their animistic Spirit stories of creational connectedness and sacred fellowship.

Conclusion

To read Genesis then is to read it NOT in an evolutionary context but as (i) an ancient composition set within a paleo-creational understanding of a Creator-God named for His creational activity and perceived by the ancient's supernaturally curious wonder of life's many complex spheres of divine / human / creational interactions; (ii) that into creation's holy charters came creational indeterminacy and sentient freewill struggling between goodness and evil, order and disorder, each redefining the other in terms of fellowship and holiness; (iii) an immediate communion and fellowship with the Creator God and what it may mean for creation and mankind; (iv) that within this communion of struggle, of obedience, and willfulness, both creation and humanity came to be pitted against its God, each other, and themselves; (v) which is then described in terms of "life and death, light and darkness" within the hallowed altars of holy communion; (vi) that with death came the promise of God to be not only "Creator" but "Redeemer" - not only to mankind but to His holy creation as well; and finally, (vii) this holy redemption would come by grace and mercy, forgiveness and resurrection. This then is the fuller story of Genesis when read apart from its more popular classical or literal understanding rejecting evolution. It was what the ancients saw then of God's promise and what we need to see now in our dilemma between science, anthropology, and faith.

To this marvel of God's complex creation we may only bow our heads and utter, "Thank you O blessed Redeemer for your promise of life in the midst of death. Praise you for your wisdom and goodness and grace. For the majesty of your name and the councils of your justice when all things will be made new, and good, and holy, once more. Amen."

R.E. Slater

September 13, 2015
edited September 26, 2015; March 17, 2020

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Hominini

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Hominini

Not to be confused with Hominoidea, Hominidae, Homininae, or Hominina.

The Hominini is a tribe of the subfamily Homininae; it comprises three subtribes: Hominina, with its one genus Homo; Australopithecina, comprising several extinct genera (see taxobox); and Panina, with its one genus Pan, the chimpanzees (see the evolutionary tree below).[3][4] Members of the human clade, that is, the Hominini, including Homo and those species of theaustralopithecines that arose after the split from the chimpanzees, are called hominins; cf. Hominidae; terms "hominids" and hominins).

The subtribe Hominina is the "human" branch; that is, it contains the genus Homo exclusively. Researchers proposed the taxon Hominini on the basis that the least similar species of atrichotomy should be separated from the other two. The common chimpanzee and the bonobo of the genus Pan are the closest living evolutionary relatives to humans, sharing a common ancestor with humans about four to seven million years ago.[5] Research by Mary-Claire King in 1973 found 99% identical DNA between human beings and chimpanzees;[6] later research modified that finding to about 94% commonality, with some of the difference occurring in noncoding DNA.[7]

Sahelanthropus tchadensis is an extinct hominid species that lived 7 million years ago, very close to the time of the chimpanzee–human divergence. It is unclear whether or not it may be classed as hominin—that is, whether it rose after the split from the chimpanzees, or not.

A source of confusion in determining the exact age of the Pan–Homo split is evidence of a complex speciation process rather than a clean split between the two lineages. Different chromosomes appear to have split at different times, possibly over as much as a 4-million-year period, indicating a long and drawn out speciation process with large-scale hybridization events between the two emerging lineages as late as 6.3 to 5.4 million years ago according to Patterson et al. (2006).[8] The assumption of late hybridization was in particular based on the similarity of the X chromosome in humans and chimpanzees, suggesting a divergence as late as some 4 million years ago. This conclusion was rejected as unwarranted by Wakeley (2008), who suggested alternative explanations, including selection pressure on the X chromosome in the populations ancestral to the chimpanzee–human last common ancestor (CHLCA).[9]

All the extinct genera listed in the taxobox are ancestral to, or offshoots of, Homo. Few fossil specimens on the Pan side of the split have been found—the first discovery of a fossil chimpanzee was published in 2005;[10] it was from Kenya's East African Rift Valley and dated to between 545 thousand years, radiometric, (kyr) and 284 kyr (via argon–argon dating). However, both Orrorin and Sahelanthropus existed around the time of the split, and so may be ancestral to both Pan and Homo.

In the proposal of Mann and Weiss (1996),[11] the tribe Hominini includes Pan as well as Homo, but within separate subtribes. Homo and (by inference) all bipedal apes are referred to the subtribe Hominina, while Pan is assigned to the subtribe Panina. Wood (2010) discusses the different views of this taxonomy.[12]

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Lee R. Berger, a professor of human evolution studies at the University of

the Witwatersrand  in Johannesburg, unveiled a previously unidentified species

of the early human lineage — Homo naledi. By REUTERS on Publish Date

Homo Naledi, New Species in Human Lineage, Is Found in South African Cave

http://www.nytimes.com/2015/09/11/science/south-africa-fossils-new-species-human-ancestor-homo-naledi.html?_r=0

by John Noble Wildord

September 10, 2015

Acting on a tip from spelunkers two years ago, scientists in South Africadiscovered what the cavers had only dimly glimpsed through a crack in a limestone wall deep in the Rising Star Cave: lots and lots of old bones.

The remains covered the earthen floor beyond the narrow opening. This was, the scientists concluded, a large, dark chamber for the dead of a previously unidentified species of the early human lineage — Homo naledi.

The new hominin species was announced on Thursday by an international team of more than 60 scientists led by Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg. The species name, H. naledi, refers to the cave where the bones lay undisturbed for so long; “naledi” means “star” in the local Sesotho language.

In two papers published this week in the open-access journal eLife, the researchers said that the more than 1,550 fossil elements documenting the discovery constituted the largest sample for any hominin species in a single African site, and one of the largest anywhere in the world. Further, the scientists said, that sample is probably a small fraction of the fossils yet to be recovered from the chamber. So far the team has recovered parts of at least 15 individuals.

“With almost every bone in the body represented multiple times, Homo naledi is already practically the best-known fossil member of our lineage,” Dr. Berger said.

The finding, like so many others in science, was the result of pure luck followed by considerable effort.

Two local cavers, Rick Hunter and Steven Tucker, found the narrow entrance to the chamber, measuring no more than seven and a half inches wide. They were skinny enough to squeeze through, and in the light of their headlamps they saw the bones all around them. When they showed the fossil pictures to Pedro Boshoff, a caver who is also a geologist, he alerted Dr. Berger, who organized an investigation.

"Just getting into the chamber and bringing out samples proved to be a huge challenge.

The narrow opening was the only way in." - Lee Burger

Paul Dirks, a geologist at James Cook University in Australia, who was lead author of the journal paper describing the chamber, said the investigators first had a steep climb up a stone block called the Dragon’s Back and then a drop down to the entrance passage — all of this in the total absence of natural light.

For the two extended investigations of the chamber in 2013 and 2014, Dr. Berger rounded up the international team of scientists and then recruited six excavating scientists through notices on social media. One special requirement: They had to be slender enough to crawl through that crack in the wall.

One of the six, who were all women and were called “underground astronauts,” was Marina Elliott of Simon Fraser University in British Columbia. She said the collection and removal of the fossils involved “some of the most difficult and dangerous conditions ever encountered in the search for human origins.”

Photo by the New York Times

Besides introducing a new member of the prehuman family, the discovery suggests that some early hominins intentionally deposited bodies of their dead in a remote and largely inaccessible cave chamber, a behavior previously considered limited to modern humans. Some of the scientists referred to the practice as a ritualized treatment of their dead, but by “ritual” they said they meant a deliberate and repeated practice, not necessarily a kind of religious rite.

Pieces of a skeleton of Homo naledi, a newly discovered human species.

CreditJohn Hawks/University of Wisconsin-Madison, via European Pressphoto Agency

“It’s very, very fascinating,” said Ian Tattersall, an authority on human evolution at the American Museum of Natural History in New York, who was not involved in the research.

“No question there’s at least one new species here,” he added, “but there may be debate over the Homo designation, though the species is quite different from anything else we have seen.”

A colleague of Dr. Tattersall’s at the museum, Eric Delson, who is a professor at Lehman College of the City University of New York, was also impressed, saying, “Berger does it again!”

Dr. Delson was referring to Dr. Berger’s previous headline discovery, published in 2010, also involving cave deposits near Johannesburg. He found many fewer fossils that time, but enough to conclude that he was looking at a new species, which he named Australopithecus sediba. Geologists said the individuals lived 1.78 million to 1.95 million years ago, when australopithecines and early species of Homo were contemporaries.

Lee R. Berger, leader of a research team, in the Rising Star Cave near Johannesburg,

where over 1,550 fossil elements were found. CreditNaashon Zalk for The New York Times

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An expert all-women team of anthropologists dared the suffocating passages
of the South African Star Cave system. Kudos!

A Mighty Girl

https://www.facebook.com/amightygirl/photos/a.360833590619627.72897.316489315054055/901760099860304/?type=1&fref=nf&pnref=story

September 11, 2015

The discovery of a new hominin species is making headlines around the world this week but what many people don't realize is that the excavation team that uncovered this historic find was made up of six daring women scientists! The fossils were found at the bottom of a cave system in South Africa; one of the scientists, Marina Elliott, said that their collection and removal involved "some of the most difficult and dangerous conditions ever encountered in the search for human origins.” Thanks to the dedication of these six women, people everywhere will have the opportunity to gain new insight into the development of our species.

Palaeoanthropologist Lee Berger learned about the fossils in Rising Star Cave in October 2013 -- as well as their location, at the bottom of a 36 foot long shaft that gets as narrow as 7 inches across. He put up an ad on Facebook seeking scientists with a background in archaeology or paleontology, but with a catch: “the person must be skinny and preferably small. They must not be claustrophobic, they must be fit, they should have some caving experience, climbing experience would be a bonus.” He remembers thinking that “maybe there were three or four people in the world who would fit that criteria”, but within days he had 60 qualified applicants from around the world. He narrowed those down to six: Marina Elliott from Canada, Elen Feuerriegel from Australia, and K. Lindsay Eaves, Alia Gurtov, Hannah Morris, and Becca Peixotto from the United States.

Elliott, who was finishing a Ph.D. at Simon Fraser University when she saw the ad, was first on the scene. “I was predisposed to extreme environments,” she says. “Telling me that I’d have to do climbing, that it would be underground, and that it would be strange and potentially dangerous… it appealed.” Even still, she vividly recalls her first sight of the chute: “It’s a long crack, punctuated by shark-teeth protrusions. I remember looking down and thinking: I’m not sure I made the right decision." Given the difficulty and potential danger of the climb, Berger nicknamed the team “underground astronauts.”

During the 21-day excavation of the Rising Star cave, the team had to work carefully: “There was so much material and it was friable and delicate,” Elliott says. “And every day, we realized that we were pulling out another 40 or 60 fragments of this thing that was going to be incredible.” She and her five caving teammates excavated a nearly unheard of collection of hominin fossils: 1,550 fragments from at least 15 skeletons, representing a mix of male and female individuals. In the words of Ed Yong of The Atlantic, “To find one complete skeleton of a new hominin would be hitting the paleoanthropological jackpot. To find 15, and perhaps more, is like nuking the jackpot from orbit.”

Debate about Homo naledi’s age and importance in human prehistory, as well as the intriguing possibility that the bones are in the cave as a form of burial ritual, will be ongoing for years, but no one doubts that it represents an extraordinary find. Elliott has remained on the ground in South Africa where she is now directing the field operation and leading expeditions into other caves, eager to discover what else is out there. As she says, “We’re just scratching the surface."

You can read more about the all-female team of “underground astronauts” and this historic find on The Atlantic at http://theatln.tc/1Fzdsxh

To learn about more trailblazing women of science from around the world, we highly recommend the new book "Headstrong: 52 Women Who Changed Science -- And The World," for teen and adult readers, ages 13 and up, at http://www.amightygirl.com/headstrong-52-women

To introduce children to one of the world’s first paleontologists, Mary Anning, we recommend "Mary Anning and The Sea Dragon" for ages 5 to 8 (http://www.amightygirl.com/mary-anning-and-the-sea-dragon), “Stone Girl, Bone Girl” for ages 4 to 8 (http://www.amightygirl.com/stone-girl) and “The Fossil Girl” for ages 5 to 9 (http://www.amightygirl.com/the-fossil-girl)

For a wonderful book about six remarkable women whose curiosity about nature fueled a passion to steadfastly overcome obstacles to careers in traditionally men-only occupations, we recommend "Girls Who Looked Under Rocks: The Lives of Six Pioneering Naturalists" for ages 10 and up at http://www.amightygirl.com/girls-who-looked-under-rocks

If your kids would like to try an excavation of their own, check out the Crystal Mining Kit for ages 5 to 10 (http://www.amightygirl.com/crystal-mining-kit), the Treasures of the Earth Excavation Set for ages 5 to 9 (http://www.amightygirl.com/treasures-of-the-earth), and Smithsonian’s Diggin’ Up Dinos: T-Rex Kit for ages 7 to 12 (http://www.amightygirl.com/diggin-up-dinos-t-rex).

For more of our favorite science toys for igniting your children's curiosity about the natural world, visit our "Science Toys" section at http://www.amightygirl.com/toys/toys-games/science-math

And, if you have a Mighty Girl in your life who won't let any anyone tell her she can't do something because she's a girl, check out the "Though She Be But Little She Is Fierce" t-shirt -- available in a variety of styles and colors for all ages at http://www.amightygirl.com/fierce-t-shirt.

The Ancient Denisovans: Part of Man's Human Ancestry

National Geographic

http://ngm.nationalgeographic.com/2013/07/125-missing-human-ancestor/shreeve-text

July 2013

The Case of the Missing Ancestor

DNA from a cave in Russia adds a mysterious new member to the human family.

By Jamie Shreeve

Photograph by Robert Clark

In the Altay Mountains of southern Siberia, some 200 miles from where Russia touches Mongolia, China, and Kazakhstan, nestled under a rock face about 30 yards above a little river called the Anuy, there is a cave called Denisova. It has long attracted visitors. The name comes from that of a hermit, Denis, who is said to have lived there in the 18th century. Long before that, Neolithic and later Turkic pastoralists took shelter in the cave, gathering their herds around them to ride out the Siberian winters. Thanks to them, the archaeologists who work in Denisova today, surrounded by walls spattered with recent graffiti, had to dig through deep layers of goat dung to get to the deposits that interested them. But the cave’s main chamber has a high, arched ceiling with a hole near the top that directs shimmering shafts of sunlight into the interior, so that the space feels holy, like a church.

In the back of the cave is a small side chamber, and it was there that a young Russian archaeologist named Alexander Tsybankov was digging one day in July 2008, in deposits believed to be 30,000 to 50,000 years old, when he came upon a tiny piece of bone. It was hardly promising: a rough nubbin about the size and shape of a pebble you might shake out of your shoe. Later, after news of the place had spread, a paleoanthropologist I met at Denisova described the bone to me as the “most unspectacular fossil I’ve ever seen. It’s practically depressing.” Still, it was a bone. Tsybankov bagged it and put it in his pocket to show a paleontologist back at camp.

The bone preserved just enough anatomy for the paleontologist to identify it as a chip from a primate fingertip—specifically the part that faces the last joint in the pinkie. Since there is no evidence for primates other than humans in Siberia 30,000 to 50,000 years ago—no apes or monkeys—the fossil was presumably from some kind of human. Judging by the incompletely fused joint surface, the human in question had died young, perhaps as young as eight years old.

Anatoly Derevianko, leader of the Altay excavations and director of the Institute of Archaeology and Ethnography in Novosibirsk, thought the bone might belong to a member of our own species, Homo sapiens. Sophisticated artifacts that could only be the work of modern humans, including a beautiful bracelet of polished green stone, had previously been found in the same deposits. But DNA from a fossil found earlier in a nearby cave had proved to be Neanderthal, so it was possible this bone was Neanderthal as well.

Derevianko decided to cut the bone in two. He sent one half to a genetics laboratory in California; so far he has not heard from that half again. He slipped the other half into an envelope and had it hand-delivered to Svante Pääbo, an evolutionary geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. It was there that the case of the Denisovan pinkie bone took a startling turn.

Pääbo, a transplanted Swede, is arguably the world’s leading expert in ancient DNA, especially human DNA. His milestones are many. In 1984 he became the first person to isolate DNA from an Egyptian mummy. In 1997 he accomplished the same feat for the first time with a Neanderthal, a kind of human that vanished more than 25,000 years before the Egyptian pharaohs. That secured his scientific reputation.

When Pääbo received the package from Derevianko, his team was hard at work producing the first sequence of the entire Neanderthal genome—another feat that had once seemed impossible and that was occupying most of his attention. His lab also had a backlog of other fossils to test from all parts of the globe. So it wasn’t until late 2009 that the little Russian finger bone drew the attention of Johannes Krause, at the time a senior member of Pääbo’s team. (He’s now at the University of Tübingen.) Like everyone else, Krause assumed the bone was from an early modern human. He had developed a method for distinguishing the DNA of such a fossil from that of the archaeologists, museum workers, and anyone else who might have handled and therefore contaminated it.

Krause and his student Qiaomei Fu extracted the finger bone’s mitochondrial DNA (mtDNA), a small bit of the genome that living cells have hundreds of copies of and that is therefore easier to find in ancient bone. They compared the DNA sequence with those of living humans and Neanderthals. Then they repeated the analysis, because they couldn’t believe the results they’d gotten the first time around.

On a Friday afternoon, with Pääbo away at a meeting at Cold Spring Harbor Laboratory on Long Island, Krause called a meeting of the lab staff and challenged anyone to come up with a different explanation for what he was seeing. No one could. Then he dialed Pääbo’s cell. “Johannes asked me if I was sitting down,” Pääbo remembers. “I said I wasn’t, and he replied that I had better find a chair.”

Krause himself recalls that Friday as “scientifically the most exciting day of my life.” The tiny chip of a finger bone, it seemed, was not from a modern human at all. But it wasn’t from a Neanderthal either. It belonged to a new kind of human being, never before seen.

In July 2011, three years after Tsybankov unearthed the bone chip, Anatoly Derevianko organized a scientific symposium at the archaeological camp a few hundred yards from Denisova cave. At an opening night dinner punctuated with frequent toasts of vodka, Derevianko welcomed the 50 researchers, including Pääbo, who had come to see the cave and share their views on how the mysterious new human fit into the fossil and archaeological record for human evolution in Asia.

The year before, two other fossils had been found to contain DNA similar to that of the finger bone, both of them molars. The first tooth had turned up among the specimens from Denisova housed at Derevianko’s institute in Novosibirsk. It was bigger than either a modern human or a Neanderthal tooth, in size and shape resembling the teeth of much more primitive members of the genus Homo who lived in Africa millions of years ago. The second molar had been found in 2010 in the same cave chamber that had yielded the finger bone—indeed, near the bottom of the same 30,000-to-50,000-year-old deposits, called Layer 11.

Remarkably, that tooth was even bigger than the first, with a chewing surface twice that of a typical human molar. It was so large that Max Planck paleoanthropologist Bence Viola mistook it for a cave bear tooth. Only when its DNA was tested was it confirmed to be human—specifically, Denisovan, as the scientists had taken to calling the new ancestors. “It shows you how weird these guys are,” Viola told me at the symposium. “At least their teeth are just very strange.”

Pääbo’s team could extract only a tiny amount of DNA from the teeth—just enough to prove they came from the same population as the finger, though not from the same individual. But the finger bone had been spectacularly generous.

DNA degrades over time, so usually very little remains in a bone tens of thousands of years old. Moreover, the DNA from the bone itself—called endogenous DNA—is typically just a tiny fraction of the total DNA in a specimen, most of which comes from soil bacteria and other contaminants. None of the Neanderthal fossils Pääbo and his colleagues had ever tested contained even 5 percent endogenous DNA, and most had less than one percent. To their amazement, the DNA in the finger bone was some 70 percent endogenous. Apparently, the cold cave had preserved it well.

Given so much DNA, the scientists easily ascertained that there was no sign of a male Y chromosome in the specimen. The fingertip had belonged to a little girl who had died in or near Denisova cave tens of thousands of years before. The scientists had no idea, at first, what she looked like—just that she was radically different from anything else they had ever seen.

For a while they thought they might have her toe too. In the summer of 2010 a human toe bone had emerged, along with the enormous tooth, from Layer 11. In Leipzig a graduate student named Susanna Sawyer analyzed its DNA. At the symposium in 2011 she presented her results for the first time. To everyone’s shock, the toe bone had turned out to be Neanderthal, deepening the mystery of the place.

The green stone bracelet found earlier in Layer 11 had almost surely been made by modern humans. The toe bone was Neanderthal. And the finger bone was something else entirely. One cave, three kinds of human being. “Denisova is magical,” said Pääbo. “It’s the one spot on Earth that we know of where Neanderthals, Denisovans, and modern humans all lived.” All week, during breaks in the conference, he kept returning alone to the cave. It was as if he thought he might find clues by standing where the little girl may have stood and touching the cool stone walls she too may have touched.

Pääbo grew up in Stockholm with his single mother, a chemist, and on certain days with his father, a biochemist named Sune Bergström, who had another, legitimate family and would later win a Nobel Prize. Pääbo’s own first passion was Egyptology, but he switched to molecular biology, then fused the two interests in 1984 with his work on mummy DNA. Once anchored in the study of the past, he never let go. He is 58 now, tall and lanky, with large ears, a long, narrow head, and pronounced eyebrows that arch up and down animatedly when he’s excited—about Denisova, for instance.

How had all three kinds of human ended up there? How were Neanderthals and Denisovans related to each other and to the sole kind of human that inhabits the planet today? Did their ancestors have sex with ours? Pääbo had a history with that kind of question.

The Neanderthal DNA he had made headlines with in 1997 was utterly different from that of any person now alive on Earth. It seemed to suggest that Neanderthals had been a separate species from us that had gone extinct—suspiciously soon after our ancestors first migrated out of Africa into the Neanderthals’ range in western Asia and Europe. But that DNA, like Krause’s first extract from the Denisovan finger, was mtDNA: It came from the mitochondria, the energy-producing organelles inside the cell, and not from the cell nucleus, where the vast bulk of our genome resides. Mitochondrial DNA includes only 37 genes, and it’s inherited only from the mother. It’s a limited record of a population’s history, like a single page torn from a book.

By the time of the Denisova symposium, Pääbo and his colleagues had published first drafts of the entire Neanderthal and Denisovan genomes. Reading so many more pages allowed Pääbo and his colleagues, including David Reich at Harvard University and Montgomery Slatkin at the University of California, Berkeley, to discover that human genomes today actually contain a small but significant amount of Neanderthal code—on average about 2.5 percent. The Neanderthals still may have been swept into extinction by the strange, high-browed new people who followed them out of Africa, but not before some commingling that left a little Neanderthal in most of us, 50,000 years later. Only one group of modern humans escaped that influence: Africans, because the commingling happened outside that continent.

Although the Denisovans’ genome showed that they were more closely related to the Neanderthals, they too had left their mark on us. But the geographic pattern of that legacy was odd. When the researchers compared the Denisovan genome with those of various modern human populations, they found no trace of it in Russia or nearby China, or anywhere else, for that matter—except in the genomes of New Guineans, other people from islands in Melanesia, and Australian Aborigines. On average their genomes are about 5 percent Denisovan. Negritos in the Philippines have as much as 2.5 percent.

Putting all the data together, Pääbo and his colleagues came up with a scenario to explain what might have occurred. Sometime before 500,000 years ago, probably in Africa, the ancestors of modern humans split off from the lineage that would give rise to Neanderthals and Denisovans. (The most likely progenitor of all three types was a species called Homo heidelbergensis.) While our ancestors stayed in Africa, the common ancestor of Neanderthals and Denisovans migrated out. Those two lineages later diverged, with the Neanderthals initially moving west into Europe and the Denisovans spreading east, perhaps eventually populating large parts of the Asian continent.

Later still, when modern humans ventured out of Africa themselves, they encountered Neanderthals in the Middle East and Central Asia, and to a limited extent interbred with them. According to evidence presented by David Reich at the Denisova symposium, this mixing most likely occurred between 67,000 and 46,000 years ago. One population of modern humans then continued east into Southeast Asia, where, sometime around 40,000 years ago, they encountered Denisovans. The moderns interbred with them as well and then moved into Australasia, carrying Denisovan DNA.

This scenario might explain why the only evidence so far that the Denisovans even existed is three fossils from a cave in Siberia and a 5 percent stake in the genomes of people living today thousands of miles to the southeast. But it left a lot of questions unanswered. If the Denisovans were so widespread, why was there no trace of them in the genomes of Han Chinese or of any other Asian people between Siberia and Melanesia? Why had they left no mark in the archaeological record—no distinctive tools, say? Who were they really? What did they look like? “Clearly we need much more work,” Pääbo acknowledged at the Denisova symposium.

The best of all possible developments would be to find Denisovan DNA in a skull or other fossil with distinctive morphological features, one that could serve as a Rosetta stone for reexamining the whole fossil record of Asia. There are some intriguing candidates, most from China, and three skulls in particular, dated between 250,000 and 100,000 years ago. Pääbo is working closely with scientists at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing and has set up a DNA testing lab there. Unfortunately DNA does not preserve well in warmer climates. To date, no other fossil has been identified as Denisovan by the only way Denisovans can be known: their DNA.

In 2012 Pääbo’s group published a new version of the finger bone’s genome—astonishingly, one that in accuracy and completeness rivals any living human’s genome that has been sequenced. The breakthrough came from a German postdoc in Pääbo’s lab named Matthias Meyer. DNA consists of two interlocking strands—the familiar double helix. Previous methods for retrieving DNA from fossil bone could read out sequences only when both strands were preserved. Meyer had developed a technique for recovering short, single-stranded fragments of DNA as well, greatly increasing the amount of raw material to work with. The method produced a version of the Denisovan girl’s genome so precise that the team could discriminate between genetic information inherited from her mother and that from her father. In effect, they now had two highly accurate Denisovan genomes, one from each parent. These in turn opened a window on the entire history of their population.

One immediate revelation was how little variation there was between the parents’ genomes—about a third as much as there is between any two living humans. The differences were sprinkled across the genomes, which ruled out inbreeding: If the girl’s parents had simply been closely related, they would have had huge chunks of exactly matched DNA. The pattern indicated instead that the Denisovan population represented by the fossil had never been large enough to have developed much genetic diversity. Worse, it seemed to have suffered a drastic decline sometime before 125,000 years ago—the little girl in the cave may have been among the last of her kind.

Meanwhile the ancestral population of modern humans was expanding. Myriad fossils, libraries full of books, and the DNA of seven billion people are available to document our subsequent population history. Pääbo’s team discovered a completely different one inside a single bone chip. The thought tickles him. “It’s incredibly cool that there is no one walking around today with a population history like that,” Pääbo told me, his eyebrows shooting up.

And yet the Denisovans also have something to say about our own kind. With virtually every letter of the Denisovan genetic code in hand, Pääbo and his colleagues were able to take aim at one of the profoundest mysteries: In our own genomes, what is it that makes us us? What defining changes in the genetic code took place after we separated from our most recent ancestor? Looking at the places where all living humans share a novel genetic signature but the Denisovan genome retains a primitive, more apelike pattern, the researchers came up with a surprisingly short list. Pääbo has called it the “genetic recipe for being a modern human.” The list includes just 25 changes that would alter the function of a particular protein.

Intriguingly, five of these proteins are known to affect brain function and development of the nervous system. Among them are two genes where mutations have been implicated in autism and another that’s involved in language and speech. Just what those genes actually do to make us think, act, or talk differently than Denisovans, or any other creature that has walked the Earth, remains to be seen. The lasting contribution of studying Denisovan DNA, Pääbo says, “will be in finding what is exclusively human.”

But what of the little girl herself? The tiny bit of bone that is all we ever had of her—or at least the half that went to Leipzig—is gone now. In pulling DNA from it, Johannes Krause and Qiaomei Fu eventually used it all up. The little girl has been reduced to a “library” of DNA fragments that can be exactly copied again and again forever. In the scientific paper discussing the history of her population, Pääbo and his colleagues did mention, almost in passing, a few facts about her that they had gleaned from that library: She probably had dark hair, dark eyes, and dark skin. It isn’t much, but at least it sketches in broad strokes what she looked like. Just so we know whom to thank.

Nat Geo: The Apostles, Part2

Continue from -
Nat Geo: The Apostles, Part 1

http://relevancy22.blogspot.com/2012/04/nat-geo-apostles.html

SPREADING THE GOSPEL

by National Geographic

http://ngm.nationalgeographic.com/2012/03/apostles/apostles-art-gallery

The Bible says Jesus named a dozen of his most devoted disciples Apostles, or messengers, choosing a number that paid homage to the 12 tribes of Israel. The 12 Jews preached their new faith across thousands of miles in the first century A.D., changing history. Several early converts—including Matthias, Mary Magdalene, Mark, and Luke—also became apostles. A vision transformed Saul, a persecutor of the early Christians, into Paul. His missionary journeys helped spread Christianity throughout the Mediterranean.

MARY MAGDALENE

Mary, from Magdala, followed Jesus after he cured her of “seven demons.” She stayed

near him during the Crucifixion and was the first to see him after his resurrection.

BY DOMENICHINO, ARTE & IMMAGINI SRL/CORBIS

PETER

Jesus gave some disciples a second name; Simon the fisherman was also Peter, the “rock.”

He was the first to invite non-Jews to join the early church.

BY EL GRECO, ERICH LESSING, ART RESOURCE, NY

ANDREW

Persuaded by John the Baptist, Andrew and his brother Peter became Jesus’ first followers.

Andrew later preached in Greece and perhaps Ukraine.

BY EL GRECO, SCALA/ART RESOURCE, NY

JAMES THE GREATER

He was a fisherman with his brother, John, and was beheaded in Jerusalem. Some

believe that he preached in Spain and was buried there.

BY GAROFALO, FINSIEL/ALINARI/ART RESOURCE, NY

JOHN

John and his brother, James, “sons of Zebedee,” were in Jesus’ inner circle. The

fourth Gospel, three epistles, and the Book of Revelation are attributed to John.

BY VALENTIN DE BOULOGNE, RÉUNION DES MUSÉES NATIONAUX/ART RESOURCE, NY

PHILIP

Like nearly all of the Apostles, Philip hailed from Galilee, the region in northern Israel where

Jesus’ ministry was centered. He may have been martyred in Hierapolis.

BY POMPEO GIROLAMO BATONI, ILIFFE COLLECTION/ NATIONAL TRUST PHOTOGRAPHIC LIBRARY/JOHN HAMMOND/BRIDGEMAN ART LIBRARY

BARTHOLOMEW

Some believe he was Nathanael, who questioned the Messiah’s small-town origin: “Can

anything good come out of Nazareth?” He may have gone to Turkey, India, or Armenia.

BY REMBRANDT VAN RIJN, FRANCIS G. MAYER, CORBIS

THOMAS

Though doubting Thomas needed to touch Jesus’ wounds to be convinced of the

resurrection, he became a fervent missionary who is said to have proselytized in India.

BY EL GRECO, UNIVERSAL IMAGES GROUP/ ART RESOURCE, NY

MATTHEW

Jesus shocked Jewish society by dining with Levi, whose job as a tax collector had made

him an outcast. As an Apostle, Levi was called Matthew and wrote the first Gospel.

BY GUERCINO, HANS-PETER KLUT, BPK, BERLIN/ GEMÄLDEGALERIE ALTE MEISTER, STAATLICHE KUNSTSAMMLUNGEN DRESDEN/ART RESOURCE, NY

JAMES THE LESSER

The Bible reveals little about this James—only that he was a “son of Alphaeus.” Most

scholars think a different James wrote the biblical epistle of that name.

BY GEORGES DE LA TOUR, PHILIPP BERNARD, RÉUNION DES MUSÉES NATIONAUX/ART RESOURCE, NY

THADDAEUS

Several stories connect Thaddaeus, known also as Lebbaeus or Jude, to Persia. According

to Eastern tradition, he converted the city of Edessa after healing its king.

BY ANTHONY VAN DYCK, FRANCIS G. MAYER, CORBIS

SIMON

The Bible calls him Simon the Zealot, perhaps a reference to his political affiliation. Later

accounts depict him as a missionary to Persia, where he was martyred.

BY EL GRECO, ERICH LESSING, ART RESOURCE, NY

JUDAS ISCARIOT

Famous for betrayal, Judas (gold robe) was paid 30 pieces of silver for leading Roman soldiers

to Jesus in the Garden of Gethsemane. Judas later repented and hanged himself.

BY PHILIPPE DE CHAMPAIGNE, ERICH LESSING, ART RESOURCE, NY

MATTHIAS

To replace Judas Iscariot, the Apostles chose Matthias, who was a disciple during

Jesus’ ministry. Post biblical lore says he preached in the “land of the cannibals.”

BY ANTHONY VAN DYCK, ELKE ESTEL AND HANS-PETER KLUT, BPK, BERLIN/STAATLICHE KUNSTSAMMLUNGEN DRESDEN/ART RESOURCE, NY

MARK

Also called John, he was mentored by Peter—his likely source for writing the second Gospel -

and traveled with Paul to Antioch. Mark founded the Church of Alexandria.

BY VALENTIN DE BOULOGNE, DANIEL ARNAUDET AND JEAN SCHORMANS, RÉUNION DES MUSÉES NATIONAUX/ART RESOURCE, NY

LUKE

A gentile physician from Antioch who joined Paul’s missions, Luke chronicled the

development of the early church in the third Gospel and the Acts of the Apostles.

BY EDWARD MITCHELL BANNISTER, SMITHSONIAN AMERICAN ART MUSEUM, WASHINGTON, D.C./ART RESOURCE, NY

Paul