Archive for the ‘Science’ Category

Monkeys in Texas

November 1, 2008

Well, not monkeys per se.  A dramatic fossil find by paleontologists from Duke Univesity reveals that primates persisted in Texas longer than anyone thought, untl at least 43 million years ago.

That long ago, of course, Texas was covered by tropical forest and active volcanoes.  Nowadays, the climate has cooled and the tropical biome is gone, so most would say that the native primates are extinct there, but I would disagree.   Just look at the Texas School Board.


Gratuitous Boobies

August 1, 2008


You could keep a nice garden there

June 27, 2008

We’ve been exploring Mars for only a few decades or so, and NASA is already planning to move in! They’ve even got their first cash crop picked out: asparagus.

I’m being a tad dramatic. What really happened: Phoenix, NASA’s newest Martian lander, completed a preliminary analysis of the soil surrounding its landing site, and found it very similar to soil on Earth. The soil is alkaline, just like life-friendly soil on the blue planet, and it contains such minerals as magnesium, potassium, and sodium. Nothing toxic has been detected so far. Steve Kounaves, the lead chemist of the Phoenix project, said, “You might be able to grow asparagus in it really well.”

NASA scientists are reportedly “flabbergasted” by this discovery. Soil conditions appear to be far more conducive to life than they had dared to dream. Couple this with the probable presence of large amounts of water ice just beneath the surface at Phoenix’s landing site, and the chances that life may once have existed on Mars improve dramatically.

Your ancestor was a wet bag

June 26, 2008

So was mine, so don’t feel too insulted.

Dr. PZ Myers of Pharyngula has written a wonderful piece on new evidence that the most recent common ancestor of all chordates (i.e. you, me, dogs, goldfish, lancelets, and sea squirts) was a sessile, seafloor-dwelling suspension feeder. This creature’s larva were probably lancelet-like fishoids, with a springy notochord (a precursor to the vertebrate spinal cord) and a simple tentacle-ringed mouth. At some point, in one of the ancestors of the vertebrates, one of the larva accrued a mutation that prevented it from reaching adulthood, and it maintained its fishlike body plan, eventually giving rise to true fishes, and later every other vertebrate.

I will attempt no further summary of the article. Read it. Read it now!

Once you’ve read Dr. Myers’ piece, please note this excellent song lyric posted by a commenter named Becca:

It’s a long way from amphioxus, it’s a long way, to us.
It’s a long, long way from amphioxus, to the meanest human cuss
cause it’s goodbye to fins and gillslits, and welcome lungs and hair
it’s a long long way from amphioxus, but we all came from there

(To be sung to the tune of “It’s a Long Way to Tipperary,” in case you hadn’t figured it out.)

Most primitive tetrapod found

June 26, 2008

Today’s edition of Nature carries an article describing the most primitive tetrapod (four-legged creature) ever discovered. The creature, thought to have lived 365 million years ago, is ten years younger than the infamous Tiktaalik, but while Tiktaalik is thought to have more characteristics of fish than of tetrapods, the new discovery is thought to be a true tetrapod.

Some interesting notes:

The creature, named Ventastega curonica, is not the oldest tetrapod ever discovered, but it is the most primitive. This means that its features are more similar to fish (the ancestors of all land animals) than any other known tetrapod. This seems out of sequence with the usual trend in the fossil record, where more primitive animals are found in older rocks, and more complex creatures are found in newer ones. Because of this, the study’s lead author, Per Ahlberg, does not think that Ventastega is an ancestor of modern tetrapods, but rather an evolutionary branch that died out sometime in the past. That would have made it something of an evolutionary holdover in its time, somewhat like horseshoe crabs and egg-laying mammals today.

At the site in Latvia, no legs were found, but researchers were able to deduce that Ventastega had four legs through the shape of the pelvis and of other joints. Parts of the skull, shoulders and pelvis were all that was turned up.

Ventastega was probably three to four feet in length, and probably ate fish. It probably lived in shallow water, where its legs allowed it to move more efficiently than fins would have done. (Scientists say “probably” a lot.)

I love stories like this! Let’s hope paleontologists keep unearthing these key bits of the story of life.

E. coli evolutionary breakthrough

June 19, 2008

This is old news, so you can feel free to move on if you already know about it. (Unless you want to see me tear into Answers in Genesis at the end!)

Dr. Richard Lenski of Michigan State University (my mother’s alma mater! Represent!) has been observing 12 populations of E. coli bacteria for twenty years. Recently, one of these populations did something remarkable: it evolved the ability to metabolize a nutrient that is normally unusable by E. coli.

This is only the beginning of the excitement, however. When Lenski revived samples of that particular population that he had frozen periodically over the course of the experiment, he found that only the samples frozen after about 20,000 generations, or halfway through the experiment’s duration, evolved the new trait again. Some presumably unlikely mutation occurred which “primed” that population to evolve the trait. The other 11 populations have not evolved the trait, and presumably will not unless a similar mutation occurs within their numbers.

The experiment establishes the role of historical contingency in evolution. Organisms are never perfectly adapted to their environment, because the adaptations available to them are constrained by the changes that have happened in the past. Just like humans can’t evolve wings at the shoulders, because no structures exist there to give rise to wings, E. coli can’t evolve the ability to metabolize previously unusable nutrients unless some more fundamental change takes place first.

Of course, these results fly in the face of creationists who claim that such unlikely events simply can’t happen. Right on cue, Answers in Genesis released a statement on the research. I won’t do a point-by-point breakdown of the argument, because there really is only one point: this is an example of micro-evolution, not macro-evolution. The new bacteria are still bacteria, they’re not cows or dogs or peach trees. This cannot be taken as evidence for “molecules-to-man.”

My rebuttal? Until they demonstrate how small changes cannot add up to large changes over time, their argument is worthless. While they’re at it, they should also explain why one cannot walk to New York from LA, given enough steps, or how someone cannot deposit a thousand dollars in the bank, given enough pennies.

Enough of that. This is very exciting research. Next, scientists should try to produce a strain of E. coli that can metabolize dust and clutter; then I won’t have to clean ever again.

Through the Looking Glast

June 11, 2008

You have no idea how long it took me to come up with that pun. I’ve wasted my life.

I’m writing, of course, about the Gamma-ray Large Area Space Telescope, or Glast. It was launched today on top of a Delta II rocket, and once it reaches orbit it will be inspected for about two weeks before being set on its mission: to scour the skies for cosmic sources of radiation. I picked up the story from BBC News.

Gamma rays are the most energetic members of the electromagnetic spectrum, and they are emitted only by the most powerful, the most massive, the most destructive objects in the universe. These include the supermassive black holes at the centers of galaxies, the neutron stars that rotate dozens of times in a single second, and catastrophic explosions. When the telescope is activated, it may even turn up previously unknown sources of gamma rays.

One mystery on which Glast may shed light is the immense jets of matter blasted into space by supermassive black holes. These jets stretch out into space to immense distances, and extend above and below the galactic plain. Experts currently don’t have an explanation for what powers these jets; Glast may provide a clue or two.

This is what the space program should be about: probing into the fundamental nature of the universe. I can’t wait to see what images it returns.

Learning begins in the egg

June 5, 2008

Another fascinating article from BBC News. Scientists at a French university discovered that cuttlefish embryos apparently keep an eye on potential prey… from inside their own eggs.

That’s not to say that the embryos will track a particular animal throughout development, and then spear tackle it once they’re free from the egg. Dr. Dickel and his colleauges at the University of Caen Basse-Normandy placed crabs near some cuttlefish eggs, and none at all near others. The cuttlefish that hatched from the eggs exposed to crabs showed a strong preference for crabs upon emerging, while those not exposed to any particular prey type showed a preference for shrimp. This indicates that cuttlefish embryos are capable of visual learning from within the egg. I don’t know about you, but that blows my mind. I love this stuff!

The article goes on to point out that other animals are known to learn during embryonic development. Seagulls are able to learn their parents’ alarm calls before hatching, and frog embryos can learn the chemical signatures of the water surrounding them before emerging as tadpoles. Cuttlefish embryos, however, are the only ones known so far to learn visually while still in the egg.

Has anyone looked into this for mammals? When I have kids, can I save them a few years of public school while they’re still comfy in the womb?

The International Space Station unites with Hope

June 3, 2008

The Japanese module Kibo (from the Japanese word 希望 (kibou), or hope), was attached to the ISS today. Developed by the Japan Aerospace Exploration Agency (JAXA), it is the largest compartment on the station, and will be dedicated primarily to medical experiments. The other two compartments were supplied by the U.S.-based NASA and the European Space Agency.

More information on Kibo can be found here.

Another interesting tidbit from the BBC article above: the International Space Station is scheduled to be completed in 2010, at which time the current space shuttle orbiter fleet will be retired. The replacement? The Orion Crew Exploration Vehicle, which NASA hopes may be ready by 2013. This craft is meant not only to carry astronauts to the ISS, but also to the Moon and beyond. It’s all pretty exciting, but I have my reservations about manned space flight to other planets. Maybe I’ll explore that in another post.

Something must be done about this

June 3, 2008

This news is over a week old, so please accept my apologies for that. I found it too interesting (and disturbing) to pass up.

According to a survey funded by the National Science Foundation, about one in eight of US high school science teachers presents intelligent design in a positive light. One in eight of our publicly funded science teachers tells students that intelligent design is a viable and scientific explanation of the origin of biological diversity.

In other words, one in eight of US high school science teachers is teaching a falsehood to students.

I suppose this should come as no great surprise. The article also notes that between 12 and 16 percent of high school teachers in the US are creationists, one of six of which come in the young-earth flavor. These numbers line up nicely with the proportion that teach ID.

Regardless of the reason, however, high school teachers cannot be permitted to continue presenting religious doctrine to students as if it were legitimate science. Some steps I can produce from the top of my head for combating this:

  1. Any high school science students who catch their teacher presenting intelligent design should point out the Dover ruling, which effectively banned intelligent design in public classrooms. If that doesn’t work, they should go to the principal, and if that doesn’t shut down the ID lessons, they should go to the National Center for Science Education, or even the ACLU.
  2. Science teaching methods courses in universities should emphasize the central importance of evolutionary theory in biology. I’m sure most already do this (though mine didn’t.)
  3. More science outreach could be instrumental in decreasing the proportion of the public who doubt evolution. For instance, if networks like The Discovery Channel were to show a series of documentaries on evolution, this would put a significant damper on the idea that “evolution is just a theory,” or the idea that there is a controversy among scientists about whether evolution accounts for biological diversity. (They could put it in between the shows about retrofitting motorcycles.) This is not something that can be mandated, of course.

Those are just a few ideas from a humble science teacher. In any case, it all comes down to this: it is the teachers who determine what is presented in their classrooms, not the courts. That’s where the change needs to happen.