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The FDA has approved a vaccine that protects against some types of human papillomavirus that can lead to cervical cancer. I've discussed the vaccine before (here and here.)
Adventures in Ethics and Science has some discussion on the political and economic front.
This week's Nature has a news article about the large and diverse role that viruses play in the ecology on this earth, and the insights about the past that we are gaining from them. If you can name an organism, there is probably a virus that infects it.
Continue ReadingHints of the vast, unexplored viral world first emerged during the 1980s. Researchers at the University of Bergen in Norway, with the help of a new electron-microscopy technique, showed that viral concentrations in some aquatic habitats were up to 10 million times greater than previous estimates. Viral particles per millilitre ranged from 60,000, deep beneath the Barents Sea, to 254 million, from the surface waters of Germany's Lake Plussee.
These viruses are a large reservoir of genetic diversity that can wind up in the host genome. (FYI, a phage is a virus that infects bacteria.)
Since then researchers have discovered huge numbers of viruses wherever they have looked, from 2,000 metres below the surface of Earth to the sands of the Sahara Desert, from acidic hot springs to polar lakes. In total there are now thought to be some 10^31 viral particles on the planet — an astronomical figure that one researcher recently described as 250 million light years' worth of viral genes laid end to end.
Then, in the mid-1990s, researchers started to grasp the dazzling variety that exists within this viral multitude. Biologists discovered that the known and cultured viruses represented just a fraction of their respective groups. From one cubic metre of seawater to the next, there was more genetic diversity in viruses than found in any other known group of organisms.A big question now is the degree to which this super-organism extends its tentacles into host genomes. It has long been known that bacteria use genes acquired from prophages — phages that insert their DNA temporarily or even permanently into the DNA of their host — to gain competitive advantage and exploit new environments. Indeed, work reaching back decades has shown that prophage genes carried by bacteria are responsible for producing the primary toxins associated with diseases such as diphtheria, scarlet fever, food poisoning, botulism and cholera.
I think this next bit is fascinating to think about.Phage DNA has also made it into the human genome, despite the fact that phages target bacteria. The source was our mitochondria, the energy-producing capsules found in our cells and thought to be the descendants of a formerly free-living bacterium. During evolution, phage genes from the mitochondrial genome have transferred into our main genome, housed in the cell's nucleus. There, they help copy and express the few bacterial genes still present in the mitochondrial genome. Recently, this same phage DNA has been spotted in various modern bacteria belonging to the group from which mitochondria are thought to have descended. That supports the idea that the gene made its way from virus to bacterium to cell nucleus, where it now plays a key role in the molecular circuitry that drives all multicelled organisms.
The article also mentions retroviral remains in our genome, some of which appear to play a function in our physiology.
Virology isn't just about disease anymore.
Nature 441, 683-685 (8 June 2006)
I've been reading Elder Bruce C. Hafen's book Covenant Hearts: Marriage and the Joy of Human Love. Here is a passage about Adam and Eve that I liked.
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--Begin Quote--Adam and Eve's story sets the pattern for our own lives. Their experience is the primal story about how the great "plan of hapiness" (Alma 42:16) actually works--and the story is about a married couple. The story has six archetypal elements.
--End Quote--
It seems to me that the story of Adam and Eve is much more about these archetypal elements than about details of creation.
PLoS Medicine has an essay describing one connection between biodiversity and human health.
In this Essay, we describe how disease risk is influenced by biological diversity and, specifically, how some host species act to reduce the risk of transmission of virulent zoonotic pathogens to people. This represents an exciting area of study where ecologists, conservation planners, and physicians can work together to reduce disease risk and maintain biological diversity. In a world where climate change may allow vector-transmitted diseases to spread from the tropics into the temperate zone, it may be sensible to conserve biological diversity for the purely selfish reasons of protecting human health.Continue reading...
You decide.
KIEV (Reuters) - A man shouting that God would keep him safe was mauled to death by a lioness in Kiev zoo after he crept into the animal's enclosure, a zoo official said on Monday.As for me and my house, we will stick with good old-fashioned snake handling. Continue reading...
"The man shouted 'God will save me, if he exists', lowered himself by a rope into the enclosure, took his shoes off and went up to the lions," the official said.
"A lioness went straight for him, knocked him down and severed his carotid artery."
In the Editor's Introduction of the most recent FARMS Review (17/2, 2005), Daniel Peterson included a response by Ryan Parr to Simon Southerton's reponse to Parr's review of Southerton's book in the last issue of FARMS review.
Parr's response is longer than I want to quote here, but Peterson follows up with a more succinct response that effectively summarizes Parr.
With Dr. Parr, I too am struck by Simon Southerton's effective concession of the fundamental point made by writers for FARMS on the subject of Amerindian DNA and the Book of Mormon over the past few years, and I think it bears repeating: "In 600 BC there were probably several million American Indians living in the Americas. If a small group of Israelites, say less than thirty, entered such a massive native population, it would be very hard to detect their genes today." Thus, the so-called issue of Amerindian DNA and the Book of Mormon proves not to really be about genetics at all. It actually comes down to how the Book of Mormon is to be interpreted and to how its history is pictured. Are we to be ruled by the Mormon "urban legends" to which, even after he himself has repudiated his faith, Simon Southerton insists we are bound, or should we favor what the text of the Book of Mormon itself says (and does not say)? The answer seems rather obvious.
President Hinckley's talk last General Conference got me thinking about the turnover of Apostles in the Twentieth Century. Specifically, I thought about Joseph Fielding Smith--he was certainly around for a long time, so I decided to graph up some relationships.
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The figure below shows the tenure of all of the members of the Quorum of the Twelve from Reed Smoot to Marvin J. Ashton, in order of seniority. All Apostles listed below Joseph Fielding Smith (red bar) were called after him, and while he was alive. Presidents of the Church are indicated in green (except JFS). The shaded portion represents the timespan of Joseph Fielding Smith's call as an Apostle until his death. There were a couple of unique situations where someone was an Apostle or in the First Presidency, but not in the Quorum of the Twelve. If I remember right, I only included beginning dates relevant to membership in the Quorum of the Twelve. In most cases the end dates represent death; an exception is Richard Lyman, who was excommunicated and not restored to the Apostleship after re-baptism. I was primarily interested in seniority and succession in the Quorum of the Twelve, so service in the First Presidency is not indicated (eg. J. Reuben Clark).
Here are some of my observations:
- Almost a whole Quorum of the Twelve came and went between Joseph Fielding Smith and Harold B. Lee. (A similar gap existed between Ezra Taft Benson and Howard W. Hunter.)
- Joseph Fielding Smith was senior to 30 men in the Quorum of the Twelve (although some of those men served in the First Presidency.) Of those, only 14 were alive when he died.
- I had not realized how long David O. McKay served; he and Joseph Fielding Smith served together for a long time. Who knows how the Church would have been different if the two were switched in seniority.
- The person called as an Apostle to fill the vacancy in the Quorum of the Twelve created by the death of Joseph Fielding Smith was none other than Bruce R. McConkie (his son-in-law).
- Joseph Fielding Smith was ordained an Apostle two-and-a-half months before the birth of Gordon B. Hinckley. (April 7 and June 23, 1910, respectively.)
I've mentioned before that I get daily articles put out by Answers in Genesis. They've been serializing some books, and the latest is Creation: Facts of Life by Gary Parker. It has been around since at least 1980, but the most recent version is from 1994.
As I read the first chapter my baloney meter was going off. The chapter attacks the whole concept of homology with the old argument of: 'features are similar because of common design, not common descent.' As I read some of the specific examples I began to be very suspicious. First of all, I'm always suspicious when a creationist quotes mainstream scientists in support of a creationist argument. I'm even more suspicious when a creationist asserts a fact that is so obviously counter to evolution that it would seem that scientists must be either fools or agents of evil to go on in the face of it.
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I won't get into all of the chapter--I've wasted enough time on it already. I will limit my discussion to this claim:Lysozyme is the enzyme in tears that “bites holes” in the cell walls of bacteria so that they explode. (Listen for the “pop” on a quiet evening!) Egg whites are rich in the same enzyme, and that’s what keeps eyes and egg whites from getting easily infected.
Objective evidence shows that human lysozyme is more closely related to that of chicken than any other mammal? Well, let's look into that one.
By comparing lysozyme and lactalbumin, Dickerson was hoping to “pin down with great precision” where human beings branched off the mammal line. The results are surprising. In this test, it turned out that humans are more closely related to the chicken than to any living mammal tested! Every evolutionist knows that can’t be true, but how can he get around the objective evidence? In his concluding diagram, Dickerson slips in a wiggly line for rapid evolution, and that brings the whole thing back in accord with his evolutionary assumptions. But notice that his protein data, the facts that he observed, did not help him at all with his evolutionary idea.
First of all, the quote from Dickerson comes from a 1969 book--not really accessible. But from what I can find, Parker is apparently mangling a discussion about rates of evolution. (I'll explain in the comments if anybody really wants me to.)
The lysozyme claim has been around since at least 1980, and keeps popping up even though it has been repeatedly refuted. (See here, here, and here for background.)
A more recent book by a different author (2000) that claims to have up-to-date information apparently also repeats the claim, since it is contained in the free accompanying study guide (pdf).
So for fun, I poked around on a publicly accessible database to see what I could find. Below, I show the first third (approximately) of the amino acid sequence of lysozyme from human, chimpanzee, mouse, and chicken. I don't have software at home to do it for me, so I went through the sequences and highlighted any differences from the human sequence by hand. 
Lo and behold, human and chimpanzee are the same, mouse is somewhat different, and chicken is the most different. Now this is only a portion of the sequence, but it is pretty obvious that the claim that chicken is closer to human than any mammal is false.
So there you have it. I've spent more time than I should have on this claim. I hope you've enjoyed it.
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