Tag Archives: biology

New research on aging hints we might be able to prevent it

800px-Adult_Caenorhabditis_elegans It appears the prevailing theory as to why we age could be wrong–and that would be good news for anti-aging research (Via PhysOrg):

Age may not be rust after all. Specific genetic instructions drive aging in worms, report researchers at the Stanford University School of Medicine. Their discovery contradicts the prevailing theory that aging is a buildup of tissue damage akin to rust, and implies science might eventually halt or even reverse the ravages of age.

The “rust” the prevailing theory uses to explain aging is essentially the accumulated wear and tear caused by “toxins, free-radical molecules, DNA-damaging radiation, disease and stress.” But the results of the Stanford research, led by Stuart Kim, professor of developmental biology and of genetics, don’t fit that theory. Instead, they found that that hundreds of age-related genes in C. elegans nematode worms were switched on and off by a single transcription factor–a kind of signalling molecule–called elt-3, which becomes more abundant with age. Two other transcription factors that regulate elt-3 also changed with age. As a result, normal development becomes unbalanced in older organisms, something the researchers call “developmental drift.” And now that this mechanism has been found in one organism, scientists can look for it in others–including humans.

The idea that this developmental drift is behind aging rather than “rust” would explain why there are many animals that live far longer than humans:

Some tortoises lay eggs at the age of 100…There are whales that live to be 200, and clams that make it past 400. Those species use the same building blocks for their DNA, proteins and fats as humans, mice and nematode worms. The chemistry of the wear-and-tear process, including damage from oxygen free-radicals, should be the same in all cells, which makes it hard to explain why species have dramatically different life spans.

***

If aging is not a cost of unavoidable chemistry but is instead driven by changes in regulatory genes, the aging process may not be inevitable. It is at least theoretically possible to slow down or stop developmental drift.

The research has been published in the July 24 issue of Cell; you can download the original paper in PDF format.

Having just celebrated another birthday and thus entered my 50th year on this planet, I can only say, “Faster, please!”

(Image: Wikimedia Commons.)

[tags]aging, biology, genetics, immortality[/tags]

Martian chronicle: Working the interplanetary night shift

MarsThink your schedule is crazy? Spare a thought for the 150 Phoenix Mars lander scientists:

“Living on a Martian day is like traveling two time zones every three days over and over,” said [Laura] Barger, who is an instructor of medicine in Harvard’s Division of Sleep Medicine. “Everyone has a circadian clock. . . . When it isn’t able to synchronize with a Martian day, you get sleep disorders, decreased alertness and decremented performance.”

NASA is experimenting with soft-light boxes and an adjusted sleep schedule to help the Mars explorers stay alert. And it’s funding the two-year, $350,000 Harvard study in the hopes that results might help doctors, police, firefighers, and other earthlings who work skewed shifts.

[Mars image: jasonb42882]

Becoming Batman: Kinesiology weighs in

Brazilian BatmanIt’s, well, possible, but not sustainable, says University of Victoria, British Columbia movement researcher, neuroscientist, and martial arts practitioner E. Paul Zehr, author of the forthcoming Becoming Batman: The Possibility of a Superhero (Johns Hopkins University Press [!]). The most plausible thing about Bruce Wayne, the comics-savvy Zehr told Scientific American:

You could train somebody to be a tremendous athlete and to have a significant martial arts background, and also to use some of the gear that he has, which requires a lot of physical prowess. Most of what you see there is feasible to the extent that somebody could be trained to that extreme. We’re seeing that kind of thing in less than a month in the Olympics.

Least plausible:

Most of the time, in the comics and in the movies, even when he wins, he usually winds up taking a pretty good beating. There’s a real failure to show the cumulative effect of that.

If you’re thinking of superheroing, stay off the steroids.

There is one comic where he did go on steroids. He went a little crazy and he went off them again.

[Image: S

Evolution observed in laboratory bacteria

Image of E Coli in the labFor the first time, a major evolutionary change has been observed in laboratory conditions, giving even greater weighting to evolutionary theory. The bacteria used, a strain of E. Coli, was first introduced into the Michigan State University lab twenty years ago by evolutionary biologist Richard Lenski. Some 44,000 generations later, the bacteria are still reproducing.

Somewhere around the 31,500th generation, the E. Coli developed a trait not present in the original strain: they began to be able to metabolise citrate, the inability of which is one of the main ways scientists distinguish E. Coli from other bacteria. Importantly, the paper says that evolution occurs as a sum of the previous steps of mutation and that as this history varies between groups of creatures, evolution is a random and unpredictable act.

“It’s the most profound change we have seen during the experiment. This was clearly something quite different for them, and it’s outside what was normally considered the bounds of E. coli as a species, which makes it especially interesting,” says Lenski.

One of the main criticisms of evolutionary theory has been that it is a theory that hasn’t been observed in the real world. Creationists are going to have a hard time explaining this result away, one suspects.

[via Daily Kos, image by scaliber001]

Farewell, third molars – five vestigial organs that humans no longer need

Four Wisdom TeethNew Scientist has a top-five run-down of vestigial organs that humans (arguably) no longer need.

(I imagine a number of readers will share in my vehement agreement that wisdom teeth (more properly known as third molars) are on the list … my unreasoning dislike of dentistry has been mentioned here before, and the consequences of an overcrowded jaw were a major contributing factor to that reaction.) [image by Lone Primate]

So, now we know which stuff we don’t need, how do we go about removing it from the human system? Permanently?