Facts, not Fantasy

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Wednesday, September 30, 2009

Evolution Bonanza

Today I am going to link to quite a few articles to catch up on some of the news since last time I made an entry. Although, if you click the title of this blog entry, it will bring you to the main page of Science Daily's evolution news. There's A LOT of stuff there to read. Some highlights:

Feathery Four-winged Dinosaur Fossil Found In China Bridges Transition To Birds. A fossil of a bird-like dinosaur with four wings has been discovered in northeastern China. The specimen bridges a critical gap in the transition from dinosaurs to birds, and reveals new insights into the origin evolution of feathers. The transition from dinosaurs to birds is poorly understood because of the lack of well-preserved fossils, and many scientists argue that bird-like dinosaurs appear too late in the fossil record to be the true ancestors of birds.

Scandinavians Are Descended From Stone Age Immigrants, Ancient DNA Reveals. Today's Scandinavians are not descended from the people who came to Scandinavia at the conclusion of the last ice age but, apparently, from a population that arrived later, concurrently with the introduction of agriculture. This is one conclusion of a new study straddling the borderline between genetics and archaeology, which involved Swedish researchers and which has now been published in the journal Current Biology. "The hunter-gatherers who inhabited Scandinavia more than 4,000 years ago had a different gene pool than ours," explains Anders Götherström of the Department of Evolutionary Biology at Uppsala University, who headed the project together with Eske Willerslev of the Centre for GeoGenetics at the University of Copenhagen.

Getting A Leg Up On Whale And Dolphin Evolution: New Comprehensive Analysis Sheds Light On The Origin Of Cetaceans. When the ancestors of living cetaceans—whales, dolphins and porpoises—first dipped their toes into water, a series of evolutionary changes were sparked that ultimately nestled these swimming mammals into the larger hoofed animal group. But what happened first, a change from a plant-based diet to a carnivorous diet, or the loss of their ability to walk? A new paper published this week in PLoS ONE resolves this debate using a massive data set of the morphology, behavior, and genetics of living and fossil relatives. Cetacean ancestors probably moved into water before changing their diet (and their teeth) to include carnivory; Indohyus, a 48-million year-old semi-aquatic herbivore, and hippos fall closest to cetaceans when the evolutionary relationships of the larger group are reconstructed.

First Evolutionary Branching For Bilateral Animals Found. When it comes to understanding a critical junction in animal evolution, some short, simple flatworms have been a real thorn in scientists’ sides. Specialists have jousted over the proper taxonomic placement of a group of worms called Acoelomorpha. This collection of worms, which comprises roughly 350 species, is part of a much larger group called bilateral animals, organisms that have symmetrical body forms, including humans, insects and worms. The question about acoelomorpha, was: Where do they fit in? To scientists, acoelomorpha, has been enigmatic, a “rogue animal,” said Casey Dunn, an evolutionary biologist at Brown University. “It has been wandering throughout the animal tree of life.”

Mutations Make Evolution Irreversible: By Resurrecting Ancient Proteins, Researchers Find That Evolution Can Only Go Forward. A University of Oregon research team has found that evolution can never go backwards, because the paths to the genes once present in our ancestors are forever blocked. The findings -- the result of the first rigorous study of reverse evolution at the molecular level -- appear in the Sept. 24 issue of Nature. The team used computational reconstruction of ancestral gene sequences, DNA synthesis, protein engineering and X-ray crystallography to resurrect and manipulate the gene for a key hormone receptor as it existed in our earliest vertebrate ancestors more than 400 million years ago. They found that over a rapid period of time, five random mutations made subtle modifications in the protein's structure that were utterly incompatible with the receptor's primordial form.

Molecular Evidence Supports Key Tenet Of Darwin's Evolution Theory. An international team of researchers, including Monash University biochemists, has discovered evidence at the molecular level in support of one of the key tenets of Darwin's theory of evolution. Monash University's Professor Trevor Lithgow said the breakthrough, funded by the Australian Research Council and published recently in the journal Proceedings of the National Academy of Sciences, provides a blueprint for a general understanding of the evolution of the "machinery" of our cells. "Our cells, and the cells of all organisms, are composed of molecular machines. These machines are built of component parts, each of which contributes a partial function or structural element to the machine. How such sophisticated, multi-component machines could evolve has been somewhat mysterious, and highly controversial." Professor Lithgow said.

Mechanism That Constructs Key Brain Structure Discovered. Yale University researchers have found a molecular mechanism that allows the proper mixing of neurons during the formation of columns essential for the operation of the cerebral cortex, they report in the Sept. 16 online issue of the journal Nature. Scientists have known for years that information processing in the cerebral cortex depends upon groupings of neurons that assemble in the shape of vertical columns. If the number and mix of neurons in the column are wrong, severe cognitive problems can result. For instance, malformations of these columns have been implicated in some forms of autism and mental retardation. Scientists, however, have not been able to find the molecular mechanism responsible for this intermixing.

Dr. Plait Update:
I’m leaving, on a jet plane… but I do know when I’ll be back again. But between now and then I’m off to jolly old to attend TAM London! So this is a short post designed to buy me a few hours.
1) Remember the homeopath and his wife who killed their nine-month-old daughter, because she had severe eczema and all they did was give her nothing but water (because that’s what homeopathic "medicine" is)? Yeah, they got six years in jail.

2) Antivax groups aren’t getting smarter about medicine, but they are getting smarter about branding. They call themselves Talking About Curing Autism and Operation Rescue, but don’t be fooled: they are antivaccination, pure and simple. And whether they believe what they say or not, they are not supporting children. They are putting them at grave risk of illness and death from preventable diseases.
Worse, if you read that link you’ll see that TACA is sponsoring a concert to raise funds for their antivax efforts, and got the radio station JACK 93.1 to partner with them. Lots of big names will be at the concert, and all the money will go toward a group that may in fact want to help autistic kids, but is also spreading gross misinformation about vaccines while doing it.

3) And finally, a ray of hope: the New York Times posted an article debunking antivax swine flu nonsense. Yay!

Girl dies shortly after vaccine shot

That headline above is factually accurate. Of course, most people reading it will assume that the vaccination caused the death. But we have no evidence of that yet, so try not to jump to conclusions.

The Daily Mail is reporting that a young woman, aged 14, died shortly after receiving a vaccine shot (they call them "jabs" in the UK) for HPV, to prevent cervical cancer. They are reporting that about an hour after the shot she became pale, stopped breathing, and fainted. Rescuers were not able to save her.

This story, first and foremost, is horrible and tragic. My heart goes out to the parents of the young woman and to all her friends and schoolmates. This is an awful thing, what every parent dreads.

I want to be careful and not rush to judgment, though. First and foremost, we don’t know that the vaccination is why she died. The Daily Mail is not exactly the most trusted news source, to start off with. I am taking events reported therein with a large grain of salt.

Second, we don’t know why she died at all. Reports of that have not yet been aired.

Third, complications of any kind from vaccinations are incredibly rare. Gardasil, an HPV vaccination (though different than the one the girl in England received), has been given to over 7 million girls, yet there have been only 20 deaths after getting the shot… and for almost all of them there is no obvious relation between the shot and the fatality except for timing. In other words, they were tragic coincidences.

As one person pointed out on Twitter, you could write an article that says "Man dies after reading the Daily Mail", since I’m sure that will happen many times every day.

As skeptics tirelessly point out: correlation does not mean causation. Because an event happens after a previous event, it doesn’t mean the first caused the second. Is it possible the vaccination resulted in that girl’s death? Yes, it’s possible. However, was it responsible? That we don’t know, and have to wait.

And if it was responsible, we need to find out why. Did she have a rare condition? Was it a bad batch? Was she terribly scared of shots, and her heightened fear exacerbated a heart condition? The point is, we don’t know.

What I do know is that the antivax crowd will go ballistic over this, despite not having enough facts to make a rational conclusion here. But facts are tenuous or malleable things to them, only useful for ignoring or distortion.

In the comments below I expect we’ll hear a lot of the usual misinformation about toxins and autism and mercury and fetal tissue, long-debunked worries over vaccines. Let’s please remember two things here: one is that we don’t know what happened, and the other is that a young girl has died, and we should all be respectful of that.

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