More Recent Comments

Friday, March 09, 2007

Have You Heard of Australia?

 
John Wilkins posted a comment on the thread about favorite countries. He said,
Nobody likes Australia, because nobody has ever heard of it. And that's just the way we like it. So don't spoil it, hey?
I take that as a challenge. I think there are lots of reasons for not liking Australia so I'm going to put it to the test. Anyone reading this post will have heard of Australia and I'm even showing you where it is on a world map (see below). Now let's see if people start liking Australia.

Why Children Love Their Security Blankets

 
A recent study examined Why Children Love Their Security Blankets. This is a subject most parents are familiar with and not just because of Linus. The photo on the left shows my daughter when she was much younger. She was trying to retrieve her pink blanket ("Cubby") after it had been washed and hung out to dry. The photo below is of my son showing off "Baba" after five years of continuous use—I think he still misses Baba. (There're probably going to kill me for posting these photos.)

The study asked whether children felt a special attachment to their favorite things ...
New research, published today in the international journal Cognition, suggests that this might be because children think the toy or blanket has a unique property or ‘essence’.

To support this theory, Professor Bruce Hood from the University of Bristol and his colleague Dr Paul Bloom of Yale University, USA, showed that 3-6 year-old children have a preference for their cherished items over apparently identical duplicates.

Children were introduced to a scientific looking machine that could copy any object but was in fact a conjurer’s cabinet where an accomplice inserted replica items from behind a screen.

Professor Hood said: “When offered the choice of originals and copies, children showed no preference for duplicates of their toys unless the object to be copied was the special one that they took to bed every night. A quarter of children refused to have their favourite object copied at all, and most of those who were persuaded to put their toy in the copying machine wanted the original back.”
Duh!

I have a favorite coffee mug, a favorite chair, a favorite shirt, a favorite pair of sunglasses, and a favorite blogger. I don't want no friggin' copies either and I wouldn't put any of those things in the copy machine. (Well, ... maybe I'd try putting PZ Myers in the copier, just to see what happens .... )

Security blankets and other things don't have any special "essence" that needs to be explained. Their unique property is their history. There's only one thing that was given to you by some special person and uniquely belongs to you. You can't copy that. Children aren't stupid. They know the difference between the original and some cheap copy.

This looks like the kind of study that discovered exactly what everyone expects but they have to hype the results in order to make it look exciting. Did anyone really think that my daughter or my son would have traded their very special blankets for a mere copy? How many of you have tried to con your kids when the security blanket got lost, as they invariably do? Didn't work, did it?

Don't anyone try and swap my coffee mug. If you break it, you die.

Happy Birthday PZ Myers

 
I don't remember exactly when I first encountered Paul Z. Myers, as he was known in those days. (Yes, I do know what the "Zed" stands for but I'm not telling.) I think it was in 1994, or possibly 1993. PZ was a brash youngster jumping into the maelstrom of talk.origins with both feet. It wasn't long before he established himself as one of the regular Howlers. I remember that he had a special fondness for Ed Conrad back in those days. Ed had just made an Earth shattering discovery—man was as old as coal—but Prof. Myers wasn't buying it.

I remember getting into a rather heated discussion about something or other in order to set PZ straight. That happened a lot back then. I suspect it was an attempt by me to correct his adaptationist tendencies. You wouldn't know it now but he was actually a fan of the Richard Dawkins version of evolution in the olden days.

Times have changed. And today he's 50 years young! Happy birthday PZ. (The photo was taken on the Sandwalk. That's not an outhouse we're sitting in. It's a small shelter at the end of the path leading directly from the base of the garden to just before it turns left into the woods.)

I looked for his earliest posting to talk.origins in order to present it to him and the blogger world, but I couldn't find it. The best I could do is this one from Oct. 1, 1997. You'll see that even though he was much younger then, he still had what it takes to explain complex ideas to the average reader—although he does seem to go on and on about this "pharyngula" thingy. It's a harbinger of what's coming when he sets up his blog.

... Raff is contradicting Richardson in a way. Raff says "all chordates ...pass through a pharyngula" while Richardson argues that "there is no highly conserved embryonic stage". My main beef with the Richardson article is not the bashing of Haeckel (he is actually quite reasonable in his comments on that matter), but that he is addressing a straw man. He disproves the *Haeckelian* version of a phylotypic stage, that is a stage when all vertebrates are virtually identical, but I don't consider that a viable possibility to begin with. In the quote above, Raff basically outlines the components of the phylotypic vertebrate: somites, pharyngeal arches, notochord, etc. It does not include specialized trophic structures, precise numbers of somites, or a specific size (when Collins published that nonsense claiming all vertebrates passed through a phylotypic stage when they reached the size of 7-8mm, I know of a few jaws that dropped...especially in the zebrafish community, where we work with an animal that doesn't exceed 3mm until it is well into post-hatching larval stages).

For a good example of the difference, look at Fig. 10 (the last one)in Richardson's paper. This is a set of drawings of the heads of various vertebrate embryos, drawn from photographs and far more accurate than Haeckel's stuff. Richardson's point with the figure is to say, "See how different all these animals are!", and yes, there are lots of superficial differences between the embryos.

When I saw that figure, though, my first thought was how much *ALIKE* they all were. All of them were unmistakeable chordates. All had pharyngeal arches, all had somites, all had that same general shape.

I've never seen Dr. Moran use subtlety in any way -- unless, perhaps, you consider public disembowelment a form of understatement?
Paul Z. Myers
July 10, 1997
Richardson was also blurring the boundaries a bit himself. I found the comments about my favorite animal, the zebrafish, a bit troubling. He arbitrarily decided that the criterion for the phylotypic stage in fish was the tailbud stage, the time when the tail first extends off the yolk. This is a criterion that excludes comparison with the chick, for instance, and also causes serious problems for comparisons with teleosts. Zebrafish develop remarkably rapidly, and have a relatively small yolk. The tail buds early, well before the pharyngula stage. That means he looked at zebrafish at this stage and claimed they lacked branchial arches altogether! Just six hours later, though, this animal would have a very nice collection of pharyngeal structures. He has done this for all of these animals: defined some specific criterion for the phylotypic stage, looked at the animals at this one time point, and found variation in certain features. This is fine for demolishing the accuracy of Haeckel's figures. It is *not* good for revealing fundamental homologies between these animals. Chicks do not have just two pharyngeal arches, except at the particular stage Richardson restricted himself to. Zebrafish do not lack arches: they have a very lovely set of six pairs...just not at that one particular time.

He is perfectly correct in showing that the explicit similarities implied in Haeckel's drawings are false. However, note that he does not call Haeckel a fraud in that paper -- what he suggests is that Haeckel was drawing a *stylized* (his word) rendering of the animals. Haeckel was blurring together stages and features to try and put together a stylized composite...admittedly exaggerating and deleting features to fit his thesis. That was wrong. He was caught in it, too, over a hundred years ago.

I think, though, that Richardson has gone too far the other way. He seems to be demanding near-photographic resemblance at a single narrowly defined point in development. That is just too restrictive a demand, and conceals the underlying similarity. I can't think of a single vertebrate embryo that lacks pharyngeal arches; that's too important and universal a feature to deny its significance by saying they don't all have precisely five arches at the same time that they have a tailbud.

There is one final irritation in that paper. Richardson claims that the persistence of the 'myth' of the phylotypic stage is in part due to the fact that so few people actually look at comparative embryology. I would turn that around and accuse him of a rather narrow-minded perspective on comparative embryology. I've done a fair amount of vertebrate embryology, but I've also got several years of work in arthropod development, and have spent a fair amount of time studying marine biology. One reason I can look at Figure 10 and see the huge similarities is that I've also looked at insect and crustacean and annelid and mollusc and echinoderm embryos -- and boy, they don't look nothin' like those chordates at *any* time.

Thursday, March 08, 2007

They Like Us, They Really Like Us!

 
BBC News has just published their World Service Poll.
The poll asked 28,000 people in 27 countries to rate a dozen countries plus the EU in terms of whether they have a positive or negative influence.

Canada, Japan and the EU are viewed most positively in the survey.
The competition wasn't too tough 'cause Australia wasn't even in the running. The battle between Canada and Japan was neck and neck until the last round when they counted the absentee ballots from Florida. There are a lot of Canadians in Florida at this time of year.

Canada and Japan had identical "mainly positive" votes but Canada wins first place because it had fewer "mainly negative votes." Tough luck, Japan, maybe next year.

The USA beat out North Korea, Iran, Venezuela, and Russia. Way to go USA! You're number 8! You're number 8!

Jennifer Smith Is Going to Meet Stéphane Dion

 
You remember Jennifer Smith, don't you? She lives in Milton, Ontario. That's the place made famous by PZ Myers 'cause he stopped for a few days to get his car fixed.

Well, it turns out that Jennifer went to a town hall meeting with her MP, the newly Liberalized Garth Turner. During the meeting she so impressed her MP that he invited her to meet with our future Prime Minister next week [All Politics Are Local]. (That's Dion in the picture, with his dog Kyoto.)

Hey, Jennifer, ask him if he'll increase reseach funding when we elect him next Fall.

The Low-Fat Diet Flunks Another Test

 
The title comes from an article by John Tierney on his blog [Tierney Lab: Putting Ideas in Science to the Test].

It's not really news. Low-fat diets have been challenged for years. There is good evidence that the Atkins diet really works for some people and it's healthy. Tierny gives us a quotation from a recent New York Times article that reported on a massive study recently completed.
The largest study ever to ask whether a low-fat diet reduces the risk of getting cancer or heart disease has found that the diet has no effect.

The $415 million federal study involved nearly 49,000 women ages 50 to 79 who were followed for eight years. In the end, those assigned to a low-fat diet had the same rates of breast cancer, colon cancer, heart attacks and strokes as those who ate whatever they pleased, researchers are reporting today.

‘’These studies are revolutionary,'’ said Dr. Jules Hirsch, physician in chief emeritus at Rockefeller University in New York City, who has spent a lifetime studying the effects of diets on weight and health. ‘’They should put a stop to this era of thinking that we have all the information we need to change the whole national diet and make everybody healthy.'’
All studies on human diets and nutrition are suspect, in my opinion. It's just the nature of the game. There are always contradictory results.

I'm not going to say that fat is never bad for you. What I say is that you should be skeptical about all claims concerning diet and health. They all need to be taken with a grain of salt (and a pound of steak ). Whenever you hear someone claiming to have all the answers you can dismiss them without a second thought. Nobody has the answers in this field, and that includes Professors, scientists, and physicians.

Intelligent Design Creationism and the History of Life

 
Denyse O'Leary repeats a common criticism of evolution over on Post-Darwinist [Response to student: Darwinian evolution not random?/ ID is God of the Gaps?].
On the face of it, Darwinian evolution is highly improbable or impossible on mathematical grounds. I mean that the history of complex life on earth (600 mya?) does not likely give us the resources we need for the random mutations. Once the Big Bang theory made it possible to establish an age for the universe (approx 13 bya) and the Earth (approx 4 bya), Darwinism was certain to come under attack.
600 million years is more than enough time for complex single-celled organisms to evolve mechanisms of associating to form complex multicellular organisms. This probability argument is just fancy hand-waving designed to impress the uninformed. (The fact that it's also made by the uninformed is ironic, but not surprising.)

But the real hypocrisy of the intelligent design creationist (IDC) community is in not coming up with a better explanation. Here's your big chance, Denyse. Why not give us a thumbnail sketch of how intelligent design creationism explains the fossil record of animals over the past 600 million years? While you're at it, you might throw in a brief description of how IDC accounts for the genetic data. You know, the genetic data that shows a perfectly reasonable rate of random mutations?

None of the IDiots have ever done this. They rant and rave about how improbable evolution is but they never give us an alternative that explains the facts. Why is that?

I'll make it real easy for you, Denyse. You don't have to explain everything. I'll be quite satisfied if the intelligent design creationists can give me their version of shark evolution. You can start with the separation of bony fish from cartilagenous fish about 450 million years ago. How did God do this? Why did He do it?

You can explain the appearance of Orthacanthus about 250 million years ago and why they look so similar to the species that lived a few million years earlier. Then you can tell us why God waited until 155 million years ago before creating the lamnoids that gave rise to modern looking sharks like the big white shark. Along the way, we eagerly await your explanation for why so many of those species are no longer with us. Did God get angry with them or does he just discard them as useless junk whenever He gets around to updating the latest model?

Here's a cladogram to help you out. When can we expect a response?


Science Blogging and Podcasts

 
Hsien Hsien Lei at Genetics & Health is experimenting with podcasts. She's figured out how to put a podcast on her blog. This is impressive. I haven't been able to do it ... yet.

See the result at Genetics and Health Podcast - Reflecting On My Role. I'm looking forward to more podcasts and to seeing how the experiment plays out.

UPDATE: I'm going to try and embed a podcast. Here's the Nature podcast from March 1, 2007 (I hope).


powered by ODEO

CBC

Wednesday, March 07, 2007

Canada .... hmmmm

 
You have to watch it right to the end ..... I don't know whether to laugh or cry (it's pretty funny).



[Hat Tip: Canadian Cynic]

Fairy Rings

 
I look at the botany photo of the day every day. This is a service provided by the Botanical Gardens at the University of British Columbia and I really appreciate their attempt to wean us away from animals.

Usually the photographs are spectacular closeup images taken with cameras that are much more expensive than mine. But yesteday's picture was from Google Earth! It shows 100 year old fairy rings near Kensington Palace in central London. The rings are probably caused by Marasmius oreades. Find out how a little fungus can make rings visible from so high.

Innocent Man Released from Jail

 
Mahmoud Jaballah is called a "terrorism suspect." He has been in jail for five years but he's never been found guilty of anything. That means he's an innocent man according to my sense of justice and he'll remain innocent until proven guilty.

Yesterday he learned that he will soon be released. Today's Toronto Star has the story [Terror suspect ordered freed].
Toronto terrorism suspect Mahmoud Jaballah will be released on strict bail conditions after more than five years in jail without charges, despite government protests he remains a danger to Canada.

His release comes on the heels of last month's Supreme Court ruling that struck down an immigration law as unconstitutional and deals another blow to the government's handling of security cases involving non-citizens.

Yeast Mitochondria

 
There's a paper in this month's issue of Developmental Cell that uses the technique of electron tomography to examine the fine structure of a yeast cell. This technique involves slicing the cell into many thin sections then taking electron micrographs of each section and reconstructing a three-dimensional model of the cell.

The species is the fission yeast Schizosaccharomyces pombe and the results are spectacular. The image on the left was part of the Bio News Net press release.

The emphasis in the paper is on the organization of microtubules. Those are the thin green lines runing down the length of the cell. It turns out that many of the vesicles and mitochondria are associated with these microtubules. Here's the abstract of the paper ..
Polarized cells, such as neuronal, epithelial, and fungal cells, all display a specialized organization of their microtubules (MTs). The interphase MT cytoskeleton of the rod-shaped fission yeast, Schizosaccharomyces pombe, has been extensively described by fluorescence microscopy. Here, we describe a large-scale, electron tomography investigation of S. pombe, including a 3D reconstruction of a complete eukaryotic cell volume at sufficient resolution to show both how many MTs there are in a bundle and their detailed architecture. Most cytoplasmic MTs are open at one end and capped at the other, providing evidence about their polarity. Electron-dense bridges between the MTs themselves and between MTs and the nuclear envelope were frequently observed. Finally, we have investigated structure/function relationships between MTs and both mitochondria and vesicles. Our analysis shows that electron tomography of well-preserved cells is ideally suited for describing fine ultrastructural details that were not visible with previous techniques.
One of the most interesting things about this paper is that it illustrates the structure of mitochondria. Look at the picture on the right from their paper. The gold things are mitochondria and they appear to be stuck to microtubules. Individual mitochondria are shown in the inserts in order to illustrate the convoluted and branching structures of those that are associated with microtubules. (The one labelled "G" is not stuck to microtubules.)

Most people don't realize that mitochondria are so complicated. Furthermore, the structures are dynamic—they can change significantly in the space of minutes.
Höög, J.L., Schwartz, C., Noon, A.T., O'Toole, E.T., Mastronarde, D.N., McIntosh, J.R., and Antony, C. (2007) Organization of Interphase Microtubules in Fission Yeast Analyzed by Electron Tomography. Developmental Cell 12: 349-361.

James Randi and Richard Dawkins

 
It's a shame when you get two smart people like this on the same stage and all you get are banalities. The audience must have been very disappointed.

Nobel Laureate: Paul Hermann Müller

 
The Nobel Prize in Physiology or Medicine 1948.

"for his discovery of the high efficiency of DDT as a contact poison against several arthropods"


Paul Hermann Müller won the Nobel Prize in 1948 for is discovery that DDT was an effective insect poison [see Monday's Molecule #16 and DDT Blocks the Voltage-Gated Sodium Channel]. Müller was looking for a contact poison that would protect plants from insects. He extended the work of others who discovered compounds that could be applied to wool to prevent them from being ruined by moths. These compounds resembled DDT but they were not as effective. Müller's approach is described in the presentation speech ...
Paul Müller went his own way and tried to find insecticides for plant protection. In so doing he arrived at the conclusion that for this purpose a contact insecticide was best suited.

Systematically he tried hundreds of synthesized organic substances on flies in a type of Peet-Grady chamber. An article by the Englishmen Chattaway and Muir, gave him the idea of testing combinations with the CCl3 groups, and this then finally led to the realization that dichloro-diphenyl-trichloro-methylmethane acted as a contact insecticide on Colorado beetles, flies and many other insect species under test. He determined its extraordinary persistence, and simultaneously developed the various methods of application such as solutions, emulsions and dusts.

In trials under natural conditions Müller was able to confirm the long persistent contact action on flies, Colorado beetles and gnats (Culex).
Subsequent work revealed that DDT was effective against a wide variety of insects and was harmless to mammals. Among the insects that were killed by DDT were lice, the carriers of thyphoid, and malaria mosquitos.

At the time, Müller was working for the J.R. Geigy Dye-Factory Co. in Basel Switzerland and he had given samples of DDT to the Swiss Army for testing. The results demonstrated that insect borne diseases could be controlled by DDT.
At that time, the Allied Armies of the West were struggling with severe medical problems. A series of diseases transmittable by insects, diseases such as typhus, malaria and sandfly fever claimed a large number of victims and interfered with the conduct of the War. The Swiss, who had recognized the great importance of DDT, secretly shipped a small quantity of the material to the United States; in December of 1942 the American Research Council for Insectology in Orlando (Florida) undertook a large series of trials which fully confirmed the Swiss findings. The war situation demanded speedy action. DDT was manufactured on a vast scale whilst a series of experiments determined methods of application. Particularly energetic was General Fox, Physician-in-Chief to the American forces.

In October of 1943 a heavy outbreak of typhus occurred in Naples and the customary relief measures proved totally inadequate. General Fox thereupon introduced DDT treatment with total exclusion of the old, slow methods of treatment. As a result, 1,300,000 people were treated in January 1944 and in a period of three weeks the typhus epidemic was completely mastered. Thus, for the first time in history a typhus outbreak was brought under control in winter. DDT had passed its ordeal by fire with flying colours.
By the late 1950's it became apparent that extensive use of DDT to control insects leads to its accumulation in the environment. This, in turn, leads to its concentration in the tissues of some animals, such as fish. The long term build up of DDT causes illness and death and it was finally banned in most countries in the 1970's.

Tuesday, March 06, 2007

Alcoholics Anonymous: 12 Steps

 
This month's reader's Digest has a couple of articles on Alcoholics Anonymous. The gist of the articles is that the famous 12 steps really don't work all that well. Apparently, there's no data to support the claim that Alcoholics Anonymous is successful at getting people to stop drinking.

I had no idea what these 12 steps were until they were published in the articles I read yesterday. For those of you who don't know, here they are [Alcoholics Anonymous]. I'm not surprised that this isn't a magic bullet but I am surprised at how religious AA must be. They must think that most alcoholics are Christians.
THE TWELVE STEPS
OF ALCOHOLICS ANONYMOUS
  1. We admitted we were powerless over alcohol ラ that our lives had become unmanageable.
  2. Came to believe that a Power greater than ourselves could restore us to sanity.
  3. Made a decision to turn our will and our lives over to the care of God as we understood Him.
  4. Made a searching and fearless moral inventory of ourselves.
  5. Admitted to God, to ourselves and to another human being the exact nature of our wrongs.
  6. Were entirely ready to have God remove all these defects of character.
  7. Humbly asked Him to remove our shortcomings.
  8. Made a list of all persons we had harmed and became willing to make amends to them all.
  9. Made direct amends to such people wherever possible, except when to do so would injure them or others.
  10. Continued to take personal inventory and when we were wrong promptly admitted it.
  11. Sought through prayer and meditation to improve our conscious contact with God, as we understood Him, praying only for knowledge of His will for us and the power to carry that out.
  12. Having had a spiritual awakening as the result of these steps, we tried to carry this message to alcoholics, and to practice these principles in all our affairs.