The Trichoplax Genome

 
Trichoplax adherens is a very simple animal that moves about on surfaces like a gigantic amoeba and ingests any food that it flows over. There are thought to be several species of Trichoplax in addition to Trichoplax adherens.

Because this is such a simple and unusual animal it has been assigned its own phylum, Placozoa with Trichoplax as the only genus.¹

The diagram below is copied from Syed and Shierwater (2002). It shows clearly that Trichoplax adhaerens is a true metazoan with an upper (dorsal) epithelial layer, a lower (ventral) epithelial layer, and an internal layer of contractile fiber cells. There are at least four cell types, not counting the egg and sperm cells that have been reported by others.


Where does Trichoplax fit in the evolution of animals? Clearly, the lineage leading to modern Trichoplax must have diverged very early in animal evolution. This is why Trichoplax is often (incorrectly) referred to as a "primitive animal", or a "living fossil." (See Ryan Gregory's discussion of this terminology at: Kudos on the placozoan genome!.)

The exact branch point is hotly disputed. Did the ancestors of Trichoplax split off before or after the sponges (Porifera) or the Cnideria (jelleyfish, hydras, corals)? Is the modern form of Trichoplax the ancestral form or is it a derived and simplified version of a more complex animal?



The complete genome sequence of Trichoplax adherens has just been published in Nature (Srivastava et al. 2008). There's a pretty good press release on Bio News Net [Genome of simplest animal reveals ancient lineage, confounding array of complex capabilities]. In addition to Ryan Gregory's review, there's another by John Timmer at Nobel Intent (Ars Technica) [Sequencing the bizarre: the genome of a living fossil].

Trichoplax adherens has six chromosomes and a total genome size of about 98 × 10⁶ base pairs (98 Mb). The authors identified 11,514 protein-encoding genes. Because the genome sequence is "only" 98% complete, it wasn't possible to reconstruct entire chromosomes and the association between the sequenced genome and particular chromosomes is impossible to establish due to the absence of genetic studies on Trichoplax (no linkage maps).

The genome is smaller than that of the green alga Chlamydomonas reinhardtii with a genome of 121 Mb and about 15,000 genes [The Genome of Chlamydomonas reinhardtii]. On the other hand, the Trichoplax genome is larger than that of other single-cell organisms such as the protist Giardia lamblia (12 Mb, ~6500 genes) [The Giardia lamblia Genome].

The Trichoplax genome is almost the same size as the C. elegans (nematode) genome at 97 Mb but C. elegans is thought to have more than 15,000 genes. Drosophila melanogaster at 180 Mb has ~16,000 genes and mammals have a genome of 3,300 Mb and 20,000 genes.

About 90% of the Trichoplax genes are present in other animals and the intron positions of the Trichoplax are mostly identical to those in other animals [Junk in Your Genome: Intron Size and Distribution]. This is powerful evidence that the phylum Placozoa belongs in the animal kingdom.

Srivastava et al. constructed a phylogenetic tree using 104 highly conserved genes from species whose complete genomes are available in the sequence databases. The tree (below) shows that the Trichoplax lineage branches after sponges (represented by Amphimedon queenslandica) but before cnidarians (Hydra magnipapillata). The result are not compatible with trees constructed using mitochondrial sequences or ribosomal RNA sequences but that's not too surprising. Mitochondrial DNA and ribosomal RNA sequences are often not reliable for this kind of work.


The conclusion is that Placozoa and most metazoans diverged about 600 million years ago but sponges diverged even earlier.

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1. It isn't unusual to create separate phyla for organisms with distinct body plans but you wouldn't know that from the criticisms leveled at Stephen Jay Gould when he published Wonderful Life [Science and Philosophy Book Club: Wonderful Life]. Incidentally, in The Ancestor's Tale Dawkins readily accepts that Trichoplax adherens may be the sole species in the phylum Placozoa.

[Image Credit: The photograph of Trichoplax is from metamorphnet. That website also has some wonderful movies of Trichoplax.

Srivastava, M., Begovic, E., Chapman, J., Putnam, N.H., Hellsten, U., Kawashima, T., Kuo, A., Mitros, T., Salamov, A., Carpenter, M.L., Signorovitch, A.Y., Moreno, M.A., Kamm, K., Grimwood, J., Schmutz, J., Shapiro, H., Grigoriev, I.V., Buss, L.W., Schierwater, B., Dellaporta, S.L., Rokhsar, D.S. (2008) The Trichoplax genome and the nature of placozoans. Nature 454:955-960. [doi:10.1038/nature07191]

Gene Genie #35

 
The 35th edition of Gene Genie has been posted at Microbiology Bytes [Gene Genie 34: Summertime and the blogging is easy]. (This really is the 35th edition in spite of the title.)

Welcome to edition 34 of Gene Genie, the blog carnival of genes and genetic conditions.

It’s high summer, and the internet is a dead as a doornail, but a few diligent bloggers are still slogging away at the keyboard while everyone else is at the beach.

The beautiful logo was created by Ricardo at My Biotech Life.

The purpose of this carnival is to highlight the genetics of one particular species, Homo sapiens.

Here are all the previous editions .....

1. Scienceroll
2. Sciencesque
3. Genetics and Health
4. Sandwalk
5. Neurophilosophy
6. Scienceroll
7. Gene Sherpa
8. Eye on DNA
9. DNA Direct Talk
10. Genomicron
11. Med Journal Watch
12. My Biotech Life
13. The Genetic Genealogist
14. MicrobiologyBytes
15. Cancer Genetics
16. Neurophilosophy
17. The Gene Sherpa
18. Eye on DNA
19. Scienceroll
20. Bitesize Bio
21. BabyLab
22. Sandwalk
23. Scienceroll
24. biomarker-driven mental health 2.0
25. The Gene Sherpa
26. Sciencebase
27. DNA Direct Talk
28. Greg Laden’s Blog
29. My Biotech Life
30. Gene Expression
31. Adaptive Complexity
32. Highlight Health
33. Neurophilosophy
34. ScienceRoll
35. Microbiology Bytes

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Barbara King at Chautauqua

 
Barbara King is Professor of Anthropology at the College of William and Mary. Her specialty is primate behavior, especially gorillas. She spoke about how the non-human apes relate to each other and suggested that these relationships reveal the origins of religion. Here's how she describes it on her website.

My newest project has taken me in exciting new directions. My latest book (Evolving God, Doubleday, January 2007) explores the deepest roots of the human religious imagination. Although I definitely do not think apes are religious, I do think that the empathy and compassion and meaning-making shown by apes in the wild and in captivity points us towards clues for understanding the precursors of religion in our earliest hominid ancestors. I trace the evidence for religious, symbolic ritual throughout human prehistory, culminating in the burial rites and art of Neandertals and Homo sapiens.

I don't think it's an exaggeration to say that most people found her talk confusing. Her main point wasn't at all clear. Was she really arguing that non-human ape behavior might be a precursor of religion? Was she making a connection between religion and "empathy and compassion"? If so, what is the connection?

I bought her book, Evolving God: A Provocative View on the Origins of Religion but I haven't had a chance to read it. I thought it might be informative to find her definition of religion. Here it is (p. 18); "Almost certainly, the most widely used and cited definition was proposed by Clifford Geertz: religion is 'a system of symbols which acts to establish powerful, persuasive, and long-lasting moods and motivations in men by formulating conceptions of a general order of existence and clothing these conceptions with such an aura of factuality that the moods and motivations seem uniquely realistic.'"

No wonder most people found her talk confusing. Barbara King specifically notes that her definition of religion does not require "faith, belief, God, gods, spirits, eternal life, souls, or sacred texts."

The main beef I have with Barbara King's presentation comes from her response to a question from the audience. She was asked to describe her religious beliefs and she refused to do so, citing her confidence that her personal beliefs do not influence her science. I don't think that's acceptable in most science that make claims about religion but especially the field of anthropology. I think scientists have an obligation to lay their biases on the table and let outside observers judge whether such beliefs influence the work.

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Edward Larson at Chautauqua

 
Edward J. Larson is University Professor and Hugh & Hazel Darling Chair in Law at Pepperdine University. He has a law degree from Harvard and a Ph.D. in history from the University of Wisconsin-Madison.

Larson is a prolific writer. He is the author of seven books including Summer for the Gods: The Scopes Trial and America's Continuing Debate Over Science and Religion (1997) for which he received the 1998 Pulitzer Prize. Many of us know him for his more recent books, including Evolution: The Remarkable History of a Scientific Theory (2004) and The Creation-Evolution Debate: Historical Perspectives (2007).

Larson gave an interesting and informative talk about the evolution-creation controversy in America. His ideas about the real battle in the Scopes trial are very interesting. He claims that the main dispute was about the social implications of evolution and the conflict between science and religion has been overplayed—especially in the movie Inherit the Wind.¹

I've heard this before. William Jennings Bryan was a populist who thought that social Darwinism is what led to the First World War. He was afraid that teaching evolution in the schools would encourage social Darwinism. Of course, he was also religious and feared that evolution was a threat to religion.

For many in the audience the history of the trials was new information and Larson did a good job of explaining both the scientific issues and the legal ones. He cautioned the audience that things could deteriorate rapidly with only one or two changes on the Supreme Court.

Someone from the audience asked what would have happened if the Dover case had been appealed. Larson said he was confident that the decision would have been upheld at the district court but he's not so sure about the current Supreme Court. If he had to bet, he would put his money on the decision being upheld but he's not very confident.

The one thing that troubled me about his lecture was that he always referred to the conflict between creationism and the Theory of Evolution. My students picked up on this since I was emphasizing the differences between evolution as a fact and a theory. As most of you know, creationists are as much opposed to the facts of evolution as they are to evolutionary theory. It would be better, in my opinion, to refer to the conflict as a fight between creationism and the fact of evolution. To use the phrase "Theory of Evolution" seems to be catering to creationist misconceptions.

On Thursday afternoon the schedule called for a discussion with Diane Ackerman, the author of The Zookeeper's Wife. Unfortunately, Ackerman couldn't make it so Edward Larson filled in with a fascinating (according to Ms. Sandwalk) talk about his latest book A Magnificent Catastrophe: The Tumultuous Election of 1800. Apparently religion played an important role in that election with Jefferson being accused of lacking belief.

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1. The theater class took a course on the play Inherit the Wind. Apparently, the staging of the original play is remarkable. That group also discussed the differences between the real trial and the one in the play and the influence of McCarthyism. I wish I could have taken that course last week, and many others.

Monday's Molecule #85

 
This week marks the beginning of a new term at many colleges and universities in the USA. To mark the occasion, I've chosen a simple molecule that should be familiar to every undergraduate taking an introductory biochemistry course. Your task is to indentify the molecule and give me its correct common name—the one required on an exam—and the complete, correct IUPAC name.

There's a direct connection between today's molecule and a Nobel Prize. We are looking for the single person most responsible for identifying this molecule as part of a metabolic pathway. This person didn't know the exact structure but got the basic chemistry correct. Be careful, there are several possible candidates who haven't already been featured on Sandalk. I want the one person who best meets the criterion.

The first person to correctly identify the molecule and name the Nobel Laureate, wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first collected the prize. There are four ineligible candidates for this week's reward. You know who you are.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureate(s) so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow. I reserve the right to select multiple winners if several people get it right.

Comments will be blocked for 24 hours. Comments are now open.

UPDATE: This week's winner is Bill Chaney of the University of Nebraska. He correctly identified the molecule as β-D-fructofuranose 1,6- bisphosphate and he chose [(2R,3S,4S,5R) -2,3,4 -trihydroxy-5- (phosphonooxymethyl) oxolan-2-yl] methyl dihydrogen phosphate as the correct IUPAC name [but see IUPAC]. That's probably more information than we needed but Chaney was the first to reply (by several hours). The Noble Laureate is Arthur Harden.

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Check Your Irony Meters

 
John Lynch has a wonderful comment on the train wreck at Uncommon Descent. Read what DaveScot has to say about people who post comments without identifying themselves [Just another day of “discourse” for the peanut gallery].

Don't follow the links from John's postings unless you have a Mark VIII Irony Meter or better.

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Stephen Matheson's Critique of Michael Behe's Edge of Evolution

 
I've been meaning to write up my own critique of Michael Behe's latest book The Edge of Evolution but there always appear to be more important things to do. Stephen Matheson at Quintessence of Dust has posted a number of articles on the topic. You can find the links in his latest posting Why I'm not a Behe fan, Part IIB: abusing genetics.

I'm in complete agreement with Stephen on one thing ...

These clarifications are important, because much of the criticism of EoE has been botched significantly. The book is bad, really bad, but it can't be honestly characterized as an anti-evolution argument.

Many reviews of The Edge of Evolution are not as good as one might expect from scientists who have read the book.

Stephen Matheson gets the essence of Behe's argument so his review is much better than others. However, I'd like to comment on a few things he says ...

I. Behe's assumption of a particular mutation rate is both absurdly oversimplified and inappropriately extrapolated into the entire tree of life.

The basis of all of Behe's calculations is a mutation rate of 1 in 100 million. This is the estimated rate at which misspelling-type mutation occurs in each generation, averaged over the entire genome, in humans. (The number doesn't consider other types of mutation, now known to be more common than previously thought.) Behe uses this number in all of his (flawed) probability calculations. Even if we knew nothing about mutation rates, the notion of extrapolating from an human (or even mammalian) characteristic to the whole of the biosphere (past and present) is ludicrous enough that it would by itself cast doubt on the credibility of the author.

I don't think this is very important. Behe uses a mutation rate of 10^-8 per generation and that's pretty accurate for mammals. A better mutation rate would be 10^-10 nucleotides per DNA replication (cell generation) [Mutation Rates]. Yes, it's true that different species have different numbers of cell divisions per generation, so Behe should have mentioned this. Bacteria, for example, have a mutation rate of 10^-10 per generation because there's only one cell division per generation. (In mammals there are about 100 cell divisions, hence the mutation rate per generation is 100 times greater.)

Stephen argues that mutation rates vary from species to species and over time. I don't think so. I think the rate 10^-10 per nucleotide per replication has probably been pretty constant over several billion years and I doubt that it differs very much in different species. It's a property of the DNA replication machinery and that's always been the main source of mutation over the long term.

III. Behe claims that huge population sizes automatically generate more evolutionary opportunity than smaller ones do. This is incorrect.

It seems so obvious. More organisms means more mutations means more beneficial mutations means more and faster evolution. It's the kind of obvious, simplistic, intuitive claim that forms the bedrock of any folk science. But it's wrong.

On the contrary, very large population sizes lead to a so-called "speed limit" on adaptation that results from competition among beneficial mutations. The phenomenon is called clonal interference and it's particularly well understood in asexual organisms such as bacteria. The basic idea has been around for decades, but measurement and modeling of the phenomenon has been increasing in the last ten years. A very recent report, the subject of an upcoming post here, showed that the beneficial mutation rate in bacteria is 1000 times higher than previously thought – and the underestimation is due entirely to clonal interference.

The effect is not limited to asexual organisms; in fact, the problem of clonal interference is thought to constitute one of the major driving forces behind the evolutionary development and maintenance of sexual reproduction. The idea is that the genetic shuffling that accompanies sexual reproduction can bring beneficial mutations together and increase the effectiveness of selection.

I thought Behe was right about this. There are more mutations, and more variation, in large populations than in small ones. I thought that one of the flaws in Behe's argument is that he doesn't take into account the existence of abundant neutral and nearly-neutral alleles in a large population. Many of these contribute to the double mutations that he requires.

I'm not familiar with this idea of "clonal interference" that seems to increase the number of beneficial mutations and explains the evolution of sex. It sounds fishy to me but I'll have to read up on it—whenever I find the time. Stephen provides the appropriate references.

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Chautauqua Buskers

 

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Darwin vs. Newton

 
I claimed that Charles Darwin is the greatest scientist who ever lived. slc posted a comment on Carl Zimmer at Chautauqua.

According to Neil Tyson, Issac Newton was the greatest scientist who ever lived. Dr. Tyson, who is about the size of an NFL linebacker, is not a man I would care to have a disagreement with.

I don't want to engage in a wrestling match with Neil DeGrasse Tyson. Surely we can settle this issue peacibly?

DeGrasse Tyson is an astronomer. What would you expect him to say? Astronomers and physicists don't understand biology and they don't understand that biology is much harder than physics. Darwin is the better scientist because his subject was much harder.

Let me give you an example. Back in 1687 people didn't know very much so it was pretty easy to come up with some simple laws. Gravity was kinda obvious, don't you think? Getting hit on the head by an apple doesn't compare with collecting data by traveling about the world for five years on a small boat.

How many different laws can there be? We know that f (force) has to equal something. Does it equal m²b? Nope, that doesn't work. How about a-m. Nope. Let's try m/a ... the experiments rule that out as well. Hmmm ... maybe it's f = ma? Viola! Newton just discovered the second law of motion. Now let's invent calculus to make life miserable for undergraduates.

What about those nasty little exceptions where the planets don't seem to obey the laws? No problem, God did it.

Newton didn't even write in English! This is DeGrasse Tyson's example of the greatest scientist who ever lived?

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[Image Comment: The woman in the photograph is the only living descendant of Jesus. How appropriate that she's almost standing on the tomb of Charles Darwin!]

Nobel Laureate: Rosalyn Yalow

 

The Nobel Prize in Physiology or Medicine 1977.

"for the development of radioimmunoassays of peptide hormones"

Rosalyn Yalow (1921 - ) received the Nobel Prize in Physiology or Medicine for developing an assay to detect small quantities of peptide hormones. Her coworker and collaborator, Solomon Berson, died before the prize was awarded; otherwise he would have been included.

Yalow shared the Nobel Prize with Roger Guillemin and Andrew V. Schally.

The presentation speech was delivered in Swedish by Professor Rolf Luft of the Karolinska Medico-Chirurgical Institute.

THEME:
Nobel Laureates

Your Majesties, Your Royal Highnesses, Ladies and Gentlemen,

The word "hormones" and associated terms have always stimulated our fantasy. The mystery in connection with hormones has been, from the beginning, equally overwhelming to the researcher and the layman. It is easy to understand why. These were chemical substances with often very powerful actions at concentrations which for a long time seemed so low that they were impossible to measure. However, mystery and belief lead nowhere, at least not in scientific research and medicine. Once one learned to identify the active chemical substances - in this case hormones - and to measure their rate of synthesis, only then did one establish a firm basis for turning fantasy and mystery into reality.

This year's three Nobel laureates in medicine have all made contributions which are outstanding examples of this kind of activity. Rosalyn Yalow's name is for ever associated with her methodology of measuring the presence of hormones in the blood at concentrations as low as one thousand billionths of a gram per milliliter of blood. This was a necessity, since a great many hormones, primarily the so-called protein hormones, are present in the blood in such small quantities. Before Yalow, these hormones could not be determined quantitatively in the blood, and therefore, active research in this field had stagnated.

Rosalyn Yalow and Solomon Berson, her late coworker, discovered by chance that one small protein hormone, insulin, following injection into man resulted in a production of antibodies against insulin. All diabetics who receive insulin develop similar antibodies against the administered insulin. The discovery by Yalow and Berson was unacceptable at first - their first scientific paper concerning this observation was even refused publication - since it was commonly believed that proteins as small as these protein hormones were unable to stimulate antibody formation. However, Yalow and Berson did not give up, and furthermore, after a couple of years of intensive work, they presented in 1960 a methodology for the determination of protein hormones in the blood, the fundamental principle of which utilized the ability of these hormones to stimulate antibody formation in man. This methodology, known as the Yalow-Berson method, is genial in all its simplicity, and can even be described in simple terms.

As a result of mixing in a test tube a known quantity of radioactive insulin with a known quantity of antibodies against insulin, a specific amount of the insulin becomes attached to these antibodies. Subsequently, if one adds to this mixture a small amount of blood which contains insulin, the insulin of the blood becomes similarly attached to the antibodies and a certain portion of the radioactive insulin is detached from the antibodies. The higher the concentration of insulin is in the blood sample, the larger is the amount of radioactive insulin that will be detached from the antibodies. The amount of radioactive insulin thus removed can easily be determined, providing an exact measure of the amount of insulin present in the blood sample.

The Yalow-Berson method which makes it possible to determine the exact amounts of all hormones present, represented a real revolution in the field of hormone research. A field where one refers to the time period before Yalow, and the new epoch which began with her achievement. Her methodology and the modifications thereof, subsequently made their triumphant journey far beyond her own field of research, reaching into vast territories of biology and medicine. It has been said that Yalow changed the life of a multitude of researchers within these fields. Rarely have so many had so few to thank for so much.

Roger Guillemin and Andrew Schally have also contributed greatly to this field of research, exploring protein hormones. It is justifiable to say that they have uncovered a substantial part of the link between body and soul.

For decades, one has talked about the indivisible homo sapiens, maintaining that our body and soul can not be separated since they form an entity. Emotional and psychic phenomena do influence our bodily functions. Let me give you an example. When American soldiers were sent to the European war scene, thousands of female companions who were left behind, stopped menstruation. They were completely healthy, but the emotional stress had an influence on certain body functions, causing these functions to cease. Through which mechanisms did the psyche thus influence the body?

Psychic phenomena as well as input from the entire body bring about electrical impulses in the brain. This is the language of the nervous system, the brain speaks "electrically". The brain informs some of its centers of what is going on, and these centers relay the message further. Those centers which pass on the information to the hormone producing organs of the body are situated in the midbrain, an area on the base of the brain. Delicate blood vessels in turn connect the midbrain with the pituitary, an important hormone producing gland, often referred to as the hypophysis. This sequence provides the pathway for transmission of information from the surroundings to the brain, to the midbrain, to the pituitary, and thus to all those bodily functions which are influenced and controlled by hormones.

By the mid 1950's it was evident - also here through the contributions of Guillemin and Schally - that the midbrain produces chemical substances which are transported to the pituitary via the delicate blood vessels just mentioned. Once in the pituitary, they determine the exact quantities of the various hypophyseal hormones which must be produced at a given point in time. But which were these substances in the midbrain, evidently passing the information from soul to body?

Guillemin and Schally worked independently in different parts of the U.S.A. together with their large staff of coworkers, trying to isolate one of these chemical substances, and both researchers concentrated on the same substance. Each started with five million pieces taken from the midbrain of sheeps and pigs - half a ton - and in 1969, after years of arduous labor, they each came up with 1 milligram of the purified hormonal substance. Rarely have so many gained so little from so much.

Guillemin and Schally were the first to isolate several of the communicating chemical links between the brain and the pituitary, and they also determined their structure and succeeded in synthesizing them.

The discoveries by Guillemin and Schally brought on a revolution in their own field of research. Still other protein hormones have subsequently been isolated from the midbrain, this wondrous organ of control and guidance which today - more than ever - emerges as part of the link between the body (soma) and the soul (brain).

Rosalyn Yalow, Roger Guillemin, Andrew Schally: the road of every scientist is paved by frustration. But some reach the goal they have set up and enjoy the pleasure and excitement of having learned something that no one knew before, and for that enjoy imperishable honor in the learned world.

Few ever reach the point at which you have arrived: to undertake a formidable task and to come to a solution, which not only attracts the admiration of your scientific colleagues, but which - in the best spirit of Alfred Nobel - also contains a possibility to understand the structure of human life and human behaviour.

The Karolinska Institute is happy to be able to award you this year's Nobel Prize in Physiology or Medicine for your contributions and congratulates you. May I now ask you to receive the insignia of the Nobel Prize from His Majesty, the King.

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The Olympics Is Over: Who Won?

 
I haven't been following all that closely so I appreciate the effort made by John Wilkins to summarize the data. I hope he doesn't mind that I stole his graph from The real Olympic performers. All we have to do now is integrate the medals from the summer and winter olympic games to see the overall winners.

Congratulations to Jamaica for a well-deserved victory in Beijing.

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There Was no Timmy's at Chautauqua

 
There was no Tim Horton's at Chautauqua. The local coffee kiosk served coffee made by someone called Starbuck—or something similar. Every time I visit America I have to re-learn the language. I think I've almost got it. "Tall" means small. "Grande" means regular. And I've already forgotten what "vente" means.

I was so glad to get back to civilization yesterday and get a decent coffee in an extra large cup. (And a Boston creme donut.)

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Carl Zimmer at Chautauqua

 
Carl Zimmer gave a talk in the Hall of Philosophy on Tuesday afternoon. The photo isn't very good because I forgot my camera and had to use my cell phone.

Carl posted his talk on The Loom [Darwin, Linnaeus, and One Sleepy Guy]. He said many important things about Darwin and evolutionary biology. As a matter of fact, of all the speakers who talked about evolutionary biology, Carl was one of only two speakers who got the basics correct.¹

Here's what he said in the first minute ...

We are now descending into a frenzy of Darwin celebrations, and you’re not going to escape it until the end of 2009. We’ve got his 200th birthday in February, and the 150th anniversary of the publication of the Origin of Species in November. The spotlight is going to be on Darwin, and Darwin alone.

I think this is a mistake. Darwin deserves celebrating, but that doesn’t mean we should fall prey to a cult of personality. Darwin did not invent biology. Darwin did not even find most of the evidence that he used to back up his theory of evolution. And he certainly did not discover all there was to know about evolution. Biologists have discovered many new things about evolution since his time. In some cases, they’ve challenged some of his most important arguments. And that’s fine. That’s the great strength of science.

This reflects one of the main themes in the two courses that I taught at Chautauqua; namely, that Darwin was the greatest scientist who ever lived but we have moved far beyond what Darwin knew in 1859.

The other important point is that we risk over-emphasizing Darwin during the celebrations next year. According to Stephen Jay Gould, this is what happened in 1959 during the 100th anniversary celebrations. The result was a hardening of the Modern Synthesis and the rise of adaptationism.² I'm so glad Carl made this point. I think we all have to be careful judging by what I saw during the rest of the week and what I witnessed at a celebration of Darwin here in Toronto [Darwinism at the ROM]. Please, let's try and keep things in perspective. Whenever we praise Darwin we should also mention that modern evolutionary biology has incorporated his important contributions but added much more.

Later that night I met Carl for a few beers (three for me and decaf coffee wine for him). We had a wonderful three hours discussing evolution with Beth Shapiro and her husband—an informed engineer! Turns out, Carl is not quite as nice as he appears on his blog. In person, he actually has firm opinions about some of things he avoids discussing on The Loom.

Please don't tell him I said that. And whatever you do, don't tell him that I actually agree with some of the things he said.

We also talked about writing trade books. He convinced me that I should give it a try even though it's not nearly as rewarding³ as writing a textbook.

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1. The other one was Genie Scott.

2. The original Modern Synthesis of the 1940's was pluralistic.

3. Financially.

Beth Shapiro at Chautauqua

 
Beth Spiro is a Professor at Pennsylvania State University: Her field of expertise is the study of ancient DNA (fossil DNA) in order to learn how organisms, and species, responded to changes in the environment [Molecular Evolution]. She told us about her field work in Siberia and how she collects material from fossilized wooley mammoths and other species that lived there before, during, and after the last ice age.

Beth is an entertaining lecturer. She's a little bundle of energy on the stage, wandering back and forth sharing her obvious joy in doing science (except for the mosquitoes). Although she is best known for How to Make a Dodo, on Tuesday morning she described ways in which she might bring a wooley mammoth back to life. The experiment was illustrated with 56(?) colored ribbons representing the wooley mammoth chromosomes. Many members of the audience got to hold a "mammoth chromosome." As it turns out, the experiment might be possible but it won't be easy.

Beth Shapiro is as bright and interesting in real life as she is on the stage. That evening I met Beth and her husband when Carl Zimmer brought her along for drinks after dinner. (She drinks beer. Carl doesn't.) It was a delightful evening. I'm so happy to have met her. I was even happier to learn that she actually reads blogs!

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A Blog for Secular Students

 
Check out Edger, a Center for Inquiry student initiative.

About

Edger presents hard-hitting and reasoned news, views, and event promotion on issues pertaining to secularism, atheism, science, humanism, and the cosmos, and actively promotes and celebrates international freethought activism. Written in a youthful tone, but mature in content, Edger is sure to be a driving force in the new intellectual enlightenment.

Mission

To create an outlet for prominent young freethought leaders to express their views and get them heard. Blogs are becoming very commonplace, and alone many blogs fail, but together, with the proper direction and an engaging and professional site, these blogging leaders can come together to make an impact far beyond what they could have achieved on their own.

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