Ocean Impact Map Reveals Human Reach Global

Ocean Impact Map Reveals Human Reach Global

As vast as the oceans are, almost no waters remain untouched by human activities

 
HUMAN IMPACT: This map represents the first effort to pinpoint all the ways human activities impact the oceans, and where those impacts are the worst.

Fishing, fertilizer runoff, pollution, shipping, climate change—these are just a few of the ways that human activities influence the oceans that cover 70 percent of Earth's surface. And in all that vastness—139 million square miles (360 million square kilometers)—less than 4 percent remains unaffected, and more than a third has suffered serious human impacts, according to a new map published in Science.

Marine ecologist Ben Halpern of the University of California, Santa Barbara's National Center for Ecological Analysis and Synthesis and an international team of colleagues first listed 17 ways humans affect the oceans and then mapped each of them. By overlaying each impact on top of one another, the ecologists created a "current state of affairs for the oceans," Halpern says. "I was really surprised that there is no single spot on the planet that isn't being affected by at least one of these factors."

The map offers a guide to the most impacted areas, not surprisingly located where the most human activities occur, such as in waters adjacent to cities on the coasts of the North Sea, Mediterranean, Persian Gulf and South China Sea as well as off North America's eastern seaboard, among others. Yet, the map is crude, Halpern says. "Aquaculture, recreational fishing, sediment input from rivers that are being blocked by dams, atmospheric pollution—we know these are problems or potential problems and we wanted to include them but we just couldn't find the data," he notes. "Our results are almost certainly conservative."

Coral reefs, among other ecosystems, are suffering mightily at the hands of humans. It remains unclear, though, whether the host of impacts they face will compound themselves or cancel each other out, says marine ecologist John Bruno of the University of North Carolina at Chapel Hill, who also contributed to the map.

Shallow seas with muck at the bottom and the deepest parts of the ocean proved the least affected so far, due to the resilience of those ecosystems or a lack of good knowledge. "The deep water is such a vast, relatively unexplored area, we just don't know what kinds of impacts we're having on those ecosystems," Halpern says. "We spend trillions of dollars going to the moon and we don't really know what's going on in our own oceans yet."

Although the Bering Sea is an area of strong human influence, the polar seas are among the few watery stretches that show little sign of humanity's impact—yet. As these areas continue to warm under climate change, however, dwindling sea ice may open up new areas to fishing and other forms of human activity, the researchers warn.

But there are reasons for hope. The Marine Conservation Alliance (MCA)—a fishing industry group based in Juneau, Alaska—has called for a ban on fishing north of the Bering Strait, according to MCA executive director David Benton. "Let's shut this puppy down until we understand the effects," he says. "We don't want to be part of the problem for polar bears" and other Arctic animals.

And the tiny Pacific nation of Kiribati—just 313 square miles (810 square kilometers) of atolls—has decided to protect more than 10 percent of its territorial waters—158,000 square miles (410,500 square kilometers), an area roughly the size of California—as the largest marine reserve in the world.

These kinds of efforts are exactly what the mapmakers hope to inspire. By revealing areas where mankind does its worst, the map also divulges where mankind can do best in limiting its impact. "It's definitely serving as a wake-up call to really start paying more attention to what we're doing to the oceans," Halpern says. "I hope people step up to the plate, knowing they have the opportunity to make a difference."

 

"Junk" RNA May Have Played Role in Vertebrate Evolution

"Junk" RNA May Have Played Role in Vertebrate Evolution

New study says tiny snippets of RNA co-evolved with vertebrates, likely accounting for the new organisms' complexity

 
MICRORNA INSIDE: The lamprey, the jawless fish that represents one of the earliest vertebrates, has several more microRNAs than the proto-vertebrate sea squirt.

Genetic material once dismissed as mere "junk" may in fact be responsible to the evolution of simple invertebrates into more complex organisms sporting backbones, according to a new study.

Tiny snippets of the genome known as microRNA were long thought to be genomic refuse because they were transcribed from so-called "junk DNA," sections of the genome that do not carry information for making proteins responsible for various cellular functions. Evidence has been building since 1993, however, that microRNA is anything but genetic bric-a-brac. Quite the contrary, scientists say that it actually plays a crucial role in switching protein-coding genes on or off and regulating the amount of protein those genes produce.

Now, researchers from Dartmouth College in Hanover, N.H., and the University of Bristol in England report in Proceedings of the National Academy of Sciences USA that these tiny genetic segments could be responsible for the evolution of animals with backbones, noting that they found a surfeit of microRNA in the genomes of the earliest vertebrates, such as lampreys (jawless fish), when compared with invertebrates like sea squirts.

"There's this dramatic increase in microRNAs that were fixed in the genome of vertebrates and were rarely secondarily lost," says study co-author Kevin Peterson, an associate professor of biological sciences at Dartmouth. "If a human has a microRNA that's also found in zebra fish, we [typically] find it in lamprey but we don't find it in any invertebrate," implying that that piece of genetic material is unique to vertebrates

Peterson says that scientists previously believed that the jump in complexity from invertebrates to vertebrates was due to genome-duplication events, during which large swaths of new genetic material were made (by some unknown mechanism) that randomly mutated and ultimately evolved into new species. In 2005 some researchers believed they had uncovered compelling evidence that two of these so-called duplication events had taken place when they compared the genomes of vertebrates with those of sea squirts, and between to vertebrate lineages: bony fish (lungfish and Atlantic blue marlin) and sharks.

But the Human Genome Project, completed in 2003, punched holes in their theory. The reason: if two duplication events had occurred, scientists would expect the resulting vertebrates to have four times as many genes as their spineless predecessors. Yet, among other things revealed by the genome project, was that humans have between 20,000 and 25,000 genes, which is less than two times the number carried by mere fruit flies.

"Given that most of the genes [from the genome-duplication events] were lost," Peterson says, "we thought maybe it's a red herring in thinking about the origin of vertebrate complexity." So, Peterson and his colleagues instead turned their focus to microRNA.

Beginning with mammals, like humans and mice, the team worked backward through time scanning genomes for microRNAidentified by its characteristic hairpin shape and 21- to 23-nucleotide (structural unit) length. The researchers compared shark, lamprey and sea squirt genomes and found much more microRNA in lampreys than in sea squirts. (Sharks, of course, are more complex than lampreys, and thereby also had more microRNA than the lowly squirts.) More interesting, this expansion of microRNA from the sea squirt to the lamprey predates the genome-duplication events that were thought to have created vertebrates.

The scientists also found that the majority of new microRNA was centered around genes responsible for the development of organs unique to vertebrates, such as the liver, pancreas and brain, says co-author Philip Donoghue, a senior lecturer in Bristol University's Department of Earth Sciences. "Therefore," he adds, "the origin of vertebrates and the origin of these genes is no coincidence."

Peter Stadler, a professor of bioinformatics at the University of Leipzig in Germany, believes it is plausible that microRNAs, given their known role in gene regulation, could be responsible for the complex changes that took place between invertebrates and vertebrates. He is, however, not sure that they acted alone. "I would be reluctant to rely solely on gene phylogenies of a small number of microRNAs, given that there is still no definitive information on the relative timing of the lampreygnathostome [vertebrates with jaws] split and the two rounds of vertebrate-specific genome duplications," he says. "With more genomes becoming available for basal chordates [proto-vertebrates, like the sea squirt], it will be very interesting to elucidate in detail the interplay of genome duplications, protein innovations and restructuring of the microRNA inventory."

Scientists see promise in new way to fight viruses

Scientists see promise in new way to fight viruses

Scientists have discovered a promising new method to fight a range of diseases by boosting the body's natural defenses against viruses.

Mauro Costa-Mattioli of McGill University in Montreal, who helped lead the research published on Wednesday in the journal Nature, expressed hope that the results achieved in mice might lead to new antiviral drugs for people.

The researchers inactivated two genes in mice that repress production of interferon, a protein that serves as a cell's first line of defense against viruses. The mice produced much higher levels of interferon, which had the effect of preventing the viruses from reproducing.

The technique made the mice and their cells resistant to infection by the influenza virus and a handful of other viruses, Costa-Mattioli's team said. The mice did not appear to experience any negative consequences from the augmented interferon production.

The process of inactivating genes -- known as "knocking out" genes -- cannot currently be done in people, but the scientists said they hope that drugs can be designed to affect the two genes in order to protect people from viral infection.

"Hopefully we will mimic the results we got genetically with pharmacology," Costa-Mattioli said in a telephone interview. "I think it's going to be an important step forward."

Viral infections are among the most common diseases, ranging from influenza to AIDS, and can be very difficult to fight.

Viruses enter living cells and exploit their reproductive machinery to sustain and replicate themselves. Interferon suppresses this viral propagation.

"People have been worried for years about potential new viral pandemics, such as avian influenzas," Nahum Sonenberg, a Howard Hughes Medical Institute international scholar at McGill who worked on the study, said in a statement. "If we might now have the means to develop a new therapy to fight flu, the potential is huge."

The researchers said the method holds the potential to combat a range of viral diseases.

"We hope that we will also be able to stop other viruses like Ebola and others, based on what we have so far," Costa-Mattioli said. "I think it's going to block a few of them or a majority of them, but I cannot promise. I would be very naive to say we've saved the world."

Study catches picture of deadly cancer enzyme

Study catches picture of deadly cancer enzyme

Scientists have captured an image of an enzyme key to the progression of the deadliest cancers and said on Wednesday their findings may lead to new therapies against not only cancer, but HIV and diabetes too.

They caught in the act a mutant version of an enzyme called p300/CBP, which is involved in pancreatic, colon, and lung cancers, thyroid cancer and some leukemias.

The image of this structure might provide a way to design a drug that blocks it, and perhaps stop some tumor-causing mutations.

The same structure is involved in infection with the AIDS virus and diabetes, as well, said Dr. Philip Cole, a professor and director of pharmacology and molecular sciences at Johns Hopkins University in Baltimore.

"If we could wipe all those, we would have a lot fewer deaths," Cole said in a telephone interview.

Writing in the journal Nature, Cole and colleagues at the Wistar Institute and the University of Pennsylvania said the enzyme acted in a hit-and-run fashion, working so quickly it had been difficult to image it. Without an image, it is hard to know precisely how to counter its effects.

The enzyme p300/CBP is a transcription factor, one of a large family of enzymes that unwrap DNA from around other proteins known as histones.

Cole said a delicate balance of p300 was needed, as either too much or too little can both lead to cancer.

"There is definitely some evidence that blocking this enzyme in the host may make it harder for HIV to be pathogenic," Cole added.

His lab has a compound that interferes with p300 but now it may be possible to make a better one, he said.

"We've had a chemical inhibitor of p300 for about nine years now, but without the structure, we had no idea how it was working or, more importantly, how to improve on it," he said.

"We're still in our infancy of understanding how to go after cancer," Cole added. "But this definitely is a step in the right direction."

The study may also help explain how some natural products can affect cancer. Curcumin, the compound that makes the spice turmeric yellow, has been shown in studies to interfere with p300/CBP.

How Writing Changed the World

How Writing Changed the World

 
This cuneiform text dates back to the 6th year of prince Lugalanda who ruled about 2370 B.C. in southern Mesopotamia. It is an administrative document concerning deliveries of three sorts of beer to different recipients (to the palace and to a temple for offerings) and gives the exact quantities of barley and other ingredients used in brewing.

Humans had been speaking for a couple hundred thousand years before they got the inspiration or nerve to mark their ideas down for posterity.

But when a Mesopotamian people called the Sumerians finally did scratch out a few bookkeeping symbols on clay tablets 5,000 years ago, they unknowingly started a whole new era in history we call, well ... history.

The presence of written sources denotes the technical dividing line between what scholars classify as prehistory versus what they call history, which starts at different times depending on what part of the world you're studying.

In most places, writing started about the same time ancient civilizations emerged from hunter-gatherer communities, probably as a way to keep track of the new concept of "property," such as animals, grain supplies or land.

By 3000 B.C. in Mesopotamia (present-day Iraq), and then soon after in Egypt, and by 1500 B.C. in China, people were scribbling, sketching and telling their world about their culture in a very permanent way.

When memory failed

When ancient Mesopotamians started settling down onto farms surrounding the first cities, life became a bit more complicated. Agriculture required expertise and detailed recordkeeping, two elements that led directly to the invention of writing, historians say.

The first examples of writing were pictograms used by temple officials to keep track of the inflows and outflows of the city's grain and animal stores which, in the bigger Sumerian urban centers such as Ur, were big enough to make counting by memory unreliable.

Officials began using standardized symbols — rather than, say, an actual picture of a goat — to represent commodities, scratched into soft clay tablets with a pointed reed that had been cut into a wedge shape. Archaeologists call this first writing "cuneiform," from the Latin "cuneus," meaning wedge.

The system developed quickly to incorporate signs that represented sounds, and soon all of Mesopotamia was taking notes, making to-do lists and (presumably) writing love letters.

Egyptian writing — the famous hieroglyphics — developed independently not long thereafter, under similar circumstances, historians think.

A few thousand years later, as variations on the two systems spread throughout the region, the entire ancient world had writing schemes that vastly improved the efficiency of economies, the accountability of governments and, maybe most importantly to us, our understanding of the past.

Literacy a privilege

Reading and writing in ancient times wasn't for the masses, however. Daily life in Mesopotamia and Egypt was time-consuming, and so writing became a specialized profession, usually for members of the elite class. The highly-regarded scribes of ancient Mesopotamia were even depicted in art wearing cuneiform writing implements (a bit like a set of chopsticks) in their belts as a mark of their importance.

Literacy remained a privilege of aristocratic males in most societies all the way until the 19th-century, when public education became more widespread around the world.

That means that while the historical period is exponentially better understood than the experiences of humans before writing was invented, written accounts are largely about the experiences of the upper classes, historians say.

About one in five people today, concentrated mostly in Third World nations, are illiterate.