The Arithmetic of Souls

December 29, 2006

(A continuation of the oh-so-controversial “Souls on Ice” post I made back in October.)

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The Speed of Meme

November 28, 2006

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A blogger over at Acephalous is doing a pop science experiment to measure the speed of a meme. As a student of social science, I am dutifully linking to the original article. Besides duty, there’s the interesting educational opportunity (though I’m not convinced that the ‘experiment’ will yield any usable data other than increasing Acephalous’s traffic), and the fact that “acephalous” has to be one of the funniest blog titles I’ve seen so far.

If you don’t already know, a meme is a “unit of cultural information transferable from one mind to another.” The term was coined by Richard Dawkins (the famous evolutionary biologist who recently wrote the bestseller The God Delusion, which I still haven’t read) and is intended to be analagous to the gene, which is the unit of selection in biological evolution (at least according to most evolutionary biologists- I’m currently reading Dawkins’ The Selfish Gene on this very subject).

From Wikipedia:

“Richard Dawkins introduced the term after writing that evolution depended not on the particular chemical basis of genetics, but only on the existence of a self-replicating unit of transmission — in the case of biological evolution, the gene. For Dawkins, the meme exemplifies another self-replicating unit, and most importantly, one which he thought would prove useful in explaining human behavior and cultural evolution.”

(On a side note, the picture above illustrates the linkings between webpages, and is from a page with interesting illustrations of different types of networks.)

The most prolific memes are probably the ones we don’t even notice. And of course, the concept of memes has proven to be a rather prolific meme, likely due to its flexibility and broad application. Pretty much anyone can make some sort of point using the concept of memes. Like this post.


You Are Here (The Circle of Phylogenetics)

November 26, 2006

Phylogenetics is the study of the relatedness of organisms. In other words, scientists look at physical traits (morphology) and (more recently) DNA sequences to determine which organisms have more in common that others. Even if you’ve never heard of phylogenetic taxonomy before, you’re already familiar with some basic separations, such as between animals and plants. The Tree of Life has some nice illustrations, but I thought this circular phylogenetic tree was especially cool:

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This circular tree, which was published in Science, Shows relationships between representatives of all species on Earth. It was developed by David M. Hillis, Derrick Zwickl, and Robin Gutell at the University of Texas. As they state on their website (where the full pdf file is available- a really cool thing to zoom in and out on!) the tree is:

“an analysis of small subunit rRNA sequences sampled from about 3,000 species from throughout the Tree of Life. The species were chosen based on their availability, but we attempted to include most of the major groups, sampled very roughly in proportion to the number of known species in each group (although many groups remain over- or under-represented). The number of species represented is approximately the square-root of the number of species thought to exist on Earth (i.e., three thousand out of an estimated nine million species), or about 0.18% of the 1.7 million species that have been formally described and named.”

Here’s a closeup of the Animals section:
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The arrow below points to humans:

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And one final zoom in:

This reminds me of a quote from Tim Rice that ended up in my Developmental Biology textbook:

“It’s the circle of life, and it moves us all.”


Concerning the Beast Folk

November 22, 2006

On a recent visit to Barnes & Noble (this literary addiction is getting rather expensive) I browsed through a stack of compilations of novels by famous authors. One caught my eye: a collection of works by H.G. Wells. It includes the Time Machine, War of the Worlds, and The Island of Dr. Moreau, all of which I’ve been meaning to read, so I found it a new, loving home–my bookshelf.

 

The Island of Dr. Moreau got inexplicably bumped to the top of my reading queue, probably because I was craving something fictional. I saw the movie adaptation some years ago, and had vague memories of it being creepy, scary and disgusting.

 

The basic premise is that Prendick, passenger on a sea voyage, is shipwrecked on an island occupied by the namesake physiologist and his assistant. The only other residents of the island, as the narrator eventually discovers, are monstrous human/animal hybrids.

 

Dr. Moreau was a prominent physiologist in London who was eventually driven away from respectable society by his methods, including his disregard for the pain caused by his experiments. Dr. Moreau moved shop to his island, where he was free to take all manner of beast and shape them into human form.

 

While the science is assuredly outdated in ways, Dr. Moreau’s reality has a potential to become ours. Whole segments of one embryo can be grafted onto another of a different species during development, and many of the results can be both surprisingly revolting and survivable.

 

Our pursuit of cures for genetic diseases in humans will inevitably lead to an ability to alter specific genes for the sake of improvements, not just treatments. (Some, such as members of the transhumanist movement, openly advocate improving the human species in this way.) Surely someone will also realize the benefit of inserting genes for the production of human insulin, antibodies, or blood into a primate. Or what about using animals to grow replacement human organs?

 

Not many are openly calling for the creation of more grotesque human/animal chimeras, but as the ability to perform such experiments becomes more diffuse, it is nearly inevitable that someone will eventually attempt it. So we are left with the question of how we will regard these creations. Fully animal? Partly human?

 

For now, I’ll leave you with some rather disturbing diatribes by Dr. Moreau:

“So long as visible or audible pain turns you sick, so long as your own pains drive you, so long as pain underlies your propositions about sin, so long, I tell you, you are an animal, thinking a little less obscurely what an animal feels.”

“Then I am a religious man, Prendick, as every sane man must be. It may be I fancy I have seen more of the ways of this world’s Maker than you—for I have sought his laws, in my way, all my life. While you, I understand, have been collecting butterflies. And I tell you, pleasure and pain have nothing to do with heaven or hell. Pleasure and pain—Bah! What is your theologian’s ecstasy but Mahomet’s houri in the dark? This store which men and women set on pleasure and pain, Prendick, is the mark of the beast upon them, the mark of the beast from which they came.”

“To this day I have never troubled about the ethics of the matter. The study of Nature makes a man at last as remorseless as Nature.”

For the record, I don’t recommend Moreau’s ethics or theology. But bravo to Mr. Wells: good novel, nice concept, and interesting dilemmas. I think I’ll have to watch that movie again and see what I think now.


Gentlemen, we can rebuild them. We have the technology.

November 16, 2006

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Well, not exactly. But if we can sequence the human genome (in record time and underbudget, thanks Mr. Collins), why not the Neanderthals genome too?

There have been some big potential holdups. First, there’s the problem that they’re extinct. And then the fact that genomes start degrading right away. And that 95% of the DNA recovered from Neanderthal bones is bacterial DNA. And most Neanderthal bones that have been recovered are hopelessly contaminated by the DNA of the humans who found them.

But new advances in technology appear poised to overcome what used to be seen as insurmountable obstacles (a recurring theme in the biological sciences). The New York Times reports that scientists at the Max Planck Institute in Germany are using a new technique that can combine small fragments of ancient DNA (usually under 100 base pairs in length) into complete genomes.

The process filters out bacterial DNA and slowly pieces together the larger genome. It’s been used on ancient cave bears and mammoths, but the application to Neanderthals would shed light on a particularly controversial area of scientific investigation; whether Neanderthals are direct human ancestors or merely a related line that died off (or that we out-competed or killed off).

Sequencing the Neanderthal genome (which at ‘first glance’ is 99.5% identical to human, whereas chimpanzees are at least 95% identical genetically) will give us better evidence on the question of whether humans crossbred with Homo neanderthalensis, picking up important genes along the way, or simply displaced Neanderthals in Europe around 35,000 years ago. While most scientists seem to agree that there is no hard evidence for crossbreeding, not everyone agrees.

Some scientists have recently asserted (in the Proceedings of the National Academy of the Sciences) that humans picked up an important gene (microcephalin, MCPH1) necessary for brain development from Neanderthals.

One reason this research will be so fascinating to follow is that the relation of Homo sapiens (us) to Homo neanderthalensis (them) is anything but certain. Neanderthals (see Wikipedia) had tools, likely had language (their hyoid bone was nearly identical to ours), buried their dead, constructed complex shelters, controlled fire, and possibly even made rudimentary musical instruments.

So what we Neanderthals really like? Only time (and good genome sequencing technology) will tell.


Souls on Ice

October 19, 2006

I just finished reading a fascinating (though lengthy) article on the fate of embryos called Souls on Ice: America’s Embryo Glut and the Wasted Promise of Stem Cell Research. This ties in well to some things we’ve been discussing into my (occasionally though not usually) enlightening course on medical ethics.

In brief, the article discusses how the massive use of fertility treatments like in vitro fertilization have led to the existence of thousands of frozen embryos– more than will ever be implanted, gestated, and born. There are only a few options for embryos: implantation, indefinite freezing, destruction through thawing, or destruction through medical research.

Many people who did not hesitate to undergo in vitro fertilization procedures now hesitate to donate their frozen embryos for research, and those embryos are accumulating in warehouses… somewhere. And embryonic stem cell research, contrary to some popular belief I’ve encountered, is not illegal. Rather, Bush vetoed federal funding for embryonic research (excepting a few pre-existing lines), but several states and many universities have procured other sources of funding to make up for the shortfall.

As for the ethics of it all, one of the weakest arguments Christians make for not pursuing embryonic stem cell research (and this one was made to me within the last week) is that somatic stem cells can be used for everything that embryonic stem cells can be used for. This is ludicrous as stem cells are by definition more pluripotent than somatic stem cells. In other words, embryonic stem cells removed early in development can differentiate into many types of tissue that somatic stem cells removed from adults simply cannot.

Another flawed argument often presented goes thus: “There are absolutely no medical applications from embryonic stem cell research.” Reply: Of course not- there hasn’t been much of it. In the 1950’s no one used the argument “there are absolutely no medical applications for DNA research” because there simply wasn’t a state of knowledge available that would lead to viable therapies. Seriously, why would many of the premiere medical researchers be publicly bemoaning the federal funding ban if embryonic stem cells were really nothing new?

The strong arguments against stem cell research are based on the moral status of the embryo. If an 8- or 16-cell embryo has the same moral value as an adult human, then pursuing embryonic stem cell research is tantamount to murder. In fact, these arguments are compelling and unavoidable if one believes the Bible is the word of God.

Of course, these arguments are only strong if one agrees with conservative Christians that the early embryo is of the same moral value as an adult- a conclusion not reached by many secular ethicists and liberal Christians with a less strict application of Biblical precepts to modern existence.

While I believe embryos are worthy of respect, I don’t assign them the same moral worth as myself, or someone dying of a possibly curable disease. In other words, destroying them needlessly would be wrong, as they represent potential human beings. But the needs of fully conscious humans with full personhood should not be secondary to an 8-cell blastocyst that no one has a problem with freezing. And I will continue to hope that embryonic stem cell research will be one area in the “culture war” where conservative Christians won’t succeed, because that triumph could hurt us all. Read the rest of this entry »