Archive for the 'evolution' Category

The argument for running barefoot

July 16, 2009

From Wired Science:

“People have been running barefoot for millions of years and it has only been since 1972 that people have been wearing shoes with thick, synthetic heels,” said Daniel Lieberman, a professor of human evolutionary biology at Harvard University.

Strong evidence shows that thickly cushioned running shoes have done nothing to prevent injury in the 30-odd years since Nike founder Bill Bowerman invented them, researchers say. Some smaller, earlier studies suggest that running in shoes may increase the risk of ankle sprains, plantar fasciitis and other injuries. Runners who wear cheap running shoes have fewer injuries than those wearing expensive trainers. Meanwhile, injuries plague 20 to 80 percent of regular runners every year.

The author tried it. He (?) advises starting slow, no more than 10 percent barefoot running in a week. Here’s a barefoot strengthening program (.doc).

A related JR classic: The evolutionary origins of the New York City Marathon

[H/T: Gene Expression]


A disgusting way to control hay fever

July 16, 2009

From New Scientist:

In the mid-1970s, while working at the UK’s Medical Research Council Laboratories in Surrey, he [John Turton] intentionally infected himself with hookworms in an attempt to relieve his chronic hay fever. It worked. For two summers while he harboured the parasites, his allergy abated, only to return when he was free of them (The Lancet, vol 308, p 686).

Here’s what that means:

Hookworm larvae […] enter through the skin and make their way through the bloodstream to the lungs, where they pass through the thin-walled blood vessels. They then travel up from the lungs into the trachea, only to be coughed up and swallowed, allowing them to reach the small intestine where they develop into adult worms. “The potential protective effects of hookworm infections on asthma may be related to these parasites’ lung migration phase,” Flohr says.

Worms suppress the immune system, which could have adverse effects in the long run.

Not all worm infections are the same. Read the whole story to find out which disgusting parasite is right for you.

[H/T: Seth Roberts]

Blinking twice at Carl Zimmer

July 1, 2009

I have to thank Carl Zimmer, science writer extraordinaire, for restoring a bit of my sense of wonder in science, and in our mutual profession. His much-emailed NYTimes two-pager about firefly mating practices is, as Charlie Petit might have said, a simple story, elegantly told.

My sentimental turn happened right about here:

In recent years scientists have analyzed the DNA of fireflies to figure out how their light has evolved. The common ancestor of today’s fireflies probably produced light only when they were larvae. All firefly larvae still glow today, as a warning to would-be predators. The larvae produce bitter chemicals that make them an unpleasant meal.

I guess it was remembering how beautiful evolution is. It was also really cute when he described how the researcher clicked her penlight twice and and got a firefly to flash back. Picking up:

As adults, the earliest fireflies probably communicated with chemical signals, the way some firefly species do today. Only much later did some firefly species gain through evolution the ability to make light as adults. Instead of a warning, the light became a mating call. (An enzyme in the firefly’s tail drives a chemical reaction that makes light.)

The more Dr. Lewis watched firefly courtship, the clearer it became that the females were carefully choosing mates. They start dialogues with up to 10 males in a single evening and cankeep several conversations going at once. But a female mates with only one male, typically the one she has responded to the most.

It may have something to do with advertising a male’s “nuptial gift” of protein, injected along with the sperm, which sustains the female during reproduction.

For more firefly science, read Steven Strogatz.

Adaptationism gets no rest in latest sleep research

June 16, 2009

From an interesting Time article:

According to new research presented last week at the annual meeting of the Associated Professional Sleep Societies in Seattle, adequate sleep may underpin our ability to understand complex emotions properly in waking life. “Sleep essentially is resetting the magnetic north of your emotional compass,” says Matthew Walker, director of the Sleep and Neuroimaging Lab at the University of California, Berkeley.

The adaptationism:

“If you’re walking through the jungle and you’re tired, it might benefit you more to be hypersensitive to negative things,” he says. The idea is that with little mental energy to spare, you’re emotionally more attuned to things that are likely to be the most threatening in the immediate moment. Inversely, when you’re well rested, you may be more sensitive to positive emotions, which could benefit long-term survival, he suggests [such as “finding a wife”].

The cognitive psychology:

Walker suggests that one function of REM sleep – dreaming, in particular – is to allow the brain to sift through that day’s events, process any negative emotion attached to them, then strip it away from the memories. He likens the process to applying a “nocturnal soothing balm.” REM sleep, he says, “tries to ameliorate the sharp emotional chips and dents that life gives you along the way.”

The threat:

“If you don’t let go of the emotion, what results is a constant state of anxiety,” he says.

I let myself sleep in this morning. I’m feeling pretty good about that.

Sea lamprey to U.S. cybersecurity: Yes we can!

May 31, 2009

Remember how U.S. cybersecurity sucks?

Here’s Ars Technica‘s John Timmer on the new cybersecurity report [pdf]:

Perhaps the most striking thing about the report, however, is that it suggests that the US may be facing the prospect of being left as a technological backwater when it comes to security, and a national effort will be required to avoid that fate. The authors suggest a historic analog: “similar to the period after the launch of the Sputnik satellite in October, 1957, the United States is in a global race that depends on mathematics and science skills.” In response, it suggests that the new office develop a research and development framework, and accompany it with a public information campaign that will stress the importance of security considerations. If necessary, the government should incentivize the use of secure practices and equipment by private industry through programs like targeted tax breaks.

From Digits, the WSJ tech blog, here’s one expert’s reaction:

“They’re suggesting in this paper that if you don’t have good security, that you’ll be punished for it. The problem is that this is an evolving threat,” he said. “They seem to be waving the stick around a lot without having any serious carrots.”

I have absolutely no expertise in this area, so I’ll just point to some cool ideas for modeling computer security on the immune system.

While I’m at it, did you know sea lampreys have an unexpectedly sophisticated immune system?


From Science magazine’s Origins blog:

These eel-like creatures are often called “living fossils” because they are thought to have changed little since they arose 450 million to 500 million years ago, as part of a branch of jawless creatures that split off early from the rest of the vertebrate tree. Lampreys and hagfish are the only survivors of that jawless branch, and accumulating evidence indicates that the animals have developed an immune system far different from that of other vertebrates, including people. Today, in Nature, a team led by Max Cooper of Emory University in Atlanta, Georgia, unveils the latest chapter in this emerging evolutionary tale, providing data indicating that the sea lamprey has its own versions of B and T cells, the two cell types central to the so-called adaptive immune response found in people.

It’s not clear yet if the lamprey evolved its immune powers independently of the rest of us vertebrates, but if so, Holy convergent evolution, Lamprey-man!

I guess the lesson for us is this: if a living fossil can evolve itself an adaptive immune system, then surely the U.S. can find a way to keep the free world safe from even the wiliest of Chinese and Russian Lawnmower Men.

Update: NYTimesContractors Vie for Plum Work, Hacking for U.S.