tagged w/ Homo erectus
The discovery of million-year-old ash and charred bone in a South African cave suggests that human ancestors were using fire much earlier than previously thought.
By Eoin O'Carroll, Staff / April 3, 2012
Early humans harnessed fire as early as a million years ago, much earlier than previously thought, suggests evidence unearthed in a cave in South Africa.
Charred bones and ash discovered in South Africa's Wonderwerk Cave indicate the presence of frequent, controlled fires at the site one million years ago, writes an international team of scientists in a study published Monday in the Procedings of the National Academy of Sciences. If these findings are correct, they will overtake the earliest widely accepted evidence of early human use of fire, which was discovered in northern China and dates to 400,000 years ago.
Those fires, as well as the fires in Wonderwerk Cave, were probably burned by Homo erectus, a species thought to be a human ancestor or a relative of one. The cave itself is one of the oldest known sites of human habitation, with signs of early human settlement dating back two million years.
Unambiguous evidence for controlled fires is notoriously hard to come by. Outdoor sites are dubious, as they could have been natural blazes sparked by lightning. Even sites inside caves can be suspect, as ash and other burnt materials can be blown or washed in from elsewhere. The scientists working at Wonderwerk Cave examined the ash, which was found some 100 feet from the cave's entrance, under a microscope. The pieces of ash still had jagged edges, which would have likely been smoothed out had they been carried by wind or water from outside the cave.
According to Nature, the scientists even searched the site for bat feces, "because large piles of rotting guano can become hot enough to ignite spontaneously." But fortunately for the researchers, that layer of sediment was bat-excrement free.
As for the charred bones, the Los Angeles Times's Amina Khan notes that it's difficult to determine if a million-year-old bone appears charred because it was heated or because it has fossilized. So the researchers examined the bone fragments under a microscope.
Bones are filled with a mineral called hydroxylapatite, which gives them their strength. It forms in tiny plate-like crystals that slowly fuse together as an old bone is fossilized. When a bone is heated to high temperatures, however, the crystals change shape, growing into large needles rather than small plates.
The researchers found that the bone fragments indeed contained the large-needled crystals rather than the more conventional plate-like patterns. Based on their analysis, the bones had to have been heated to more than 750 degrees Fahrenheit.
The results caught [Boston University archaeologist and lead researcher Francesco] Berna by surprise. "I needed some time to convince myself — and then I needed some time to convince my colleagues," he said.
If it's hard to identify signs of a controlled fire, it's even trickier to determine if humans used it for cooking. After all, the bones could have simply been tossed into the fire after being stripped of raw meat.
And although the depth of the sediment suggests that fires burned on the same spot over and over again, the researchers found no signs of a stone hearth – a sure sign of deliberate fire – anywhere near the spot.
All of this points to the important distinction between using fire and mastering it. Nature quotes Wil Roebroeks, an archaeologist at Leiden University in the Netherlands.
“I think it likely that humans were using fire at this site, but I don’t think that this means these hominins were regular fire users. For a claim like that to be made, we would need to see hearths and fire places, and we do not,” he says. “If we were to discover many more fire sites at this time in history and find that natural cave fires look distinctly different, that would support an early-cooking hypothesis, but we are not there yet."The discovery of million-year-old ash and charred bone in a South African cave... more
In the 2000 years since his mission of compassionate aid to the poor and confrontation of the rich, our world has been transformed but remains sadly unequal. To the wealthy, the living guru Jesus said “sell what you have then distribute the money to the needy and follow me”. A tall order in a gruesome time when the only social safety net was the one you caught your fish with. In ancient Judea, prices were so high Jesus and his followers may have been supported by donations from viewers like you.In the 2000 years since his mission of compassionate aid to the poor and confrontation... more
The New York Times...
December 26, 2011
The Hormone Surge of Middle Childhood
By NATALIE ANGIER
VIEWED superficially, the part of youth that the psychologist Jean Piaget called middle childhood looks tame and uneventful, a quiet patch of road on the otherwise hairpin highway to adulthood.
Said to begin around 5 or 6, when toddlerhood has ended and even the most protractedly breast-fed children have been weaned, and to end when the teen years commence, middle childhood certainly lacks the physical flamboyance of the epochs fore and aft: no gotcha cuteness of babydom, no secondary sexual billboards of pubescence.
Yet as new findings from neuroscience, evolutionary biology, paleontology and anthropology make clear, middle childhood is anything but a bland placeholder. To the contrary, it is a time of great cognitive creativity and ambition, when the brain has pretty much reached its adult size and can focus on threading together its private intranet service — on forging, organizing, amplifying and annotating the tens of billions of synaptic connections that allow brain cells and brain domains to communicate.
Subsidizing the deft frenzy of brain maturation is a distinctive endocrinological event called adrenarche (a-DREN-ar-kee), when the adrenal glands that sit like tricornered hats atop the kidneys begin pumping out powerful hormones known to affect the brain, most notably the androgen dihydroepiandrosterone, or DHEA. Researchers have only begun to understand adrenarche in any detail, but they see it as a signature feature of middle childhood every bit as important as the more familiar gonadal reveille that follows a few years later.
Middle childhood is when the parts of the brain most closely associated with being human finally come online: our ability to control our impulses, to reason, to focus, to plan for the future.
Young children may know something about death and see monsters lurking under every bed, but only in middle childhood is the brain capable of practicing so-called terror management, of accepting one’s inevitable mortality or at least pushing thoughts of it aside.
Other researchers studying the fossil record suggest that a prolonged middle childhood is a fairly recent development in human evolution, a luxury of unfolding that our cousins the Neanderthals did not seem to share. Still others have analyzed attitudes toward middle childhood historically and cross-culturally. The researchers have found that virtually every group examined recognizes middle childhood as a developmental watershed, when children emerge from the shadows of dependency and start taking their place in the wider world.
Much of the new work on middle childhood was described in a recent special issue of the journal Human Nature. As a research topic, “middle childhood has been very much overlooked until recently,” said David Lancy, an anthropologist at Utah State University and a contributor to the special issue. “Which makes it all the more exciting to participate in the field today.”
The anatomy of middle childhood can be subtle. Adult teeth start growing in, allowing children to diversify their diet beyond the mashed potatoes and parentally dissected Salisbury steak stage. The growth of the skeleton, by contrast, slows from the vertiginous pace of early childhood, and though there is a mild growth spurt at age 6 or 7, as well as a bit of chubbying up during the so-called adiposity rebound of middle childhood, much of the remaining skeletal growth awaits the superspurt of puberty.
“Adulthood is defined by being skeletally as well as sexually mature,” said Jennifer Thompson of the University of Nevada, Las Vegas. “A girl may have her first period at 11 or 12, but her pelvis doesn’t finish growing until about the age of 18.”
The 18-year time frame of human juvenility far exceeds that seen in any other great ape, Dr. Thompson said. Chimpanzees, for example, are fully formed by age 12. With her colleague Andrew J. Nelson of the University of Western Ontario, Dr. Thompson analyzed fossil specimens from Neanderthals, Homo erectus and other early hominids, and concluded that their growth pattern was more like that of a chimpanzee than a modern human: By age 12 or 14, they had reached adult size.
.The New York Times...
December 26, 2011
The Hormone Surge of Middle... more
A “missing link” between humans and their apelike ancestors has been discovered.
By Richard Gray
03 Apr 2010
The new species of hominid, the evolutionary branch of primates that includes humans, is to be revealed when the two-million-year-old skeleton of a child is unveiled this week
For the Full Story..The “Missing Link” Between Man and Apes Found, Complete Skeleton. Photos – Video…http://ctpatriot1970.wordpress.com/2010/04/03/the-missing-link-between-man-and-apes-found-complete-skeleton-photos-video/
Scientists believe the almost-complete fossilised skeleton belonged to a previously-unknown type of early human ancestor that may have been a intermediate stage as ape-men evolved into the first species of advanced humans, Homo habilis.A “missing link” between humans and their apelike ancestors has been... more
A new and more accurate dating method shows Peking Man may be 200,000 years older than what experts previously thought, researchers in China said.
Between 1921 and 1966, archaeologists working at the site unearthed tens of thousands of stone tools and hundreds of fragmentary remains from about 40 early humans.
Palaeontologists later assigned these members of the human lineage to the species Homo erectus.A new and more accurate dating method shows Peking Man may be 200,000 years older than... more