A New Year’s Diet: Mind Control

By: | January 6, 2011

First week of January. Like everybody else in America, I’m on a diet.

I’ve tried lots of diets over the years, and no matter how simple the particular rules — Fat is bad: stick to salads, whole grains and fruit! No no no, fat is good: lay off carbs, and eat lots of meat. Count calories. Count carbs. Are you getting enough fiber? Eat cookies all day! — following them is never easy.

Eating is what neuroscientists call a complex behavior. It’s not reflexive, like a knee jerk or sneeze, but rather depends on lots of brain systems. Real, painful hunger, of course, triggers eating. But so can the smell of bacon, even if you’ve already had breakfast. If you’re starving on a lettuce diet, good old willpower can (I’ve heard) override your urges to eat. And this complexity isn’t just a human thing. For lots of animals, feeding motivations can change with body temperature, sleep cycles and mating opportunities. Dozens of brain regions and hundreds of different kinds of brain cells have been tied to eating.

Which is why this study I’m about to gush about is so (mind the pun) startling. Scott Sternson‘s team from Janelia Farm compelled mice to voraciously eat by switching on just one type of neuron in their brains. Perhaps more provocative, the researchers got mice to completely stop eating by activating a different type of neuron.
Continue reading →

A Pox on Your Hand

By: | January 4, 2011

On a crisp fall day in November 2008, a wildlife biologist killed a deer in Eastern Virginia. He slit the carcass open from breast to tail and removed the animal’s internal organs. Hunting knives are very sharp. And, in the process of field dressing the deer, he nicked his knuckle. I imagine he didn’t think much of it at the time. But the cut did not heal. Two weeks later he had a painful bump where the wound had been. By mid-December, the bump had become an angry purple nodule. Not surprisingly, he sought medical attention. Continue reading →

A Long Vanished Waterworld

By: | January 3, 2011

A few years ago, a colleague and I hired a cab to journey across the Sahara Desert, from a tiny oasis town to Luxor in the Nile Valley. Before we could head out, however, the driver insisted that we anoint ourselves with perfume he brought for the occasion–a ritual cleansing to protect us from evil spirits and the perils of our journey, the most likely of which was engine trouble. When we finally pulled into Luxor 12 hours later, the three of us were parched and coated head to toe in dust.  As I rehydrated in a hotel bathtub, I felt like Lazarus rising from the dead.

Even today, in the age of the internal combustion engine, a Sahara crossing is not to be taken lightly. So it’s no wonder that archaeologists have long dismissed the possibility that our ancient ancestors–early modern humans–ventured successfully across the Sahara more than 100,000 years ago, as they journeyed out of their southern homeland. The Nile Valley seemed a much easier route.

But new research strongly suggests that the Sahara would have been a land of earthly delights for early Homo sapiens. Continue reading →

UPDATE: New Person of LWON Indisposed

By: | January 3, 2011

We’re sorry, but Thomas Hayden, the New Person of LWON, will be unable to post today as promised.  Instead we present for your delight and edification, Heather.  Tom will be back as soon as possible and in the meantime, we send him our best wishes for recovery.

Credit: Jehan Georges Vibert

New Person of LWON

By: | December 31, 2010

Please meet Thomas Hayden, a new Person of LWON.  And let’s get this out of the way early:  he is not and never has been married to any movie star whatever.   He writes about ecology, energy, environment, and evolution and though he’s entirely a peaceable, friendly fellow, he writes a lot about war.  And sex.   You’re going to like him.  His first post is Monday morning.

Photo credit: Mikhail Evstafiev

The Secrets in a Neanderthal’s Smile

By: | December 30, 2010

Every time I see a new scientific paper bearing the name of Dolores Piperno, I sit up and pay very close attention. Piperno is a force to contend with in the world of archaeology, a researcher whose work is so unconventional and yet so rigorous that she has won over a small legion of skeptics and naysayers and helped to found an entirely new field of research.

The battle of Piperno v. the old guard hinged on something seemingly arcane, but critical to the field of archaeology–the identification of plant microfossils. The old guard only accepted evidence from one kind of microfossil: pollen. But Piperno, now the Curator of New World History at the Smithsonian’s National Museum of Natural History, learned to detect and differentiate between an impressive array of other ancient microfossils. Continue reading →

Question of the Year: What is Life, Anyway?

By: | December 29, 2010

As we near the end of 2010, everybody’s talking about the biggest science stories of the year. I’ve been thinking about these four:

May 20: Craig Venter’s team synthesizes a bacterial genome in the lab, sticks it into an empty bacterial cell, and watches it replicate. Venter calls it the “first synthetic cell“; many headlines prefer “synthetic life“. Controversy ensues.

July 23: NASA scientists take the new Mars rover, Curiosity, for a test drive. When it heads to the Red Planet, in late 2011, Curiosity will hold several instruments equipped to examine whether Mars has “environmental conditions favorable for preserving evidence of life, if it existed.” Continue reading →

Abstruse Goose: Convergent Subsequence

By: | December 28, 2010

The title is a little joke about a math term, “convergent sequence.”  No way on earth can I understand convergent sequences and I doubt if anybody can explain it to me.   “Converging consequences” — now that makes a kind of horrible sense, like maybe an east coast snow storm.  Anyway.  I hope this will be a nice thought for the new year.

You can click it bigger, if you want to read the fine print.

Credit:  http://abstrusegoose.com/1