Motorized Wheelchair Guided by Thoughts

A company called Ambient is developing a new wheelchair that is controlled by words the user thinks of. The system, called Audeo, uses a neckband to pick up signals in the nerves that control the larynx, or voice box. Obviously, this requires that the operator still has control of those nerves, though he doesn’t have to have control of the other muscles or the coordination that is required for speech. This has the potential to restore some mobility to those who have very little strength or coordination to make purposeful movements. And as this technology is refined, the potential uses are many: users could control other devices, such as a computer or television. If the “vocabulary” of the system is increased, the system could also function as an artificial speech synthesizer that could sense the words the user was trying to say and construct them directly. See New Scientist for more.

Below is a video demonstrating the system.


Potential Sighting of Yangtze River Dolphin

Yangtze River dolphin / baiji
Image credit: Wikipedia.

Earlier this month, I wrote about the likely extinction of the Yangtze river dolphin, also called the baiji. Today’s New Scientist reported that a video shot by a Chinese man on 19 August may show a baiji, though it is difficult to tell from the quality of the footage. Even if it is a baiji, however, one animal is insufficient to repopulate a species. While it is theoretically possible to repopulate from a single breeding pair of animals, in practice, there is typically not enough genetic diversity for this to be successful. It seems likely that even if this sighting is confirmed, the animal is still “functionally” extinct, and that the inevitable “true” extinction has only been delayed by some years.

What has made this especially poignant is that I’ve been reading a book lent to me by a good friend: Last Chance to See, by Douglas Adams (the author the Hitchhiker’s Guide to the Galaxy) and Mark Carwardine. Published in 1990, the documentary is a companion to a BBC radio series highlighting endangered animal species. With his usual wit and humor, Adams narrates their journeys to find these unique creatures. I am just reading the chapter where the group is in China, searching for baijis. Sadly, their effort to draw attention to the plight of the baijis seems to have been futile; less than twenty years later the animal is already extinct or will be so shortly.

At this point, the only potential hope I see is for us to keep the baiji alive long enough (assuming the sighting was real) for us to develop the genetic technology to perpetuate the species. A different part of the book discusses the kakapo, a critically endangered flightless bird found in New Zealand. When Adams asks Don Merton of the New Zealand Department of Conservation about what he thinks the long-term prospects are, he replies:

Well, anything’s possible, and with genetic engineering, who knows. If we can keep them going during our lifespan, it’s over to the next generation with their new range of tools and techniques and science to take it from there. All we can do is perpetuate the during our lifetime and try to hand them on in as good a condition as possible to the next generation and hope like heck that they feel the same way about them as we do. (“Heartbeats in the Night”; p. 142)

It is now up to our generation to develop the science and cultivate the interest to preserve these creatures. And perhaps there is hope: the number of kakapo has apparently doubled since Adams and friends visited New Zealand; there are now eighty-six. And the book, too, lives on in a way; an interested reader maintains a blog following the status of the featured animals and others. (See his entry on the potential sighting of the baiji.)

“Woman Overjoyed by Giant Uterine Parasite”

From the Onion, a parody newspaper, comes this amusing take on a common event:

NEW BRIGHTON, MN—Immediately following a physician’s examination for her menstrual cessation, 37-year-old events planner Janice Crowley told reporters Tuesday that she is “ecstatic” with her diagnosis of a rapidly growing intrauterine parasite.

“I’m so happy!” Crowley said of the golf ball–sized, nutrient-sapping organism embedded deep in the wall of her uterus. “I was beginning to think this would never happen to me.”

(continue reading at the Onion)

While humorous, this article does remind us of just how unusual this physiological state is.

Modern Fish, Coelacanths, Tiktaalik, and Us

Tiktaalik roseae, illustration
An illustration of Tiktaalik roseae from Wikipedia. Credit: ArthurWeasley.

In the last several years, scientists have mapped in detail the lines of descent that resulted in aquatic vertebrates (fish) being able to survive and function outside water—including lines of descent that today have resulted in the mammals. Periodic discoveries stimulate interest in the media, such as the discovery last year of the 375-million-year-old Tiktaalik, or occasional sightings of coelacanths, an order of fish once thought to be long-extinct. But how are these animals related to each other and to us?

New Scientist published an article last week discussing new research into the coelacanth’s fins (specifically, when the difference between the coelacanth’s symmetric appendages and our asymetric appendages arose). But what I found especially interesting was a graphic demonstrating the relationships between extant lifeforms and notable extinct relatives, including when they are thought to have lived.

Diagram showing relationship between extant fish and tetrapods and extinct relatives.
See full-sized image. Source: New Scientist.

Perhaps this will help provide a framework when reading about these fascinating animals.

Aliens as DNA-shaped Dust

In some ways, our biologists are hampered by having only one “scheme” to study. Since all extant life on Earth descended from the same primordial unicellular organism (perhaps 3.5 billion years ago), we all share a remarkably similar biochemistry, even in details. It is difficult to imagine what other systems would be possible, and how fundamentally different they might be. This also means that as we search space for signs of extraterrestrial intelligence, we tend to concentrate on organisms like us. For the most part, we assume that they, too, will be carbon-based, and use water as a solvent for organic chemistry. Silicon and ammonia have been proposed as alternatives, though the available chemistry doesn’t appear as rich. (See Wikipedia’s article on alternative biochemistry for more information.) Then, too, organisms with this alternative biochemistry still would be rather similar to Earth-based life. What other possibilities could there be? Scientists and science-fiction writers have tackled this question for generations.

Scientists in Germany speculate about life in spirals of dust in outer space. Electrically charged dust immersed in plasma (ionized gas) can produce crystals and spirals. According to a New Scientist article, a simulation suggests double-helices could form as well. In addition, two stable states suggests that information could be “encoded” in these structures. If these structures exist, are stable, and can replicate (perhaps by inducing the surround dust to adopt the same pattern), a self-replicating system that could give rise to life would exist—indeed, many would argue that such a self-replicating system were alive. The researchers speculate that the rings of Saturn or Uranus might be regions to find such spirals.

Of course, this is all hypothetical, but I find it fascinating, nonetheless.

Yangtze River dolphin likely extinct

Yangtze River dolphin / baiji
Image credit: Wikipedia.

I was rather upset to see that the Yangtze River dolphin, also known as the baiji (Lipotes vexillifer), is thought to be likely extinct. This freshwater dolphin, which lived only in China’s Yangtze River, is probably the first cetacean (dolphin or whale) to go extinct due to human influence. Of course, humans have been responsible for wiping out species since before recorded history, but it is disturbing that we still do so. Human-induced extinctions are always regrettable events, but I admit I am especially attached to the dolphins, and I find it quite sad to lose a species of such a highly intelligent mammal.

Cetaceans, of course, evolved from land mammals around fifty million years ago. You’d have to go back only another thirty-five million years to find the last common ancestor of humans and cetaceans. That’s less than 2% of the age of the Earth (around 4.6 billion years)!

Regenerating Sea Squirts

A couple weeks ago, in my post “Growing Body Parts,” I briefly discussed the ability of some animals to regenerate damaged body parts. New Scientist reports today on an animal capable of far more dramatic growth.

Israeli scientists studying a species (Botrylloides leachi) of sea squirt found that just a fragment of a blood vessel could regrow a full, adult sea squirt. The article states

Out of 95 fragments they examined, 80 underwent whole body regeneration (WBR). Cells first grouped into hollow spheres, then cell layers in-folded and organs developed until after two weeks an adult sea squirt had grown, capable of sexual reproduction.

Sea squirts are invertebrates that live in the water. They are somewhat close relatives of us, probably the vertebrates’ closest relatives. The most recent ancestor of sea squirts and all the vertebrates (including humans) lived perhaps 565 million years ago. The vertebrates, along with sea squirts and lancelets, make up the phylum Chordata.