Discover Magazine | Early Language

Impatient Futurist: The Sperm Crisis: A Tough Nut to Crack

Tue, 08 Nov 2011 14:05:00 -0500

"If we keep fixing the problem in 10,000 years no men
will be producing sperm," says urological surgeon Sherman Silber.

I refuse to age gracefully. That is to say, I refuse to age at all, other than for accounting purposes and to get discounts, which seem to kick in at movie theaters and hotels at 62—six years away. This applies to my sperm as well. I fully intend to maintain excellent spermatic health into my nineties, at least. It’s not just that my hard-wired imperative to perpetuate my genes is driving me to keep my options open; I’m not claiming my genes are anything special. It’s more the principle of the thing. Allowing any part of my body to fade just because I don’t strictly need it anymore is a slippery slope.

Admittedly, my motivation may smack of vanity, but in the case of sperm we all have good reason for concern. While the evidence is a bit inconsistent, some medical researchers insist that human sperm are going downhill and have been doing so for at least a century. Men appear to be making less sperm on average, several studies report, and what is made tends to be subfertile, which the World Health Organization describes as sperm that swim poorly, take on a funny shape, fail to reach concentrations higher than 15 million per milliliter, or otherwise struggle to impregnate an egg.

“We’re producing pretty poor sperm compared with those of primates and other mammals,” says Gary Cherr, a reproductive toxicologist at the University of California, Davis. “Even in the most fertile men, there are quality issues.” A recent European report found that one in five young men has underachieving sperm...

Egypt's Ancient Fleet: Lost for Thousands of Years, Discovered in a Desolate Cave

Tue, 06 Sep 2011 14:05:00 -0400

The scenes carved into a wall of the ancient Egyptian temple at Deir el-Bahri tell of a remarkable sea voyage. A fleet of cargo ships bearing exotic plants, animals, and precious incense navigates through high-crested waves on a journey from a mysterious land known as Punt or “the Land of God.” The carvings were commissioned by Hatshepsut, ancient Egypt’s greatest female pharaoh, who controlled Egypt for more than two decades in the 15th century B.C. She ruled some 2 million people and oversaw one of most powerful empires of the ancient world.

The exact meaning of the detailed carvings has divided Egyptologists ever since they were discovered in the mid-19th century. “Some people have argued that Punt was inland and not on the sea, or a fictitious place altogether,”  Oxford Egyptologist John Baines says. Recently, however, a series of remarkable discoveries on a desolate stretch of the Red Sea coast has settled the debate, proving once and for all that the masterful building skills of the ancient Egyptians applied to oceangoing ships as well as to pyramids.

Archaeologists from Italy, the United States, and Egypt excavating a dried-up lagoon known as Mersa Gawasis have unearthed traces of an ancient harbor that once launched early voyages like Hatshepsut’s onto the open ocean. Some of the site’s most evocative evidence for the ancient Egyptians’ seafaring prowess is concealed behind a modern steel door set into a cliff just 700 feet or so from the Red Sea shore. Inside is a man-made cave about 70 feet deep. Lightbulbs powered by a gas generator thrumming just outside illuminate pockets of work: Here, an excavator carefully brushes sand and debris away from a 3,800-year-old reed mat; there, conservation experts photograph wood planks, chemically preserve them, and wrap them for storage...

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Image: A relief at the temple of the female pharaoh Hatshepsut in Luxor, Egypt, carved ca. 1480 B.B., shows a merchant ship on a trading expedition. Vessel artifacts match this depiction. Courtesy of Stephane Begoin.

Homo Sapiens, Meet Your New Astounding Family

Thu, 28 Jul 2011 09:55:00 -0400

A single, unforgettable image comes to mind when we ponder human origins: a crouching ape slowly standing and morphing into a tall, erect human male poised to conquer every bit of habitable land on this planet. We walk this earth—we, this unparalleled experiment in evolution—reflexively assuming we are the crown of creation. Certainly we are rare and strange: As biological anthropologist Owen Lovejoy of Kent State University says, “The chances that a creature like us will ever happen again are so small that I can’t even measure them.”

But that ascent-of-man picture is looking as dated as the flat earth. A series of scientific and technological breakthroughs have altered much of our fundamental understanding of human evolution. In the new view, the path to Homo sapiens was amazingly dilatory and indirect. Along the way, our planet witnessed many variations on the human form, multiple migrations out of Africa, interspecies trysts, and extinctions that ultimately wiped out all hominid species except one. “Human evolution used to seem simple and linear,” says paleoanthropologist William Jungers of the State University of New York at Stony Brook. “Now, you look at almost any time slice and you see diversity. We may be special and we may be lucky, but we’re far from the only human experiment.”

Unexpected fossil finds keep showing us an ever-expanding variety of human and prehuman species. Probably the most stunning of these recent discoveries is Ardipithecus ramidus, an ancestor who displayed a fantastical mosaic of ape and human traits.  A. ramidus apparently climbed trees but also walked upright some 4.4 million years ago—more than half a million years before the long-accepted origin of bipedalism.

As anthropologists use all the latest tools—genomics, computer analysis, and increasingly sophisticated imaging—to extract deep secrets from the latest fossil finds, they are replacing the “ascent of man” with a captivating new picture of the human family. It edges us decisively closer to understanding not only where we came from but also what made us so much more successful than other, superficially similar primates. “Our relatives, the gorillas and chimpanzees, are still living in the forest in a little piece of West Africa,” Lovejoy says, “and orangutans have survived on two islands in Southeast Asia, but we have evolved rapidly and are everywhere.”

Why, after so many human experiments, are we the only ones left standing?...

Image: Ardipithecus ramidus, Ardi. Courtesy of Wikipedia/T. Michael Keesey

Monkeys  & Morality

Mon, 20 Jun 2011 13:15:00 -0400

The academic community quaked last August when Harvard confirmed that it had found Marc Hauser, a cognitive scientist at the university, “solely responsible” for eight cases of scientific misconduct. Hauser was a rising star whose studies of primate behavior seemed to show that the foundations of language and morality are hardwired into the brains of humans and our kin. But a document provided to The Chronicle of Higher Education indicates that Hauser’s lab workers observed huge discrepancies between his descriptions of monkey behavior and the experimental results captured on video...

5 Questions for the Woman Who Found Somalia's History

Sun, 19 Jun 2011 10:00:00 -0400

When Sada Mire was just 12, her father, a Somali police official, was executed by the country’s brutal Barre regime, which saw him as a political threat. In 1991 she fled Somalia, reuniting with family in Sweden and eventually pursuing graduate studies in England. But while working on her Ph.D. in archaeology from University College London, Mire’s academic interests drew her back to Africa. She returned to her homeland for the first time in 16 years to carry out research in Somaliland—a relatively peaceful, self-declared state in the northwestern part of Somalia—where she discovered several prehistoric rock art sites. In 2007 she was named Somaliland’s Director of Antiquities. Mire hopes to spur interest in the region’s cultural heritage, using the past to foster peace and understanding among her people today...

Photo: Graham Trott; grooming: Claire Hanson

How Societies Slowly Rise—and Suddenly Fall

Thu, 16 Jun 2011 14:25:00 -0400

Societies grow through slow, incremental change, but their collapse can be sudden and dramatic. That is one intriguing lesson from a recent study of diverse cultures across Southeast Asia and the Pacific Islands by University College London anthropologist Tom Currie. The research aims to settle a major anthropological debate over whether political systems develop the same way regardless of culture; the results  suggest that some aspects of political development are in fact universal...

It took a sophisticated well-organized society to produce Prambanan, Java's largest temple complex.

iStockphoto

Bronze Age Brain Surgeons

Wed, 08 Jun 2011 22:10:00 -0400

You might shudder at the mere thought of ancient brain surgery, but recent studies of the practice at Bronze Age sites in Turkey suggest that early neurosurgeons were surprisingly precise and that a majority of their patients may have survived...

Image of the 4,400-year-old skull of an early neurosurgery patient, courtesy of the Ikiztepe archive

Lost Civilizations Found in the Jungle

Tue, 10 May 2011 11:00:00 -0400

Image: iStockphoto

For generations, researchers dismissed the Amazon as a cultural desert, a jungle terrain too treacherous to support any civilization more sophisticated than nomadic tribes. But in recent years archaeologists have uncovered evidence of ancient, densely populated settlements throughout the basin, hinting at societies far larger and more advanced than previously thought.

Some of the most eye-opening new research comes from the western Amazon, where archaeologist Denise Schaan of the Federal University of Pará in Brazil has mapped clusters of mysterious land sculptures dug between 700 and 2,000 years ago...

If Modern Humans Are So Smart, Why Are Our Brains Shrinking?

Thu, 20 Jan 2011 13:05:00 -0500

John Hawks is in the middle of explaining his research on human evolution when he drops a bombshell. Running down a list of changes that have occurred in our skeleton and skull since the Stone Age, the University of Wisconsin anthropologist nonchalantly adds, “And it’s also clear the brain has been shrinking.”

“Shrinking?” I ask. “I thought it was getting larger.” The whole ascent-of-man thing.

“That was true for 2 million years of our evolution,” Hawks says. “But there has been a reversal.”

He rattles off some dismaying numbers: Over the past 20,000 years, the average volume of the human male brain has decreased from 1,500 cubic centimeters to 1,350 cc, losing a chunk the size of a tennis ball. The female brain has shrunk by about the same proportion. “I’d call that major downsizing in an evolutionary eyeblink,” he says. “This happened in China, Europe, Africa—everywhere we look.” If our brain keeps dwindling at that rate over the next 20,000 years, it will start to approach the size of that found in Homo erectus, a relative that lived half a million years ago and had a brain volume of only 1,100 cc. Possibly owing to said shrinkage, it takes me a while to catch on. “Are you saying we’re getting dumber?” I ask.

Hawks, a bearish man with rounded features and a jovial disposition, looks at me with an amused expression. “It certainly gives you a different perspective on the advantage of a big brain,” he says.

After meeting with Hawks, I call around to other experts to see if they know about our shrinking brain. Geneticists who study the evolution of the human genome seem as surprised as I am (typical response: “No kidding!”), which makes me wonder if I’m the world’s most gullible person. But no, Hawks is not pulling my leg. As I soon discover, only a tight-knit circle of paleontologists seem to be in on the secret, and even they seem a bit muddled about the matter. Their theories as to why the human brain is shrinking are all over the map...

The Alien Seekers of SETI Are Just Getting Started

Mon, 03 Jan 2011 11:40:00 -0500

For the uninitiated, the name “SETI Institute” may conjure up sleek glass buildings, mammoth radio dishes, and creased-brow researchers rushing about waving enigmatic printouts. After all, SETI—the Search for Extraterrestrial Intelligence—is one of the most far-reaching and controversial projects in science. The idea that the universe might contain civilizations other than our own probably helped get Giordano Bruno burned at the stake in 1600. It sparked a famous 19th-century newspaper hoax in which astronomers were said to have found a society of “man-bats” on the moon. It motivated Percival Lowell’s writings about canals on Mars at the turn of the last century, and it inspired Orson Welles’s infamous “War of the Worlds” radio broadcast in 1938, which sent hundreds of thousands of listeners into a panic over a fictional Martian invasion they thought was real.

As the culmination of that grand history, the SETI Institute deserves an equally grand location, but the reality is quite a bit more modest. The institute occupies a single floor in an office park across the street from a residential district in suburban Mountain View, California, not far from a printing company and a shop called Fun House Theatrical Costumes. “This is the biggest such operation in the world,” says Seth Shostak, a senior scientist with the institute, “and there are just 10 or 12 of us here doing SETI. It’s not legions of lab-coated scientists with clipboards. I wish it were.”

At first blush, the organization’s results might seem equally disappointing. This year marks the 50th anniversary of the first modern SETI search: It was in April 1960 that astronomer Frank Drake pointed a radio telescope at the nearby star Tau Ceti and began listening for the telltale ping of an alien communication. Instead he just heard static, and in the half-century since, the silence has been complete.

So is Shostak discouraged by all the dead air? “Heck no,” he says, not missing a beat. Despite five decades of null results and chronic underfunding, he and his colleagues are more upbeat than ever. He ticks off some reasons: Dramatic improvements in technology are speeding up the search. Recent star surveys indicate that planetary systems—very likely including many Earth-like planets—are common throughout the Milky Way and the rest of the universe. And the latest explorations of our own planet demonstrate that life can exist in a much wider range of environments than anyone previously thought.

As a result, many SETI scientists regard the last 50 years as just a learning process. “Imagine,” says Jill Tarter, director of the Center for SETI Research at the SETI Institute and one of the stalwarts in the field, “that you didn’t know whether there were any fish in Earth’s oceans. So you go out and dip a single eight-ounce glass in the water. You might find one. But if the glass came up empty, I don’t think your first response would be ‘There are no fish’”...

Discover Magazine | Early Language

Top 100 Stories of 2011: #59: The Mismeasure of Stephen Jay Gould

Top 100 Stories of 2011: #80: Neanderthal DNA Boosts Your Immune System

Impatient Futurist: The Sperm Crisis: A Tough Nut to Crack

Egypt's Ancient Fleet: Lost for Thousands of Years, Discovered in a Desolate Cave

Homo Sapiens, Meet Your New Astounding Family

Monkeys  & Morality

5 Questions for the Woman Who Found Somalia's History

How Societies Slowly Rise—and Suddenly Fall

Bronze Age Brain Surgeons

Lost Civilizations Found in the Jungle

Top 100 Stories of 2010: #5: Family Genomics Links DNA to Disease

If Modern Humans Are So Smart, Why Are Our Brains Shrinking?

The Alien Seekers of SETI Are Just Getting Started

Top 100 Stories of 2010: #53: Medical Secrets Inside a 2,000-Year-Old Pill

Top 100 Stories of 2010: #34: Our Jumbled Ancestor

Top 100 Stories of 2010: #39: Microbes Are Key to a Happy Gut

Top 100 Stories of 2010: #75: Social Life Begins in the Womb

Top 100 Stories of 2010: #72: Stone-Age Romeos and Juliets

Top 100 Stories of 2010: #45: Pinkie Pokes Holes in Human Evolution

Top 100 Stories of 2010: #29: Ardi Continues to Shake the Human Family Tree

Top 100 Stories of 2010: #22: Hair DNA Documents Forgotten Migration

Top 100 Stories of 2010: #81: Melting Ice Exposes the Past

Top 100 Stories of 2010: #51: Computer Rosetta Stone

Top 100 Stories of 2010: #89: Chinese Pompeii Unearthed

Top 100 Stories of 2010: #48: The Science of Chivalry

Discover Magazine | Early Language

Top 100 Stories of 2011: #59: The Mismeasure of Stephen Jay Gould

Top 100 Stories of 2011: #80: Neanderthal DNA Boosts Your Immune System

Impatient Futurist: The Sperm Crisis: A Tough Nut to Crack

Egypt's Ancient Fleet: Lost for Thousands of Years, Discovered in a Desolate Cave

Homo Sapiens, Meet Your New Astounding Family

Monkeys & Morality

5 Questions for the Woman Who Found Somalia's History

How Societies Slowly Rise—and Suddenly Fall

Bronze Age Brain Surgeons

Lost Civilizations Found in the Jungle

Top 100 Stories of 2010: #5: Family Genomics Links DNA to Disease

If Modern Humans Are So Smart, Why Are Our Brains Shrinking?

The Alien Seekers of SETI Are Just Getting Started

Top 100 Stories of 2010: #53: Medical Secrets Inside a 2,000-Year-Old Pill

Top 100 Stories of 2010: #34: Our Jumbled Ancestor

Top 100 Stories of 2010: #39: Microbes Are Key to a Happy Gut

Top 100 Stories of 2010: #75: Social Life Begins in the Womb

Top 100 Stories of 2010: #72: Stone-Age Romeos and Juliets

Top 100 Stories of 2010: #45: Pinkie Pokes Holes in Human Evolution

Top 100 Stories of 2010: #29: Ardi Continues to Shake the Human Family Tree

Top 100 Stories of 2010: #22: Hair DNA Documents Forgotten Migration

Top 100 Stories of 2010: #81: Melting Ice Exposes the Past

Top 100 Stories of 2010: #51: Computer Rosetta Stone

Top 100 Stories of 2010: #89: Chinese Pompeii Unearthed

Top 100 Stories of 2010: #48: The Science of Chivalry

Monkeys  & Morality