LiveScience Susan Hayes’ facial approximation of the female Hobbit. Credit: University of Wollongong



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Real-Life 'Hobbit' Face Revealedhobbit-278

Analysis by DNews Editors


Tue Dec 11, 2012 10:33 AM ET

By Megan Gannon, News Editor, LiveScience
Susan Hayes’ facial approximation of the female Hobbit. Credit: University of Wollongong

Researchers have revealed what the face of a controversial ancient human nicknamed "the Hobbit" might have looked like.

"She's not what you'd call pretty, but she is definitely distinctive," said anthropologist Susan Hayes, a senior research fellow at University of Wollongong, New South Wales, Australia. The female doesn't have feminine-looking big eyes and she's lacking much of a forehead.

With a background in forensic science, Hayes was able to flesh out the face of the 3-foot (1-meter) tall, 30-year-old female based on remains that were uncovered in the Liang Bua cave on the remote Indonesian island of Flores in 2003. To come up with this facial depiction, Hayes uploaded information from 3D imaging scans of the skull into a computer graphic program and also looked at portraits by paleo-artists of the Hobbit, finding these earlier interpretations were skewed toward monkey features; her examination, meanwhile, suggested modern features were more accurate, according to the Sydney Morning Herald.

The 18,000-year-old skeleton, officially known as Homo floresiensis, gets its nickname from its squat stature. The Hobbit would have weighed between 66 and 77 pounds (30 and 35 kilograms). Since the discovery, scientists have debated whether the specimen actually represents an extinct species in the human family tree, perhaps a diminutive offshoot of Homo erectus, a 1.8-million-year-old hominid and the first to have body proportions comparable to those of modern Homo sapiens. (See Images of Homo Floresiensis)

Critics have argued that the remains could have belonged to a human with microcephalia, a condition characterized by a small head, short stature and some mental retardation. But a 2007 study — which revealed that the Hobbit's brain was about one-third the size of a modern adult human's brain — found that its brain region ratios were inconsistent with those characteristic of microcephalia. "In our view we dispensed at that point with the microcelpahy hypothesis," said Florida State University anthropologist Dean Falk, in 2009 when a skeleton cast of H. floresiensis went on public display for the first time at Stony Brook University on Long Island. "It's not just that their brains are small; they're differently shaped. It's its own species."

Also in 2007, work by Matthew Tocheri, an anthropologist at the National Museum of Natural History in Washington, D.C., and colleagues found the female Hobbit's wrist bones matched, in shape and orientation, those of non-human apes; they looked much different from the wrist bones of Neanderthals (Homo neanderthalensis) and modern humans, also pointing to a new species.

The Hobbit face was unveiled at the Australian Archaeological Conference being held from Dec. 9-13 at the University of Wollongong.

Hayes, who prefers the term "facial approximation" to "facial reconstruction" for her work, said she was pleased with results.

"She's taken me a bit longer than I'd anticipated, has caused more than a few headaches along the way, but I'm pleased with both the methodological development and the final results," the researcher said in a statement. Her work has yet to be published in a peer-reviewed scientific journal.



Name of Scholar: _________________________ Date: __________

BWCCMS Class:__________

Real-Life 'Hobbit' Face Revealed

By Megan Gannon.

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Birds Descended from Gliding Dinosaurs

These gliding dinosaurs certainly had the edge on size, but modern birds are much better fliers.


By Jennifer Viegas
Wed Nov 21, 2012 12:01 PM ET

dino gliders

Archaeopteryx, illustrated here, had multiple layers of long flight feathers. Carl Buell, © Jakob Vinther

Evidence is mounting that modern birds descended from gliding, feathered non-avian dinosaurs.

Two dinosaurs could be candidates for the bottom of the bird family tree, and each helps to reveal how feathers first evolved.

"The oldest known feathered dinosaurs would be Anchiornis (155 million years ago) and Epidexipteryx (between 152 million and 168 million years ago)," Yale University paleontologist Nicholas Longrich told Discovery News. "Feathers seem to have appeared initially for insulation. Basically they start out as down, and later are used to make wings."

For a study published in the latest Current Biology, Longrich and colleagues Jakob Vinther and Anthony Russell examined fossils of Anchiornis huxley and of Archaeopteryx lithographica, a Jurassic species that could be the world's oldest known bird.

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"Where dinosaurs end and birds begin is a bit arbitrary," Longrich explained. "There's no clear cutoff that separates one from the other. That's the nature of evolution; things gradually change from one thing into another."

The scientists found that the wing feathers of Archaeopteryx and Anchiornis were similar, but not identical. The variations between the two appear to represent early experiments in the evolution of the wing.

Archaeopteryx had multiple layers of long flight feathers. In contrast, the dinosaur Anchiornis had an abundance of simple, strip-like feathers that overlap, somewhat similar to the feathers on penguins.

The design and arrangement of Anchiornis and Archaeopteryx wing feathers probably hindered liftoff. Multiple overlapping layers of long wing feathers would have complicated feather separation, minimizing the bird's ability to overcome drag on the upstroke. By contrast, the wings of modern flying birds typically have a single primary layer of easily separated long feathers overlain by short feathers.

"Modern birds have the ability to separate their wing feathers sort of like a Venetian blind," Longrich said. "This allows them to raise the wing rapidly, and seems to be critical to flapping flight at low speeds."

"The feather arrangement in Archaeopteryx and Anchiornis wouldn't let them do this," he added, "so it may have made takeoff from the ground and flapping at low speeds more difficult."

Gliding, however, must have been a lifesaver back in the dinosaur day, when huge terrestrial carnivores were stomping around.

"Gliding is a fast way to move from tree-to-tree. Instead of climbing down one tree and running up the next, you just glide quickly from one to the other," Longrich explained.

"I would imagine that the dinosaurian ancestors of birds were living in the trees," he noted, "probably to find food-like insects, lizards and mammals, and to avoid becoming food for other dinosaurs."

Longrich and his colleagues believe that the wing feather arrangement seen in modern birds may have evolved within a period spanning a few tens of millions of years and then remained largely unchanged for the past 130 million years.

In terms of this short versus long timescale, Longrich compared it to the evolution of human-constructed aircraft, which started with some years of experimentation before settling into a basic design that's just been fine-tuned during more recent years.

"Birds hit on a workable design about 130 million years ago, and it's been difficult to improve upon it," he said.

Birds benefitted from both this and their small size 65 million years ago, when the larger non-avian dinosaurs bit the dust.

Xu Xing, one of the world's leading paleontologists, is a professor at the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences. He told Discovery News that the determination about ancient versus modern feathers and wings "is definitively a significant discovery."



The study "has greatly improved our understanding of wing evolution," Xu continued. "(The authors) demonstrate that there are unusual wings near the dinosaur-bird transition, though more data is needed to confirm the claim that it is directly related to the origins of avian flight."

Name of Scholar: _________________________ Date: __________

BWCCMS Class:__________

Birds Descended from Gliding Dinosaurs


By Jennifer Viegas
dino gliders

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Great White Shark Origins Found

Analysis by Jennifer Viegas


Thu Nov 15, 2012 03:36 PM ET


shark-zoom

Great white sharks are among the world's largest living predatory animals, and now we have a better idea of their ancestors and how these toothy media superstars evolved.

Great whites turn out not to be very related to the extinct Carcharocles megalodon, the largest carnivorous shark that ever lived. Instead, they likely descended from broad-toothed mako sharks.

As you can see from the above photo, however, these sharks back in the day had impressive mouths and teeth too. The well-preserved fossil from Peru is the only intact partial skull ever found of a white shark that lived about 4.5 million years ago.

The species was named Carcharodon hubbelli for Gordon Hubbell, who donated the fossil to the Florida Museum of Natural History on the UF campus. The fossil jaw contains 222 teeth, some in rows up to six teeth deep.



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"The impetus of this project was really the fact that Gordon Hubbell donated a majority of his fossil shark collection to the Florida Museum," author Dana Ehret, a lecturer at Monmouth University in New Jersey who conducted research for the study as a University of Florida graduate student, said in a press release."Naming the shark in his honor is a small tip of the hat to all the great things he has done to advance paleontology."



Ehret studying the fossil

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He continued, "We can look at white sharks today a little bit differently ecologically if we know that they come from a mako shark ancestor."

That ancestor is 2 million years older than previously suspected, based on recalibrated dating.

Ehret said,"That 2-million-year pushback is pretty significant because in the evolutionary history of white sharks, that puts this species in a more appropriate time category to be ancestral or kind of an intermediate form of white shark."

He made the connection between modern great whites and C. hubbelli by comparing the physical shapes of shark teeth to one another. While modern white sharks have serrations on their teeth for consuming marine mammals, mako sharks do not have serrations because they primarily feed on fish. Hubbell's white shark has coarse serrations indicative of a transition from broad-toothed mako sharks to modern white sharks.

So the relatives of great whites used to eat more fish, but then switched to a more red meat diet consisting of mammal flesh.

The Pisco Formation in Peru where the shark fossil was found also includes new whale, marine sloth and terrestrial vertebrate species. I look forward to hearing more about those finds in future.

This question also now remains: Did the great Carcharocles megalodon just die out, leaving behind no modern ancestors? For shark fans, hopefully not.



Name of Scholar: _________________________ Date: __________

BWCCMS Class:__________

Great White Shark Origins Found

Analysis by Jennifer Viegas


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Ancestor Lucy Spent Time in Trees

Our closest relative 3.3 million years ago was a half-human, half-ape who could both walk on the ground and swing through trees.


By Jennifer Viegas
Thu Oct 25, 2012 01:20 PM ET
australopithecus afarensis

A model of Australopithecus afarensis from a Houston museum. New analysis shows this human ancestor was adapted both to walk on ground and swing from trees.


Zeray Alemseged / Dikika Research Project

Our closest known relative 3.3 million years ago was a half-human, half-ape species that could both walk on the ground and swing through the trees, suggests a new study.

The research, published in the journal Science, sheds light on Australopithecus afarensis, the species of the well-known "Lucy" skeleton. In this case, remains of a three-year-old A. afarensis girl, named "Selam," were the focus of study. Selam represents the most complete skeleton of her kind to date.

She and other members of her species were "very human-like from the waist down -- the hip bone, the knee and the foot -- but looked ape-like above the waist -- the torso, long arms, gorilla-like scapula, jutting snout, small brain and a skull with no forehead," co-author Zeresenay Alemseged told Discovery News. "A sketchy depiction of it would be an upright walking ape."



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Alemseged, curator of anthropology at the California Academy of Sciences, and David Green, an assistant professor in the Department of Anatomy at Midwestern University, made the determinations after thoroughly examining the well-preserved skeleton of Selam. In 2000, Alemseged unearthed her remains while excavating a site in Dikika, Ethiopia.

The researchers paid attention to Selam's two complete shoulder blades. These tend to be paper-thin, rarely fossilizing, so finding both "completely intact and attached to a skeleton of a known and pivotal species was like hitting the jackpot," Alemseged said.

The analysis of the shape and function of the bones revealed that A. afarensis had ape-like shoulder blades, indicating a partially arboreal lifestyle. Green explained to Discovery News that, during Selam's lifetime, A afarensis was a widespread species across East Africa that occupied a range of habitats, including wooden environments and gallery forests.

"Within this range of environments, Selam and her kin walked upright to move from one place to the other, but also had an arboreal lifestyle that enabled them to nest in trees, evade predators, and provision themselves," Green said. "This was a significant adaptation that enabled this short-statured hominin, with no sophisticated tools, to survive in a dangerous landscape filled with large felines and other carnivores."

The study reveals how apelike features in our ancestors were not merely evolutionary baggage, he continued. The traits instead reflect adaptations to habitat.

There is no question that Australopithecus afarensis is directly related to humans, according to the researchers.

"A. afarensis is clearly on the human line after the split from apes and eventually became ancestral to the genus Homo," Alemseged said. "It is currently hard to precisely talk about the exact number of species between us and A. afarensis."

Possibilities include A. africanus, Paranthropus, Homo habilis, Homo erectus and many others.

The authors also suspect that A. afarensis was not the first ancestor of humans to walk upright. This could be why Selam's bones indicate she walked with ease, at least when compared to chimpanzees that have been trained to do so. Chimps have a lumbering, awkward upright gait because they lack some important pelvic and lower limb characteristics that Selam possessed.

Walking upright might have been a breakthrough in our history, leading to a domino effect of other subsequent changes.

"If we look at later hominins, the proliferation of stone tools and the increased exploitation of animal proteins, it is clear that bipedalism enabled hominins to use their forelimbs to fashion and use tools and exploit this new niche (the ground environment)," Green explained. "Environmental change may have prompted this transition, and bipedal exploration of the terrestrial environment likely paved the way for stone tool use, manufacture and hunting."



"It is also plausible that this enabled subsequent expansions in brain volume, which is another hallmark of our lineage," he added. "Other primates may have been able to continue to exploit arboreal or other food sources, which did not require such a dramatic behavioral transition. The ability of early hominins to exploit new resources is probably why bipedalism may be viewed as a successful evolutionary experiment."

Name of Scholar: _________________________ Date: __________

BWCCMS Class:__________

Ancestor Lucy Spent Time in Trees


By Jennifer Viegas

australopithecus afarensis

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