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Scientists analyzing the bones of the Australopithecus Afarensis skeleton known as ‘Lucy’ have suggested that she died from injuries sustained by falling from a tree. They say that fractures present on the bones of the skeleton are consistent with those that a human has when falling from a great height onto a hard surface.
“The consistency of the pattern of fractures with what we see in fall victims leads us to propose that it was a fall that was responsible for Lucy’s death,” John Kappelman, an anthropologist who led the study at the University of Texas in Austin told The Guardian. “I think the injuries were so severe that she probably died very rapidly after the fall.”
Reconstruction of Lucy’s fall. ( John Kappelman et al. )
According to the New York Times , Lucy’s skeleton underwent CT scanning and 3D models were made by “piecing together the virtual fragments to get a more accurate idea of their original shapes.” When Dr. Kappelman noticed a break in Lucy’s upper right arm, he found that it could have been caused by a compressive fracture (when a force pushes down on a bone and sometimes even forces it into another.)
Kappelman sought out advice from orthopedic surgeon Stephen Pearce, and a subsequent analysis of the skeleton suggested that there are cracks in more than a dozen of Lucy’s bones. Her skull, spine, ankles, shins, knees, and pelvis all showed signs of what the duo describe as compressive fractures from a fall.
Moreover, the scientists believe that an injury in the right shoulder is consistent with the type of fracture evident in people who instinctively put their arms out to try to save themselves during a fall. Kappelman said that the discovery is ““a unique signature” for a fall and evidence that the individual was conscious at the time.”
However, the combination of broken bones and probable organ damage from a fall of a considerable height suggested to Kappelman and his team that “death followed swiftly.” As Lucy only weighed less than 30kg (66.14 lbs.), the scientists believe that it would have taken a fall of about 15 meters (49ft.) for her to sustain the injuries.
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If Lucy did fall from a tree and die from her injuries, it adds an interesting perspective to the question of how much time Australopithecus Afarensis still spent in the trees versus their time on the ground. Some researchers believe that the flat feet of the species were better suited to terrestrial activities, while others see their hook-like hands and flexible shoulders as evidence of a large amount of time still spent in the trees. The findings of Homo Naledi remains have also been useful in the search for when bipedalism began to take hold in evolution.
A reconstruction of a female A. afarensis.
If A. afarensis climbed trees to nest or search for food, they could have spent hours at considerable heights every day. “We know that chimps fall out of trees and often it’s because they step on a branch that turns out to be rotten, and boom, down they come,” Kappelman told The Guardian. The fall from a tree is the best reason for the breaks, and a good explanation for how Lucy died, according to Dr. Kappelman :
“Based on clinical literature these are severe trauma events. We have not been able to come up with a reasonable way that these could be fractured postmortem with the bones lying on the surface or even if the dead body was being trampled on. If somebody is trampled on the bone breaks in a different way. It doesn’t break compressively.”
Perimortem fractures in Lucy’s postcranial skeleton as described by the recent research. ( John Kappelman et al .)
The article, which was published in the journal Nature, has been met with criticism by researchers who say that there are many postmortem causes that could explain the bone fractures. For example, Donald Johanson at Arizona State University, who discovered Lucy more than 40 years ago in the Afar region of Ethiopia, told The Guardian that “We don’t know how long the fossilisation process takes, but the enormous set of forces placed on the bones during the build up of sediments covering the bones is a significant factor in promoting damage and breakage.”
Tim White, a paleoanthropologist at the University of California in Berkeley, also said :
“Such defects created by natural geological forces of sediment pressure and mineral growth are very common in fossil assemblages. They often confuse clinicians and amateurs who imagine them to have happened around the time of death. Every single element of the Lucy fossil has cracks. The authors cherry pick the ones that they imagine to be evidence of a fall from a tree, leaving the others unexplained and unexamined.”
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Dr. Kappelman admits that although the hypothesis is one worth looking into, it is not undebatable: “None of us were there. We didn’t see Lucy die. Thinking about testing this idea, it’s hard to get someone to fall out of a tree, but we have tests going on every single day in every emergency room on planet Earth when people walk in with fractures from falls.”
On a final note, Kappelman and his team have been given permission by the Ethiopian government to make the bone data available online for scientists and schoolchildren to learn more about their research and Lucy. It also opens the door further for analysis and debate on Lucy’s life and death.
Cast of the remains of "Lucy". ( CC BY-SA 3.0 )
The website eLucy.org provides 3D renderings of the skeleton’s bones and allows interested individuals to download or print out casts of Lucy’s bones. Of the project, Dr. Kappelman has said “I’m happy that the 3-D files are out there. People can much more fully evaluate our hypothesis by looking at them, and it will be fun to see where it goes.”
8 Baffling Longtime Mysteries Solved
3.2-million-year-old Lucy, a prehistoric fossil star, tumbled to her death from high up in a tree after accidentally plunging to the ground while climbing or sleeping.
Breaks to her skeleton most likely occurred when she fell from a height of 13 meters or more, and she probably bled out pretty fast after falling, said paleoanthropologist John Kappelman of the University of Texas at Austin. Scientists have been at a loss to say how Lucy died since her 1974 discovery in Ethiopia. A team led by anthropologist Donald Johanson of Arizona State University in Tempe attributed Lucy's bone damage primarily to fossilization in a 1982 report.
Lucy The Australopithecine's Death: Skyfall Or Tall Tale?
The most famous human ancestor, Lucy the australopithecine, was named after the Beatles' Lucy in the Sky with Diamonds. But new research might warrant a theme song change to Adele's Skyfall. Did Lucy fall from a tree to her death three million years ago? Some palaeoanthropologists say yes, while others think it might be a tall tale.
Lucy's skeleton, one of the most complete hominin specimens ever found, was discovered in 1974 in the Afar region of Ethiopia. Small and bipedal, she is a member of the species Australopithecus afarensis. But her skeleton also preserves evidence of both ancestral and derived traits -- meaning that, while she walked on two feet, she also retained features that may have allowed her to climb trees efficiently.
Yesterday in Nature, University of Texas at Austin anthropologist John Kappelman and colleagues published research suggesting that fractures in Lucy's arms, legs and pelvis were the result of a fall from a large height, such as a tree. But other palaeoanthropologists have been quick to call this interpretation hasty and incomplete.
Kappelman and colleagues' article has been summarized well by Forbes contributor Brid-Aine Parnell and others. In short, using high-resolution CT scans, the team got tens of thousands of digital slices of Lucy's bones. Kappelman then noticed that fractures to the bones -- especially the upper arm bone at the shoulder -- were not consistent with taphonomic (post-mortem) damage caused by millions of years in the ground. Given the patterning of the fractures, Kappelman and colleagues suggest that Lucy fell out of a tree, hitting the ground feet-first and then attempted to break her fall with her arms. The severity of the injuries would have caused bleeding and organ damage that would have killed her shortly after.
3.2 million year-old fossil 'Lucy' is unveiled at Addis Ababa's National Museum on May 7, 2013. . [+] (Photo credit Jenny Vaughan/AFP/Getty Images)
It's a nice story, and, as far as I know, the first study to put a forensic anthropology spin on a hominin fossil. But it's also difficult to buy, particularly since even contemporary forensic anthropologists often have trouble identifying an exact cause of death from a modern skeleton. How can this be pushed back millions of years into the past, when soil pressure, carnivore activity, and other natural forces have compromised both the body and the death scene? I'm not an expert in either palaeopathology or forensic anthropology, though, so I've been reading with interest the reactions of those experts to this study.
Palaeoanthropologist John Hawks at the University of Wisconsin provides the most thorough critique of the paper on his blog. He has no trouble believing that a hominin who could both climb and walk would have fallen to her death, he writes, but he disagrees with Kappelman and colleagues' interpretation of the fracture patterning.
The Nature paper presents evidence from nearly two dozen bones of Lucy's skeleton, with the authors claiming that they are perimortem fractures, made around the time of death. "On the surface," Hawks writes, "it might seem like a watertight case. but if Lucy really had fractures on more than 75% of her preserved bones, she didn't fall out of a tree, she fell out of an airplane."
As an example of the problems with the methods used in the paper, Hawks points out the first rib. Kappelman and colleagues argue that a fracture of this rib represents extreme trauma to the shoulder. Hawks, though, notes that "there is another process that breaks first ribs very commonly in the fossil record: becoming a fossil. I am not aware of any first rib from a Plio-Pleistocene hominin that is intact."
Donald Johanson, the American scientist who discovered 3.2 million year-old fossil 'Lucy' is . [+] pictured at Addis Ababa's National Museum. (Photo credit Jenny Vaughan/AFP/Getty Images)
It's not just Hawks who is concerned about the over-interpretation of the fractures either other palaeoanthropologists are piling on the criticism. Don Johanson of Arizona State University, who discovered the specimen in the 1970s, has found no definitive proof for how she died. Zach Throckmorton of Lincoln Memorial University noted that "not a single comparative image from a modern clinical case of known history" was published in the new analysis. Tim White of the University of California at Berkeley told the AP that this new research is a "misdiagnosis" focusing on only the evidence that the researchers wanted to see. White went even further when he told ScienceNews that Kappelman and colleagues' study is "a classic example of paleoanthropological storytelling being used as clickbait for a commercial journal eager for media coverage."
White, Throckmorton, and Hawks all point out a clear failing of the paper: the failure to compare. Palaeoanthropology as a field is essentially built on comparisons, because that's how researchers piece together the human evolutionary tree and see changes and similarities over time. The Kappelman paper lacks comparisons -- especially to animal fossils that have similar fractures. "If the authors want anyone to believe their analysis of the Lucy skeleton," Hawks writes, "they need to demonstrate that the fractures on the Lucy skeleton are different from those present on other fossils."
The big problem with the Nature article, then, is not necessarily with the conclusions -- it makes fine sense that Lucy may have fallen out of a tree to her death -- or even with the methods, but rather with the cherry-picking of the data used to arrive at those conclusions. By publishing only the evidence that fits their interpretation, Kappelman and colleagues do not fully make their case for cause of death. This is problematic, since researchers who have published on the fracture patterns and who have considered the entire skeleton have found it consistent with post-mortem damage typical of other fossils.
Extraordinary claims require extraordinary evidence, as Carl Sagan used to say. Without solid comparative evidence for the injuries to Lucy's skeleton, Kappelman and colleagues may have given us something interesting to think about, but have not yet rewritten our understanding of hominin life between the trees and the ground.
Haile-Selassie said the skull has a combination of “primitive and derived cranial features” that were not expected to be on a single species.
The discovery gives scientists more insight into the ancestry of humans and evolution patterns.
“Until now, we had a big gap between the earliest-known human ancestors, which are about 6 million years old, and species like ‘Lucy’, which are two to three million years old. One of the most exciting aspects of this discovery is how it bridges the morphological space between these two groups,”, Melillo said in a statement.
The skull was found “in the sandy deposits of a delta where a river entered a lake,” making researchers eager to know more about the environment in which the species lived.
A. Anamensis’ skull was found just 34 miles north of where Lucy was discovered in 1974, CNN reports.
Still a Theory
Paleontology remains a competitive discipline even though its central mystery appears to have been solved. Agreement over dinosaur extinction is far from unanimous, and fossils continue to be found that add to the body of knowledge about how the dinosaurs lived and died. Only recently have birds been identified as descendants of the dinosaurs, and theories regarding dinosaur intelligence and behavior continue to change. Even long-established truths such as dinosaurs’ cold-bloodedness are open for debate. The climate change theory still holds sway over some scientists, who refute that the Chicxulub impact was the sole cause of the extinction. Evidence from the 65-million-year-old lava flows in India hint that a giant, gaseous volcanic plume might have initiated global climate change that threatened the dinosaurs. Scientists’ continued research will help paint a more detailed picture of the ever-changing, ever-evolving planet.
Battle of the Bones
Lucy is a 3.2-million-year-old fossil. Her three-and-a-half-foot-tall partial skeleton has been reconstructed to capture her in midstride, with long arms swinging loosely. She looks jaunty, relaxed, ready to take on all comers. And for good reason.
When an expedition from the Cleveland museum unearthed Lucy in Ethiopia in 1974, she became one of the most important scientific discoveries of the last century. Lucy was then the oldest and most complete human ancestor ever found. The day she died in an African pond became the furthest point back in time to which humankind could look for an explanation of its origins.
Lucy told us more about who we are and how we evolved than anyone ever had. For that she was christened the Mother of Humankind and became a bit of a pop-culture hero. Unlike most anthropological finds, Lucy wasn't destined to spend the rest of her days being discussed in arcane journals. She became the ambassador of modern evolutionary science, a skeletal celebrity who began showing up on T-shirts and tattoos. She catapulted her discoverer to worldwide prominence. And since a Cleveland team was responsible for the find, northern Ohio has basked in Lucy's reflected glory ever since.
During the past quarter-century, Lucy's star has barely dimmed, even though other ancestors have been discovered, some dating back 4.4 million years. She remains the flashpoint for debate on the origins of humankind and is still considered by many to be "the mother of us all."
But now, from across the planet in South Africa, an upstart Kansan is contesting Lucy's matriarchy. He believes his own discovery may not only dethrone Lucy, but prove that we've misunderstood our family tree all along. The brawl that's ensued is getting downright ugly, replete with accusations and counter-accusations, threats of litigation, and a brand of mudslinging one wouldn't expect from the seemingly decorous scientific world.
Most folks think of evolution as a valiant, purposeful progression, an orderly series of "improvements" that raised us up from the lowly chimp to the pinnacle of ultimate "Survivor" Richard Hatch.
Evolution is not a neat, orderly stair climb, but a random series of mutations and adaptations.
Here's what we seem to know: About 5 or 6 million years ago, one species of ape split in two directions. One lineage slowly and haphazardly adapted to fruit-filled rain forests and became chimpanzees. The other line slowly and haphazardly adapted to just about everywhere else and formed the many-branched family tree of hominids, or walking apes. From that tangled limb, we are the lucky survivors. With such a short separation, people and Bonzo share more genes in common than a horse and a zebra.
The closest human ancestors are called Homo erectus. About 1.8 million years ago, they began spreading from Africa to most of Europe and Asia. Their bodies were stronger versions of ours, though housing smaller brains. They were close enough, however, to spur vigorous debate over when and where this species turned into us.
As Darwin predicted, the oldest and most apelike of early human ancestors lived in Africa. Since the first fossil discovery there in 1924, the continent has yielded 12 to 16 species, depending upon who's doing the counting.
The biological definition of a species is a group of individuals that cannot breed with another species and produce fertile offspring. So naming species from fossils is a tricky business, coming down to the shape of jaws and teeth, the size of the cranium, the curve of a limb bone. Setting up some sort of genealogical relationship over millions of years is even trickier. But that doesn't stop people from trying.
From 1925 through 1973, Africa's rocks and caves revealed an enigmatic bunch. From the south, there was Australopithecus africanus, which lived from 2.8 million until 2.3 million years ago, and Australopithecus robustus, with huge molars and a crest along the skull to anchor powerful chewing muscles. They appeared 1.9 million years ago and disappeared a million years ago.
In eastern Africa, the finds included Australopithecus boisei, another chewing machine, and its contemporary Homo habilis, at 2.4 million years old a still-contested candidate for the first member of our own genus.
Here's where Lucy comes in.
In 1973, Don Johanson was a newly minted Ph.D., an anthropology instructor at Case Western Reserve University, and a curator at the Cleveland Museum of Natural History. He and a French team led a joint expedition to Hadar, Ethiopia, where Johanson found a complete knee joint, indicating an upright creature. The next year, he found Lucy. The third year, the team uncovered "the First Family," a group of at least 13 individuals who died together.
At the time, they were the oldest and most complete hominid remains ever found. Lucy's skeleton is 23 percent complete, which doesn't sound like much, but we're talking quality, not quantity. What was preserved, including leg, arm, and pelvic bones, provided the best picture yet of how these early ancestors moved. C. Owen Lovejoy of Kent State University was the first to look at the skeleton and the other bones, and he concluded that the creatures walked upright, as we do, instead of knuckle-walking, as apes do. Footprints in volcanic ash from the same time period confirm that this is so.
With the fossils on loan to Cleveland for five years from the Ethiopian government, Johanson joined forces with Tim White of the University of California at Berkeley. The latter, who had worked with the legendary Mary Leakey in Tanzania, showed Johanson that some fossil jawbones matched those from Ethiopia. In 1978 Johanson and White named the new species Australopithecus afarensis (after the Afar Triangle region). The creatures appeared 3.9 million years ago and enjoyed a 900,000-year run.
With the discovery carrying them that far back in time, the pair decided that perhaps they could finally bring some order to the jumble of species that had already been unearthed across Africa. It was an ambitious conclusion -- that Lucy and her family were a significant enough find that they could provide the cornerstone for reconstructing unknown centuries of human history.
Johanson and White eventually distilled and published their now famous theory that Lucy's people were our oldest known ancestors at the base of a Y-shaped family tree. One branch led to the two South African species that eventually fell to extinction. The other led to us.
Not only was Lucy a major find, she did a great deal for Cleveland. In the 26 years since her uncovering, the city baptized itself the birthplace of rock and roll. Though "Cleveland bones!" doesn't make for the best of marketing slogans, the region can reasonably argue that it has become one of America's premier centers for fossil study.
"The northern Ohio area in general has been known for lots of years as a key place for the study of human origins," says Berkeley's Tim White, among the superstars of fossil hunting.
The Museum of Natural History's Hamann-Todd Collection has 3,100 human skeletons and more than 900 African ape skulls and skeletons, and is the largest assemblage of its kind in the world. Some 200 scholars visit each year for medical and evolutionary research.
The museum and Kent State University together house the Midwest's largest collection of pre-human fossil replicas. Moreover, Kent's C. Owen Lovejoy and the museum's Bruce Latimer are regarded as top scholars in the field, routinely called in for their advice on new finds. Lovejoy's rumbling baritone has been heard on NOVA and BBC specials.
Today, Latimer is curator of physical anthropology at the museum, Johanson's old spot. He also directs the biological anthropology department in Case Western's medical school.
In his office is a chest-high safe with doors a half-foot thick. This is a sacred place, where the fossils of Lucy and the First Family once rested. When the five-year loan agreement expired, Johanson returned the bones to Ethiopia. What remains are replicas, painted down to the slight pink tinge in Lucy's molars, filling their slots in custom-cut foam cushions. Under even stricter lock and key are the first plaster casts made of the bones, in case the originals in Ethiopia somehow get lost or destroyed.
Lucy's still doing fine, thank you.
But you might not get that impression from Lee R. Berger, a young paleoanthropologist with a gift for self-promotion, breathless prose, and an extraordinary talent for uniting scientists who no longer speak to each other -- if only because they agree that Berger's a lightweight who puts politics before science.
Berger grew up in rural Georgia with a love of its ancient Native American sites. He moved to South Africa in 1989. At the University of the Witwatersrand, or Wits, he studied under the venerated Phillip V. Tobias. In short order, Berger discovered the country's first new cave to yield hominids in 44 years, and his flair for fund-raising and publicity attracted the National Geographic Society and other donors. Following Tobias's 1996 retirement, Berger was appointed the third director of paleoanthropological research in the school's history.
Whether on PBS or on the phone, he is engaging, often answering questions with a chuckle. He carries an infectious enthusiasm for Africa and his field his favorite word seems to be "vibrant."
"I have had the privilege of being in the midst of an emergent South Africa," he says from his home in Johannesburg. "There has been a refocus on the research here. It's been largely ignored."
Berger's thesis is that the South African branch of the Y-shaped tree -- the one that supposedly fell to extinction -- may well be the branch that led to today's people, and that his adopted home is the more likely launching pad of humankind. This means East Africa, and Cleveland's famous discovery, would be the dead end.
So Berger wrote a book, In the Footsteps of Eve. It arrived in June, along with a 10-city U.S. tour. It's not your standard weighty academic text. This is a brisk, entertaining read, a style that speaks to another of Berger's core missions: "I'm trying to bring a science that is often pulled away from people to people."
If the tone appears light, however, the message is anything but. In print, Berger aspires to a lofty purpose, revealed through grand phrases such as "force a revision of our understanding of human evolution."
What needs to be understood, Berger says, is that his adopted country could be the true cradle of humankind. "There is an undeniable and real focus on East African fossils," he says. "I'm not attacking my colleagues. I'm pointing out there's fantastic fossil evidence down here that needs to be included in a more vibrant way in our fossil interpretations. All I'm saying is, it's complex."
This seems innocuous enough. In fact, the only one who appears to believe an East Africa-South Africa rivalry exists is Berger.
But it's not his central thesis that's creating so much heat. It's the way he's gone about asserting it that other scientists find so irksome. As Berger grandly notes, his theory will "convince my colleagues around the world that they'd all been wrong in their understanding of early human evolution."
It goes like this: South Africa's A. africanus lived some 200,000 years after A. afarensis, Lucy's species. But Berger noticed africanus had slightly longer arms and really big shoulders, compared to its squat legs. At the same time, its brain was a bit bigger, and its teeth were more "modern."
Furthermore, there exist two broken, scrappy skeletons from a later period, when humankind started the crossover from an ape-man species to something more closely resembling today's people. The arms look pretty long, but it's hard to tell.
To those of us with a high-school level of scientific comprehension, such matters may seem better left to guys with microscopes. But Berger thinks his theory has dramatic implications for those who study these things. If we did evolve from the South African species, it throws off-kilter any previous understanding of our origins.
"Lucy may well have to relinquish her position as the mother of us all," Berger proclaims. Berger's not insisting this is all true, by the way. "I was posing a question," he says of his book.
But faster than you can say, "So what?" this zippy read has attracted threats of defamation lawsuits from researchers in East Africa and even from within Berger's own university.
Early in his career, Berger recalls solemnly, "I resolved not to take sides in any departmental rivalry and privately pledged my loyalties to the science as a whole."
In many ways, he sees himself as an innocent -- albeit cheerful -- victim of his own quest for truth. He fashions himself as the bearer of objectivity, the scientist unwilling to engage in the petty frays of his field.
"I take on White and Johanson with humility," he writes. "As a former disciple, I'm grateful for what they -- and my other mentors, Phillip Tobias and Richard Leakey -- have taught me."
Herein lies the contradiction. Though he stakes a position of humble supplication, Berger appears unable to resist firing rounds at the biggest names in the field. He christens Tim White the "Great White Shark . . . because of his aggressive intellect and inquisitor's mind." He repeats an anonymous co-worker's accusation that "Tobias eats his young," meaning his students. The famed Richard Leakey is a "virulent force in the profession."
Nor has Berger steered clear of departmental rivalries. The scientist dumped eminent fossil finder Ron Clarke from his Wits university post in 1998 -- just as he was uncovering a near-complete skeleton, the greatest find in university history.
A subsequent Johannesburg Sunday Times editorial cartoon included Berger's move among the "bloopers of the century," alongside a Decca Records executive telling the Beatles, "Guitar bands are on the way out."
In the book, Berger offers an uncomplimentary version of Clarke's early career and the firing. Clarke says it's all "lies" and is contemplating a defamation suit.
Equally telling is that former mentor Tobias is considering "legal counsel" Berger writes in his book that the elder scientist "engineered a coup" against him over the Clarke episode.
All of which has left Berger to preside over half of a divided empire.
He is director of PURE -- Paleoanthropological Unit for Research and Education -- which as of mid-August moved from the Wits medical school, where the fossils still reside. Recently, the university had to force the anatomy department director to give Berger keys to the fossil safe and 24-hour access.
Still, Clarke and Tobias, neither technically employed by Wits, hold the permit for the cave that houses Clarke's emerging skeleton. So Berger must run excavations of his own elsewhere. A foundation director told a South African newspaper that the infighting has started to scare off donors. It has also solidified Berger's reputation as a researcher who besmirches his friends to further his ambitions.
Berger's disputes involve more than conflicts of ego and name-calling, however. He is also raising hackles, and potential litigation, over what others deem his slovenly science. Count Berkeley's White among the colleagues contemplating legal action.
To the unschooled, White's beef may appear trivial. Berger's act of war was to characterize a 1998 find by White's team as "undescribed."
In the peculiar community of anthropology, however, this is a major slam. In essence, "undescribed" means that, until the discoverer publishes a formal anatomic description, the find isn't on the scientific map. It also can imply that the discoverer is hiding his find so that others can't study it, or that he just hasn't done the work necessary for publishing.
This, in turn, means that foundations may be reluctant to fund additional expeditions.
But there's a significant problem with Berger's allegation. That's because White's team did publish its description in April 1999. "It damages my reputation to be characterized as someone who is actively hiding fossils," White says.
Henry McHenry, who collaborated with Berger on a research project, hints that White is "overreacting," since Berger did mention "preliminary accounts."
But even McHenry, the colleague Berger portrays most favorably, is a bit "disturbed" by what he reads in both books and articles. The extremely soft-spoken University of California-Davis professor worked with Berger on two scientific papers.
In 1998, McHenry read a draft of a National Geographic article that Berger prepared on their research. "I was appalled at the way he invented a story and put words in my mouth," he says.
McHenry, who received a copy of In the Footsteps of Eve autographed to "a good friend and inspiration," says both article and book oversimplify the work, making suggestions sound like firm conclusions.
"It's a little too bad," he says. "If he'd sent it to colleagues and had the glitches worked out . . . "
Others point out that Footsteps contains more than mere glitches. The book is riddled with errors.
"It's the most poorly edited book I think I've ever read," says Cleveland's Latimer, having cleared space among the mounds on his desk for a two-page longhand list of errors.
Critics say Berger's book is rife with errors in measurements, species names, places, and dates. Geographical descriptions are butchered, scholars placed at the wrong universities. Worse, from the provincial vantage point, is that Cleveland is dissed. Berger writes that Johanson took his collection from the Lucy find to California for study.
Perhaps emblematic of Berger's personality, and why his peers dislike him so, is a scene he describes two-thirds of the way into Footsteps.
As Berger casts it, he and Tobias had written a short paper. Ohio's Latimer and Lovejoy just happened to be in South Africa, part of a large group dubbed the "Dream Team" visiting Wits to examine fossils at the time. The Ohio men considered the paper bad science.
In gasping prose, Berger describes the incident as intensely as any courtroom drama.
"I felt uneasy as I took up my chair," he writes. "It was judgment day . . . [Latimer] had the air of a determined prosecutor intent on putting someone away for a long, long time. It became clear that the Dream Team had rehearsed this scenario . . . I began to feel more like a heretical young priest appearing before an inquisition trial in the Middle Ages . . . Taking a slow, deep breath, I began my argument."
They debated for hours about joint curves and ligament attachments.
Berger recalls a "sense of triumph" after the debate, himself the lone wolf taking on the titans of anthropology and battling them to a draw.
Yet members of the "Dream Team" describe this version as fiction.
Here's how Lovejoy recalls the debate: ". . . We took out the paper and [point by point] we said, 'Why'd you say this?' Each time he wouldn't have an answer. Finally he said, 'Okay, you're right.'"
White says Maeve Leakey, a neutral party, concluded that Berger's fossil was so badly damaged one couldn't tell anything conclusive about it. This doesn't show up in the book.
More important, the bones, according to Latimer, would blend perfectly with the First Family collection, leaving nothing concrete to alter Lucy's status.
Latimer says the whole meeting was more "fun" than portrayed and certainly not rehearsed. "We didn't even know we were going to see him. He happened to be there."
Personalities aside, the criticism of Berger boils down to this: The guy's discoveries just aren't fresh.
One of the advisers who oversaw Berger's 1994 doctoral dissertation in South Africa -- Jeffrey K. McKee, who moved to Ohio State University four years ago -- says he paged through Footsteps in a bookstore, but set it back down. "Most of what I saw was fiction."
He asks students to "rip apart" the original research published by McHenry and Berger: "My graduate students can see through their arguments."
Colleagues say Berger has yet to uncloak any appreciable differences between the South African fossils and Lucy's kind. He's discovered few new remains on his own thus far, relying instead on what's in the Wits safe. And, even if Berger eventually does undercut Lucy's place as the matriarch of humankind, "So be it," says Johanson, who since leaving Cleveland founded and directs the Institute of Human Origins, affiliated with Arizona State University.
So when other scientists look at Berger's argument, they say he's merely trying to manufacture drama.
"It's wishful thinking," Johanson says. "Just about everyone who has looked at this says it's wishful thinking."
Berger's "a fun guy to have a beer with," Latimer says, flashing one of his frequent toothy grins. "He's pretty young and exceedingly ambitious. I'm unimpressed with his science to date."
Latimer says he and his colleagues dismiss Berger's argument only after going over the data. "These are well-known, world-famous scientists. He gives the impression they're defending their case not because of the science, but because of their personalities."
Likewise, his opponents suggest Berger frames his theory as a rivalry between eastern and southern African fossils to enhance his own standing in his university and country. Looky here, is the message, I'm bringing you attention.
"He's trying to create a war that doesn't exist between South Africa and East Africa," White says. "It's done for political purposes."
Berger expected this. He wrote that his theories would cause "vociferous opposition" from the paleoanthropology powerhouses. It seems he welcomed it opposition has made people famous.
Cheerfully, Berger stands by his words. "I think [the book] speaks for itself," he says. "I don't think there's any antagonism there.
"This science is enormously exciting, enormously vibrant. It's a shame people look to the negative of the science."
He concedes the book's basic errors involving names and dates, but attributes them to standard problems inherent in publishing. "That happens in the first edition, I think.
"I'm just putting forth what's there. It's not the most comfortable thing in the world, but it's not antagonistic."
You can almost hear Berger smiling through the transoceanic wire: "We're studying humans. People feel more poignantly attached to it. People like Tim and Owen and Bruce are fantastic scientists. Things get hotly contested."
There also remains this question: If Berger is such a minor leaguer, why do his dismissive colleagues have so much to say about his book?
Some of the criticism involves money. A good professional reputation takes decades to achieve. If a foundation official read Berger's attacks on his colleagues, without the benefit of rebuttal, expedition money could well dry up. There's also the concern that Berger's book, written to be more accessible than the standard academic text, may be a reader's first introduction to the field -- and an error-filled one, at that.
One can't help but get the impression that peers see Berger as an inferior scientist, who's nonetheless landing plum National Geographic assignments, 10-city book tours, and gobs of press attention.
From his 10 years in South Africa, Ohio State's McKee remembers two main characteristics about his former student: His raw writing needed a lot of editing, and "From day one he wanted to take over."
White is especially dismayed by Berger's style, which he thinks represents a larger trend. The science, he says, "is seriously damaged by this rise of careerism and the sort of naked politics being played."
As is his custom, Berger sees the fight in more romantic terms, assuming the role of good guy taking on the establishment: "Do you ever feel at the root of this, that people don't like to make this science accessible?"
The Berger brouhaha is just the latest in a century of paleoanthropologists wielding fossilized jawbones against perceived philistines. There are some memorable donnybrooks to look back to, recounted in books like Johanson's Lucy, Richard Leakey's Origins Reconsidered, or journalist Roger Lewin's Bones of Contention. Sir Grafton Elliott Smith and Sir Arthur Keith, leaders of British paleoanthropology early in the century, recommended Raymond Dart to head the anatomy department at Wits's medical school. When he turned up a child's small-brained skull and named it A. africanus in 1925, they publicly spoke of his intellectual and emotional weaknesses. Keith admitted he was wrong 22 years later.
Despite some later wacky theories, Dart is a hero in the profession.
Meanwhile, Smith and Keith themselves fell out over interpreting Piltdown Man, a British scientific gem discovered in 1912 that was eventually unmasked as a fraud 40 years later. No one has solved the mystery of the forgery, but the suspects include two scientists who intensely hated Keith and Sir Arthur Smith Woodward. The latter first studied the find and wasted decades of his career fruitlessly searching for more specimens.
Keith's most famous student, Louis Leakey, and his family are legendary. His wife, Mary, son Richard, and Richard's zoologist wife, Maeve Leakey, all made spectacular finds. But colleagues paint the Leakeys all as spectacular characters -- except Maeve, the nice one. At one point or another, everyone in the family was fighting: Richard with each parent, Louis and Mary with each other. A lot of rivals used to needle Richard for having no academic degree, despite his skill in organizing expeditions.
The Leakeys were at first close friends with White, who worked on Mary's team, and Johanson, who visited on his way to and from early expeditions. During campfire debates, Mary would tell them, "That's right stick to your guns." Before the trip that yielded Lucy, Johanson bet Richard a bottle of wine he would find older fossils than his.
The family vehemently disagreed with White and Johanson over the Lucy find. The idea of placing this small-brained creature at the base of the family tree was abhorrent to the Leakeys, who wanted to prove a large brain evolved millions of years earlier. Mary Leakey called Johanson and White "not very scientific" Johanson shot back that paleoanthropology's matriarch "really shows a poor appreciation of what evolution is all about." When she retired, it galled her that Johanson and White started working her stomping grounds at Olduvai Gorge. Johanson won the bet, but never got his bottle of wine.
Since those days, the seemingly inseparable White and Johanson have also parted ways. They'd rather not talk about it.
"Tim is a very sweet person in some contexts, but he is a great white shark in others," McHenry says. "He's turned his rage on so many people. I've seen it at meetings. I can list a lot of people he's attacked."
Yet even though the Berger slugfest matches those historic fights in terms of vitriol, Clarke is quick to distinguish its lack of scientific import.
"Sir Arthur Keith was an eminent scientist," Clarke says. "Louis Leakey was a charismatic personality. But also he had a brain . . . Tim White would not write a book telling lies about Don Johanson.
"Where are the discoveries Berger has made? He's written a book based on other people's discoveries, and he's misinterpreting or misrepresenting what they've written."
"For some reason, paleoanthropology attracts a lot of strong personalities," says McKee at Ohio State. "The rest of us just go about doing our work and disagreeing at meetings, and then go out and have a beer with the people we disagree with."
Nor are battles particularly unusual in any realm of science. Latimer tells the story of renowned evolutionary biologist Edward O. Wilson. At one conference, a rival dumped a pitcher of ice water on his head.
By contrast, the fossil-hunters seem tame. They give insult, for example, by refusing to put a rival's name for a species in italics. Write about Homo habilis instead of Homo habilis, and you were sure to inspire a stern letter from a Leakey.
All of which has anthropologists expressing their greatest fear: that Berger's needlessly combative book will obscure an important field.
Randall Susman, anatomy professor at the State University of New York at Stony Brook, says his colleagues should just ignore the book.
"It's like third grade, when somebody defames your lunch and you'll sue. In our field, the principle seems to hold that negative attention is better than none.
"So many of these books just stir up the mud, and they don't have to, because [the science is] intrinsically interesting."
When these guys look at bones, they're seeing whole stories -- how bone density might indicate the strength or heavy use of a limb how the shape of a vertebra determines posture or hints at nerve connections.
So they ask the bones questions: How did these creatures walk? What did they eat? How much time did they spend in trees? Can we tell gender from a skeleton, and was there a great size difference between males and females? If there is, does that mean the males had harems like gorillas?
They also think about the environment of five or so million years ago. The weather was drying up, and rain forests were shrinking. What could an animal do to increase its chances for more offspring? How would that strategy incorporate all the other changes that show up step by step in the fossils -- first walking, then tools, then bigger brains?
Despite the 99 percent of our DNA that we share with chimps, we are quite different animals. We are, for instance, the only primate without a clearly defined breeding season, other than closing time at the Flats. Nor do women's butts turn red when they ovulate.
Kent State's Lovejoy has developed a theory that connects a lot of these questions -- mating, walking, social structure -- into a strategy for why Lucy's kind could presumably bear more babies than an ape. And he has a lot of detractors. But they still respect his knowledge and focus on function.
This shouldn't be confused with universal cheer, however. Kent State's Lovejoy says 90 percent of paleoanthropologists could be accused of scientific "malpractice" -- including McHenry and Susman.
"I will argue that human paleoanthropology is the most difficult of all sciences," he says, but the public and most of the people who enter the field think they understand human evolution simply "because they are human." It's not enough to "look at bones and make up stories."
The past 30 years have brought advances in the studies of mammal movement, genetics, ecology, even orthopedic surgery, says Lovejoy, who also teaches in the orthopedics department at Case Western's medical school. All of these have a bearing on human evolution.
"The anthropologists have watched it go by like a car," he says. "Anthropologists tend to read stuff written by other anthropologists. That's one of the reasons it's a dead science.
"There's a vast supply of knowledge with which to interpret the fossil record, and almost none of it is being used."
This is why Lucy remains safe, even if one day we no longer call her great-grandma. Secretive little lady that she is, she still gives us so much to fight about.
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Prehistoric teeth fossils dating back 9.7 million years ɼould rewrite human history'
Paleontologists in Germany have discovered 9.7 million-year-old fossilised teeth that a German politician has hailed as potentially “rewriting" human history.
The dental remains were found by scientists sifting through gravel and sand in a former bed of the Rhine river near the town of Eppelsheim.
They resemble those belonging to “Lucy”, a 3.2 million-year-old skeleton of an extinct primate related to humans and found in Ethiopia.
However, they do not resemble those of any other species found in Europe or Asia.
Scientists were so confused by the find they held off from publishing their research for the past year, Deutsche Welle reports.
Herbert Lutz, director at the Mainz Natural History Museum and head of the research team, told local media: "They are clearly ape teeth. Their characteristics resemble African finds that are four to five million years younger than the fossils excavated in Eppelsheim.
“This is a tremendous stroke of luck, but also a great mystery."
At a press conference announcing the discovery, the mayor of Mainz suggested the find could force scientists to reassess the history of early humans.
"I don't want to over-dramatise it, but I would hypothesise that we shall have to start rewriting the history of mankind after today," he said.
Axel von Berg, a local archaeologist, said the new findings would “amaze experts”.
With the first paper on the research having just been published, the “real work” to unlock the mystery is only just beginning, Dr Lutz said.
Although there is abundant fossil evidence that great apes were roaming Europe millions of years ago, there has been no confirmed cases of hominins – species closely related to humans – on the continent.
Lucy in the trees? Our ancient relative may have had strong climbing arms
Scientists may have just found the smoking gun that the ancient human relative, Australopithecus afarensis, swung from trees like chimpanzees.
One of the first things that paleoanthropologists noticed about the fossil primate they dubbed "Lucy" was that she could have walked upright, on two legs. This ability, bipedalism, placed the 3.2-million-year-old human relative at the evolutionary cusp between humans and our precursors.
But a question remained: Did she, also, climb trees regularly, like the nonhuman primates? The answer would help determine just how humanlike Lucy and her species, Australopithecus afarensis, was and could even yield clues about the conditions that led to our own evolution.
Now, scientists say they have incontrovertible evidence that Lucy was up in the trees – a lot. And the clues, they say, lie in her bones.
"This study puts a sturdy nail in the coffin of the notion that our early Australopithecus ancestors no longer climbed trees as part of their normal behavior," Brian Richmond, curator of human origins at American Museum of Natural History in New York who was not involved in the new study of Lucy's bones, writes in an email to The Christian Science Monitor. "If anyone was still sitting on the fence about this debate, the fence just fell over."
Most previous evidence fueling the debate over whether Lucy was a tree climber focused on whether her skeleton allowed such motion. For example, the A. afarensis shoulder socket is structured more like that of modern nonhuman apes, who are adept tree climbers, than modern humans. And, on the other side, Lucy's foot may have had an arch, which would have made her much more well-adapted for life on the ground than in the trees – like modern humans.
Inheritance, fairness, and the billionaire class
But, as any parents of risk-taking children know, Homo sapiens can climb trees too.
So Christopher Ruff, a paleoanatomist at Johns Hopkins University School of Medicine in Baltimore, and colleagues at the University of Texas at Austin decided to look for evidence of tree-climbing behavior actually being performed.
The characteristics of bones aren't entirely determined by genetics, Dr. Ruff explains in a phone interview with the Monitor. Some of the strength of an animal's bone can be altered by how it is used in life. For example, he says, scientists have found that the bones in professional tennis players' racket arms tend to be stronger than those in their non-racket arm.
So Ruff and his colleagues studied the scans of the internal architecture of Lucy's arm and leg bones, and compared them to modern great apes and humans.
In modern humans, who spend very little time in the trees, the arm bones are relatively weak compared with leg bones. But in chimpanzees, who swing, snack, sleep, and seek shelter in trees, that ratio looks very different.
"We don't think that Lucy was playing tennis, so if she had strong upper limb bones, there's really just one explanation for it: She was probably using them to pull herself up," Ruff says. "And it turns out she did."
Lucy's bone strength suggested she was both frequently walking on both legs on the ground and clambering around in the trees, Ruff and his colleagues report in a paper published Wednesday in the journal PLOS ONE.
"The evidence is convincing but the conclusions are not really new," David Begun, a paleoanthropologist at the University of Toronto who was not involved in the research, writes in an email to the Monitor. "Since the 1980s, there has been a debate about Australopithecus locomotion and the degree to which it included arboreality, with most researchers including myself concluding that they were much more arboreal than Homo erectus or later Homo (but maybe not Homo habilis). It is nice to have CT scan data and cross-sectional data but it only confirms most previous analyses."
But Carol Ward, a paleoanatomist at the University of Missouri who also was not involved in the study, disagrees.
"The evidence that they present is compelling to suggest that she had bigger, stronger upper limbs than we do," she tells the Monitor in a phone interview. But, Dr. Ward says Lucy and her relatives, lacking a grasping foot, were poorly suited for adept tree-climbing.
Through natural selection "they gave up most of the things that make you good at climbing," she says, so there must have been strong selection toward bipedality and against tree-climbing.
Why the strong arms then? It could be some other behavior, Ward says, perhaps throwing things became advantageous for these bipedal primates, for example.
"We know apes climb trees, she seems more apelike, so a natural hypothesis is that that's because she climbed trees some too. It's a perfectly viable hypothesis," Ward says, "But I think we as scientists need to keep in mind that there may be other reasons that Lucy and her relatives changed when they evolved into our genus Homo."
But, Dr. Richmond points out, "living life permanently on the ground comes with serious risks because of the exposure to many large predators." So evolving to live a less apelike life outside the trees would require other means of protection.
Randall Susman, chair of the department of anatomical sciences at Stony Brook School of Medicine in New York who was not involved in the research, agrees. "If I'm going to come to the ground, I'd want to retain the possibility to get up a tree if I had to," so retaining a few tree-climbing traits while Lucy and her relatives were adapting to life on the ground would have helped them survive.
Not only that, Dr. Susman says, no nonhuman primate the size of Lucy (at three-and-a-half feet tall) that lives today lives entirely on the ground. Most nest in the trees, munch on fruit in the trees, and escape predators in the tees. "That animal would have been living in trees using every living primate model that we have today," he says.
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Life in the trees is clearly very important to humans' closest relatives, the other primates, so scientists want to understand what changed in our lineage.
"At some point, living on the ground required a shift in social strategy, weaponry, and use of defenses like fire to keep our ancestors safe from predation," Richmond says. So scientists see the stage at which our ancestors abandoned any last arboreal adaptations as a key "shift towards 'becoming human'."
Two Montana Sweethearts Were Fatally Shot in 1956. The Case Was Just Solved.
When Detective Sgt. Jon Kadner of the Cascade County Sheriff’s Office in Montana was told in 2012 that he was being put in charge of the investigation into a long-unsolved double homicide, the case was already more than 50 years old.
It was the first time that Kadner, who is 40 and grew up in small-town Iowa, had heard of Duane Bogle and Patricia Kalitzke, teenage sweethearts who had been fatally shot in January 1956, more than two decades before he was born, presumably after they drove to an area known as lovers' lane in Great Falls.
“There was just years and years of documentation and numerous suspects that had been looked into,” Kadner said. “But I knew the key was going to be DNA.”
On Tuesday, the Cascade County Sheriff’s Office announced that it had cracked the case. The office identified Kenneth Gould, a horse trainer who died in 2007 at age 79, as the “likely suspect” who had shot and killed Bogle, 18, and Kalitzke, 16, more than 65 years ago.
Kadner said he believed it was the oldest homicide case in the United States to be solved with genetic genealogy, which uses DNA from crime scenes to identify the relatives of potential suspects and eventually the suspects themselves.
John Butler, an expert on forensic genetics at the National Institute of Standards and Technology, said while he was not aware of any group that officially tracks cold cases, “Certainly, 1956 is the oldest that I have heard about up to this point.”
The investigation involved painstaking research into a long-ago crime that had once generated national media attention.
Kalitzke was a junior at Great Falls High School. Bogle, an airman from Waco, Texas, was stationed at nearby Malmstrom Air Force Base. They both loved dancing and music, and he was “instantly smitten with Patty,” when they met in December 1955, Kadner said.
The teenagers were last seen at Pete’s Drive-In restaurant in Great Falls, just after 9 p.m. on Jan. 2, 1956. When they didn’t come home that night, their families assumed they had eloped, Kadner said.
The next day, three boys hiking along the Sun River in Great Falls found Bogle’s body in an area that was known as a rendezvous spot for teenagers.
He was facedown and had been shot in the back of the head. His hands were tied behind his back with his own belt. The ignition switch, radio and headlights on his car were on, and the car was in gear. His expensive camera had not been taken.
Investigators initially feared that Kalitzke had been kidnapped.
But the next day, Jan. 4, a county road worker found her body off a gravel road about 5 miles north of Great Falls. She had been shot in the head and had injuries that were consistent with a struggle or a sexual assault, Kadner said.
Newspaper headlines described the teenagers as “lovers’ lane slaying victims” and recalled a “wide search” for a “brutal killer.”
Over the next half-century, detectives investigated about 35 potential suspects, including James (Whitey) Bulger, the notorious South Boston mobster who was convicted in 2013 of participating in 11 murders. Bulger, who died in 2018, had lived in Great Falls in the 1950s and had been arrested in a rape there in 1951, Kadner said.
But no one was ever charged, and the case went cold.
Investigators turned to genetic genealogy in 2018, after the authorities arrested Joseph James DeAngelo, known as the Golden State Killer and accused him of committing 13 murders and nearly 50 rapes that terrorized California in the 1970s and ’80s. It was the first high-profile case to be cracked with genetic genealogy.
“That’s when we really started looking at what evidence we had and if we could potentially do the same thing,” Kadner said.
Kadner said the crucial piece of evidence was a DNA sample from a sperm cell that had been collected from Kalitzke’s body during her autopsy. That sample had been preserved in an evidence vault for six decades.
In 2001, it had been sent to the state crime lab for analysis, but it did not lead to any matches in a national criminal database.
In 2019, with the help of Bode Technology, a Virginia company that specializes in DNA analysis, another DNA profile was extracted from the sample, which enabled investigators to build a family tree that led them to Gould, Kadner said.
Because Gould had been cremated, investigators collected DNA from his children, which linked Gould to the sperm cell that had been found on Kalitzke’s body, Kadner said.
Gould, who was 29 in 1956, lived just over a mile from Kalitzke’s house and kept horses about 600 yards from the house where she had grown up, Kadner said. He had married another 16-year-old girl in 1952 and eventually had five children.
After the killings, he left the area and was seen living in two other Montana towns before moving to Alton, Missouri, in 1967.
He never returned to Montana, even to visit his family, Kadner said. Gould had no known criminal history, and detectives do not know if he had any relationship with Kalitzke or Bogle. Gould died in Oregon County, Missouri.
“Obviously, I can’t put the gun in his hand,” Kadner said. “But when you put everything together, there’s no doubt in my mind that he’s the suspect.”
Gould’s children, three of whom submitted DNA samples, were all surprised to be told that their father was being investigated in connection with a double homicide in 1956, Kadner said.
“His daughter basically said, ‘You never know. Some people just have secrets that they never told anybody,’ ” Kadner said.
Kalitzke’s sister has advanced dementia, Kadner said. Bogle’s brother died in 2013. Based on conversations with his wife, “it really affected him throughout his life, just not knowing what happened to his brother,” Kadner said.
Kadner said it was “pretty surreal” to have identified the likely suspect in two homicides that took place so long ago. “I’ll be honest,” he said. “It feels great to give this family closure.”
10 Significant Recent Evolutionary Discoveries
The theory of evolution via natural selection completely transformed the world of science 150 years ago and its ramifications rippled across all aspects of life, including politics and religion. It is as well accepted in the world of biology as the Earth orbiting the Sun is in astronomy, but is perhaps the most socially divisive issue in science. Whilst the reality of evolution is well known there is a lot of detail to figure out in its 3.5 billion year history. These are ten of the most important discoveries from the last decade that are helping science fill in the picture.
Discovery: Butterfly supergenes demonstrate unknown method of inheritance
The butterfly species Heliconius numata has long proved a mystery. Its population carried seven different discrete wing-patterns, each specified by a combination of many different genes. When parents with different wing patterns mate genes get shuffled and spread out and these patterns should quickly merge together. The traditional Mendelian inheritance model we all learned in school breaks down where multiple genes are involved.
A team of British and French biologists discovered in 2011 the presence of what they called a supergene, a cluster of eighteen genes passed down in a single unit. Rather than having a mixture of genes from each parent, offspring inherit particular dominant and recessive supergenes, allowing the discrete trait to carry on. The butterfly holds other mysteries, such as why seven patterns are used to scare off birds, when one would normally suffice, but at least the how has been cracked.
Discovery: Human and chimp interbreeding
It&rsquos well known that chimpanzees are humankind&rsquos closest surviving relative. Crossbreeding the two species has captivated the imagination for over one hundred years [http://en.wikipedia.org/wiki/Humanzee] and theories abound about attempts by Soviet scientists. There are some that believe a human-chimp hybrid named Oliver survived until last year, though DNA testing has proven he was just a normal chimp that displayed human-like traits.
Luckily for many of the internet&rsquos quirkier inhabitants, genetic analysis from 2006 suggests that human and chimpanzee ancestors continued to interbreed after their initial split 6.3 million years ago. In fact, it was apparently so hot they saw fit to keep at it for 1.2 million years. These results were unexpected and might open up a new avenue of exploration into the history of life. As study author David Reich explained, &ldquoThat such evolutionary events have not been seen more often in animal species may simply be due to the fact that we have not been looking for them.&rdquo
Discovery: Decades-old bat mystery finally solved by intriguing fossil
Bats are the second largest order of mammals, accounting for a fifth of all mammalian species. They&rsquore the only mammals to have developed full flight and can use echolocation to a level unmatched by any other land-dwelling creature. These archetypal traits have been the subject to a longstanding mystery within biology&mdashwhich came first? (For the related question, it&rsquos apparently the chicken).
A pair of fossils discovered in Wyoming in 2003, part of a new species dubbed Onychonycteris finneyi , has many odd features. It has claws on all five fingers, compared to the one or two found on modern bats, possibly as an adaptation for climbing in the forest canopy. More importantly it has the capacity for flight without the ability to echo-locate, confirming flight came first. Joining the dozens and dozens of other transitional fossils completely invisible to creationists, the fifty-two million year old specimen ends decades of speculation amongst scientists.
Discovery: Tiktaalik provides missing link between fish and land animals
One of the most profound transitions in the history of life was the move from water to land. Tetrapod is the name given to the first creatures to leave the water and the name means four limbs. The first tetrapods are the ancestors to all living reptiles, amphibians, birds and mammals. Scientists have long understood that tetrapods evolved from lobe-finned fish, the most famous example of which is probably coelacanth. For a long time, however, there was no evidence to show when the soft fleshy fins began to turn into bony limbs, with estimates all the way from 400 to 350 million years ago.
Tiktaalik, discovered in 2004 in Nunavut, Canada, changed all that. Labelled a missing link, Tikaalik was the first fossil that is still a fish but displayed the beginnings of digits, wrists, elbows and shoulders. It&rsquos about as transitional as a fossil can be. Tiktaalik is as profoundly transitional as a fossil can and was dubbed a fishapod by one of its discoverers. The fishapod nano and fishapod classic remain elusive.
Discovery: Lice offer a new window into the history of mammals
Advances in genetic testing have opened up windows into the past that were undreamed of even fifty years ago. Lice, which have been irritating human scalps for tens of thousands of years, offer a unique method to exploit this. Lice are specialists with claws adapted to their host, so when their particular meal of choice evolves into a new species, the lice follow suit. This precision in lice speciation means that louse family trees based on DNA can be dated precisely with just a few fossils to act as anchors.
DNA testing of lice was done by a (probably really itchy) team of researchers at London&rsquos Natural History Museum, offering implications for our knowledge of the evolution of birds and mammals. The researchers found that bird and mammal lice began to diversify before the extinction of the dinosaurs, suggesting that, contrary to the prevailing theory, mammals may have formed some of today&rsquos major groups before the extinction of the dinosaurs. The alternative but equally awesome possibility is that our lice come from a lineage that used to eat the blood of dinosaurs.
Discovery: Giant amoeba casts doubt on when symmetrical life originated
One of the earliest fundamental traits to evolve in the animal kingdom is that of bilateralism. If you divide a human in two from top to bottom through the middle you will have, for the most part, the same things on both sides. You can halve everything from flatworms to sharks to elephants to find the same mirror image, though you&rsquod have a big mess and questions to answer afterwards, but you&rsquod be demonstrating that bilateral symmetry is found everywhere. Such a key trait has been subject to much speculation as to when it arose and some of the best examples of evidence were 550 million year old sea-floor tracks. The creation of these particular tracks by creatures moving in a straight line was thought only possible by creatures with two halves.
A 2007 discovery by researchers from the university of Texas cast serious doubt on those conclusions. Whilst diving off the coast of the Bahamas (sucky job, we know), Dr Mikhail V. Matz and his team filmed an inch-wide amoeba, a single celled creature, rolling along the sea floor. The creature propels itself by exuding protoplasm, and has a water-filled core to help maintain its shape. It left tracks strikingly similar to those found in fossils, suggesting that bilateralism may actually have developed tens of millions of years later than first thought.
Discovery: The Neanderthal genome project suggests we&rsquore related
Neanderthals are the species that was almost us. There is evidence to suggest they were as intelligent as humans, physically stronger and had developed many aspects of culture before their extinction less than 30,000 years ago. Because they died out so recently it has been possible to isolate their DNA. In 2010 a team from Germany&rsquos Max Planck institute published a draft sequence of the Neanderthal genome less then a decade after the mapping of the human genome was completed.
The sexiest headline picked up on at the time was that one to four percent of DNA in modern humans could be traced to neanderthals, which may be evidence of interbreeding between the two. A paper published last year doubts this conclusion, suggesting a common ancestor as the origin of these shared genes, but the original researcher is standing by the jiggy-with-it hypothesis and has published another paper to support it.
Open questions are the lifeblood of science and this one is unlikely to be definitively settled for some time. The key thing to take away from this, though, is that Neanderthals weren&rsquot too unlike us at all.
Discovery: Lucy&rsquos Baby steals Lucy&rsquos thunder
The most famous early human ancestor is probably Lucy, the 3.2 million year old skeleton found in 1974. Though only forty percent complete, Lucy became synonymous with the birth of humanity. Her species, Australopithecus afarensis, was at the time the oldest one known from the time after we split from our common ancestor with chimpanzees. Yet Lucy&rsquos thunder was stolen by the discovery of another Australopithecus afarensis fossil in 2006.
Though predating Lucy by tens of thousands of years, the new fossil was nevertheless dubbed Lucy&rsquos baby. The child was probably female and believed to have died at around age three. Being a child skeleton makes it extremely rare. It is also more complete than Lucy. The child, who was still at nursing age, will add greatly to our knowledge of human ancestry but it&rsquos hard not to be touched by the descriptions of tiny fingers and a knee cap no bigger than a dried pea.
Discovery: Ardi is oldest human ancestor ever found
Whilst we&rsquore on the subject of stealing Lucy&rsquos thunder, meet Ardi, the fossil that stole Lucy&rsquos crown as the oldest known probably human ancestor in 2009. Ardi was a 110 lb (50 kg) small-brained female and she predates Lucy by more than a million years. She was found with the remains of thirty-six other individuals. Part of a new species, Ardipithecus ramidus , Ardi was actually found in 1994 but it wasn&rsquot until 2009, after a decade and a half of painstaking analysis, that the implications became known.
Since the time of Charles Darwin there was a popular notion that our common ancestor with chimps would be like, well, chimps. But chimps have had as long to evolve as we have and there&rsquos no real reason to think our ancestors would be closer to either of us&mdashArdi casts a definitive blow to the old idea. She shows an unexpected mix of traits both advanced and primitive, unlike chimps or gorillas. As anatomist Owen Lovejoy, who analyzed parts of Ardi, put it, she shows a &ldquovast intermediate stage in our evolution that nobody knew about.&rdquo And if there&rsquos one contribution to science greater than any other, it&rsquos a vast anything that nobody previously knew about.
Discovery: Junk DNA isn&rsquot junk after all
When the human genome project&rsquos first draft was presented in 2000, ninety-seven percent of the 3.2 billion bases in the sequence were without apparent function. The primary function of DNA is to provide the designs for proteins, information which is stored in genes, but these constitute just three percent of a DNA strand. Scientists had long known of this noncoding DNA and the description &ldquojunk&rdquo to describe it was coined way back in 1972. Even noble laureate Francis Crick, co-discoverer of the double-helix, was quoted as saying most of the key to life was &ldquolittle more than junk&rdquo.
In September 2012 the international Encode project published a map of four million switches to be found in junk DNA, switches that regulate the protein-coding genes. Scientists from the project say up to eighty percent of the DNA sequence can be assigned some sort of biochemical function. Less than half a year on, the results of this shift in thinking are already showing: scientists from MIT have identified a portion of noncoding DNA that is fundamental to the development of heart cells, whilst other scientists have found mutations in noncoding DNA that appear to be a key cause of skin cancer. Both of these discoveries have potential medical applications and scientists are likely only scratching the surface.