Archive: February, 2012
Scientists have long wondered why our brains contain proteins called prions, which from a medical standpoint seem like a huge liability. The prions in our brains make us vulnerable to mad cow disease and other brain wasting conditions that are caused by misfolded versions of these prions that clump up. It was a shock to the scientific community that any infection could be transmitted not by an organism but by a protein - an inanimate molecule. That discovery eventually led to a Nobel Prize for biologist Stanley Prusiner.
Now, research published yesterday in the journal Nature shows that yeast cells carry prions that can enhance survival, helping the organisms adapt to stressful conditions. Prions not only spread disease, they can also pass traits from one generation to the next. In doing so, they may allow an alternative mechanim for evolution to proceed.
Science News has a nice summary of the research, which used 700 strains of yeast to show that prions can pass on traits, possibly allowing the cells to "try out" changes without committing them to the genetic code.
People who claim to want "proof" of evolution would benefit from reading Darwin's On the Origin of Species. It gives a very good picture of how science works and what kinds of evidence scientists consider compelling. What Darwin did there was show why his theory blew creationism out of the water.
I should have written this post in honor of Darwin's birthday last Sunday, but I'm traveling this week, and I'm under the weather. But better late than never. Darwin was born in 1809, the same year Edgar Allen Poe was born. Of the many Facebook and blog posts acknowledging Darwin's birthday, one of the most interesting was on the site Why Evolution is True. There, biologist Jerry Coyne discussed Darwin's writing and why he used to assign On the Origin of Species to his students. I've read about half of it, though I do plan to finish. I felt obligated to read a number of other books in the last few months, including book by authors who were interviewed for this column.
But Origin is a great book and is written for real people. What I've read so far has given me a new appreciation for Darwin's achievements as a scientist as well as the magnitude of the seismic shift he unleashed on the world. Other people, including Darwin's own grandfather, had proposed that plants and animals could evolve, and even that one species could evolve into another. But Charles Darwin was the first to grasp how. He was the one to recognize natural selection as the mechanim by which living things became exquisitely adapted to their environments.
Here's my weekly evolution column, which appears Monday Feb 13 in the Philadelphia Inquirer:
On Star Trek, the aliens often look so human that crew members fall in love with them. But in real life, scientists in the field known as astrobiology can’t be sure alien life would even be carbon-based like us, or use DNA to carry a genetic code.
Some insight now is coming from earthly labs, where scientists are building alternative kinds of genetic codes, and showing how they can evolve.
I’ve often heard scientists rather glibly point to nearsighted people as an example of human degradation. Now that we no longer have to hunt for our food, the thinking goes, natural selection is letting all kinds of defective examples of humanity survive and reproduce. Myopics are always singled out first.
I ‘m biased, since I can’t see the big E on the eye chart, but I can’t help wondering if there’s more to the story. One interesting thing about nearsightedness is that most of us aren’t born that way. I saw quite well before I learned to read, but it was all downhill after that.
Today a kind reader sent me a discussion he was having with some science-oriented, nearsighted friends about a possible connection between myopia and high IQ. A paper written by a Polish team found such a correlation. I had never heard of this before, but it seems plausible that reading hundreds of books could have a positive effect on IQ and a deleterious effect on vision. Apparently, however, the authors of this paper tried to correct for number of books read. Here’s what they found:
Are children with myopia more intelligent? A literature review.
A story from today’s Inquirer describes a badly injured pit bull named Radar, who had been used in dog fighting. He had sustained multiple injuries and was left for dead. While this dog is making a remarkable recovery, I’ve heard from SPCA volunteers that there’s an explosion of dog fighting in the Philadelphia area and a growing shelter population of unwanted pit bulls. Read the story here.
One place where I've been challenged by scientists is on the question of whether non-human animals such as Radar can feel pain. Evolutionary biologists tend to agree with me that of course they do, while some neuroscientists have voiced quite strong disagreement. Animal pain was among the many issues I raised with Richard Dawkins when I met with him last weekend. He told me that scientists who deny animal pain were "disgraceful" and added a few colorful British-isms that start with the letter B. It turns out he's thought deeply about this issue, so I'll have more on Dawkins and the status of non-human animals soon,
I've been collecting a file on dogs and dog fighting, thinking there might be a series of columns to be done about these creatures and the many misconceptions that surround them. Is fighting in their blood or in their “training”? And what happens when they’re adopted into loving homes?
Scientists have dreamed for years of breaking through the ice covering Antarctica’s Lake Vostok. Deep in the interior of the frozen continent, this lake is one of the least hospitable and most isolated environments on the planet, having been sealed in ice for 15 to 34 million years.
Yesterday a Russian group announced they’d drilled all the way through the two miles of ice that cover this lake. If they find any kind of life exists there, it raises hopes that life could exist elsewhere in the universe, including the permanently ice-covered oceans of Jupiter’s moon Europa or Saturn’s moon Enceladus.
A few decades ago, scientists thought all of Antarctica’s frozen lakes would be lifeless, but a few brave scientists have since pierced the ice and taken chilly dives into the smaller lakes, finding they were full of algae and other living things. (On my 1995 trip to Antarctica, I watched drysuit- wearing divers perform this feat.)
This interesting comment came to the Inquirer’s Facebook page after my column ran on the evolutionary implications of “wing bowl”:
- This article leaves much to be desired. The use of sex, fertile, and orgy in an article about chicken wings actually stopped me from reading it.
I did not know the word “fertile” could be offensive. I would recommend to this person that she never ever attend an actual “wing bowl”, especially if she thinks it’s about chicken wings. She might also want to refrain from attending the Wagner Free Institute’s program tomorrow night in honor of Valentine’s Day.
This lecture looks promising even for those of us who find most Valentine’s Day events annoying. Every year universities predictably rope scientists into giving talks about love, relationships and other tired topics. But Scott Gilbert’s talk tomorrow promises to be original and fun, at least for those of us not offended by the facts of life. It starts at 5:30 and it’s free though they’d appreciate a $10 donation.
(Note to readers: This was my Inquirer column this week. It ran on the cover of the Health and Science section. Tony Auth was on vacation. He'll be back to illustrate the next column.)
Timing is everything, and if there was ever a scientist whose legacy was tarnished by bad timing, it was Jean Baptiste Lamarck. The French naturalist lived from 1744 to 1829 — and published his own evolutionary theory decades before Darwin’s theory went public in 1859.
In the popular imagination, those who’ve heard of Lamarck tend to associate him with a wrongheaded version of evolution in which giraffes can grant their offspring longer necks by reaching for high leaves. Historians say this unfair portrayal was engineered by Lamarck’s enemies.