When did modern humans first arrive in Asia? Skull pieces could hold clues.

By Charles Choi, LiveScience Contributor / August 20, 2012 Newfound pieces of human skull from "the Cave of the Monkeys" in Laos are the earliest skeletal evidence yet that humans once had an ancient, rapid migration to Asia. Anatomically modern humans first arose about 200,000 years ago in Africa. When and how our lineage then dispersed out of Africa has long proven controversial. Archaeological evidence and genetic data suggest that modern humans rapidly migrated out of Africa and into Southeast Asia by at least 60,000 years ago. However, complicating this notion is the notable absence of fossil evidence for modern human occupation in mainland Southeast Asia, likely because those bones do not survive well in the warm, tropical region. Now a partial skull from Tam Pa Ling, "the Cave of the Monkeys" in northern Laos helps fill in this mysterious gap in the fossil record. [See Photos of "Monkey Cave" Fossils] "Most surprising is the fact that we found anything at all," researcher Laura Lynn Shackelford, a paleoanthropologist at the University of Illinois, told LiveScience. "Most people didn't think we'd find anything in these caves, or even in the region where we're working in mainland Southeast Asia. But we're stubborn, gone where no one's really looked before, or at least in almost a century." Rough terrain, persistent scientists The fossils were discovered in 2009 in the limestone cave, which is located at the top of the Pa Hang Mountain 3,840 feet (1,170 meters) above sea level. "The cave is surrounded by lots of papaya and banana trees, so a troop of monkeys likes to come and forage there, therefore its name," Shackelford said. There were many challenges working in this area. "It's incredibly difficult to access the site — it's only 150 miles (240 kilometers) from the capital, but it takes us two days to drive there because of the rough terrain," Shackelford said. "We have to hike up the side of a cliff, do a bit of rock-climbing to get to the mouth of the cave, and then going in, we have to go 60 meters (200 ft) down a slope of wet clay. We also have to carry a generator and lights with us to see in the cave. We have to push pigs out of the way to get through the jungle — there are just pigs wandering around there." [Amazing Caves: Photos of Earth's Innards] "Every bit of clay has to be removed and taken back up by hand, trowel and bucket, so work is incredibly slow," she added. "We only go in the dry season in the winter, so we don't really have to deal with insects and snakes — well, we did have snakes fall into the pit while excavating. And in the cave, we've had more than our fair share of spiders and Oldest bones of modern humans No artifacts were found at the site, nor were signs of human occupation. "We think this fossil was outside with other fauna and flora, and during the rainy season, rain washed it into the cave," Shackelford said. "In subsequent seasons, more sediment washed into the cave and covered it." The shape of the bone and teeth is distinctly anatomically modern human, not like those of an extinct lineage such as the Neanderthals. A variety of dating techniques of the sediments surrounding the fossils suggests they are at least 46,000 to 51,000 years old, and direct dating of the bone suggests a maximum age of about 63,000 years. This makes these fossils the earliest skeletal evidence for anatomically modern humans east of the Middle East. These findings "change the thinking regarding modern human migration routes into Asia, that there were more routes of dispersal than previously thought," Shackelford said. "The typical thinking was that once modern humans hugged the coastline to go from India to Southeast Asia, they went southward into Indonesia and Australasia (the region comprising Australia, New Zealand and neighboring Pacific islands)," she explained. "We think they absolutely did that, but we're also suggesting other populations probably went north or northeast toward China, and some went through the mountains into mainland Southeast Asia, taking advantage of river systems. Beforehand, no one thought they would have gone into the mountains of Laos, Vietnam and Thailand." The researchers are now attempting to extract DNA from these fossils to see how related they may or may not be to later humans that once lived or currently live in the area. In the future, "the work we have is pretty boundless — there are literally thousands of limestone caves we can work on in this area to look for early modern humans," Shackelford said. "We can work here for the rest of our careers or lives and not see all the caves." The scientists detailed their findings online Aug. 20 in the journal the Proceedings of the National Academy of Sciences.

New theory says Big Bang was more like water freezing to ice

By Natalie Wolchover updated 8/21/2012 9:31:36 PM ET How did the universe begin? The Big Bang is traditionally envisioned as the moment when an infinitely dense bundle of energy suddenly burst outward, expanding in three spatial directions and gradually cooling down as it did so. Now, a team of physicists says the Big Bang should be modeled as a phase change: the moment when an amorphous, formless universe analogous to liquid water cooled and suddenly crystallized to form four-dimensional space-time, analogous to ice. In the new study, lead author James Quach and colleagues at the University of Melbourne in Australia say the hypothesis can be tested by looking for defects that would have formed in the structure of space-time when the universe crystallized. The universe is currently about 13.7 billion years old. "Think of the early universe as being like a liquid," Quach said in a statement. "Then as the universe cools, it 'crystallizes' into the three spatial and one time dimension that we see today. Theorized this way, as the universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice." If they exist, these cracks should be detectable, the researchers said, because light and other particles would bend or reflect off of them as they trek across the cosmos. [The History & Structure of the Universe (Infographic)] The notion that space and time are emergent properties that suddenly materialized out of an amorphous state was first put forth by physicists at Canada's Perimeter Institute in 2006. Called "quantum graphity," the theory holds that the four-dimensional geometry of space-time discovered by Albert Einstein is not fundamental; instead, space-time is more like a lattice constructed of discrete space-time building blocks, just like matter looks continuous, but is actually made of building blocks called atoms. Originally, at extremely high temperatures, the building blocks were like liquid water: they contained no structure, "representing a state with no space," the researchers wrote in their paper. At the moment of the Big Bang, when the temperature in the universe dropped to the space-time building blocks' "freezing point," they crystallized to form the four-dimensional lattice we observe today. The math describing the theory checks out, but "the challenge has been that these building blocks of space are very small, and so impossible to see directly," Quach explained. From the human vantage point, space-time looks smooth and continuous. However, while the building blocks themselves might be too small to detect, the physicists hope to observe the boundaries that would have formed as regions of crystallizing building blocks butted against one another at the time of the Big Bang, creating "cracks" in the universe. More work is needed to predict the average distance between the cracks — it isn't known whether they are microscopic, or light-years apart — in order to characterize their effects on particles. The research by Quach and his team is detailed in this month's edition of the journal Physical Review D.

Real Jurassic Park? Scientists to bring back woolly mammoth

by Michael Henrich

Doesn't anybody remember Jurassic Park?

Perhaps a certain group of Japanese and Russian scientists does not.

Thanks to the finding of well-preserved bone marrow in a woolly mammoth thigh bone recovered from Siberia, these scientists believe they can clone the long-extinct species and bring it back into existence, according to published reports.

The researchers plan to produce embryos with mammoth DNA by replacing the nuclei of egg cells from an elephant with those taken from the mammoth's marrow cells, the reports state.

Scientists from Russia's Sakha Republic's mammoth museum and Japan's Kinki University are launching the joint research project next year and hope to clone a woolly mammoth within five years.

Mammoths became extinct roughly 10,000 years ago.

Working For You

Now that I have entered cyberspace with a blog of sorts I wish to address those that will read this in the future and let you know that the preparation for next year's AP class has already begun.  Summer work is being refined and class objectives being developed. So as you read this at some later date you will hopefully have some appreciation for all of the work that goes into teaching!