Many zoo and museum exhibits go out of their way to avoid using the word "evolved" in the text describing the exhibits. Commonly used terms are "developed", "acquired" and "emerged". The text in the photo above mentions "one theory". I wonder what that theory might be? I guess they don't want to offend their more sensitive visitors.
I like this idea: If you take your class on field trips to these places, design an exercise that charges your students with designing more interesting, evolution-based plaques. If you have a digital camera, you can take pictures of the existing plaques for use back in the classroom. Then get your students to send the ideas (slickly packaged) to the director of the place you visited. The students will enjoy being simultaneously engaged in both science and social change. There is a lot of great stuff in Purrington's evolution outreach pages.
Today I went to a lecture by Lori Lipman Brown at the New York City Skeptics. Brown, a former state senator from Nevada, is director of the Secular Coalition For America and the first Congressional lobbyist expressly representing nontheistic Americans. In her lecture, Brown detailed her lobbying efforts on behalf of nontheists and emphasized the overlap between Secularists and Skeptics.
One of the more interesting facts that came up was that the Secular Coalition For America has asked 60 congressmen what their religious views were (it was a decidedly biased sample, i.e. they did not ask Senator Brownback). Of these senators and representatives, 21 professed to be nontheists, but requested that they not be named since on account that they feared they would not be reelected. To date, only one congressman has had the fortitude to stand up and state his true beliefs: Rep. Pete Stark of California.
Another highlight was buying (yet) another Darwin/Evolution t-shirt. Afterwards, I headed downtown to the South Street Sea Port to check out Bodies: the Exhibition. The exhibit was fascinating (albeit a little creepy because all the cadavers were Chinese).
There is actually this disclaimer:
This exhibit displays human remains of Chinese citizens or residents which were originally received by the Chinese Bureau of Police. The Chinese Bureau of Police may receive bodies from Chinese prisons. Premier cannot independently verify that the human remains you are viewing are not those of persons who were incarcerated in Chinese prisons. This exhibit displays full body cadavers as well as human body parts, organs, fetuses and embryos that come from cadavers of Chinese citizens or residents. With respect to the human parts, organs, fetuses and embryos you are viewing, Premier relies solely on the representations of its Chinese partners and cannot independently verify that they do not belong to persons executed while incarcerated in Chinese prisons.
Nonetheless the exhibit was well done. Having butchered numerous amphibians in high school anatomy, I cannot imagine the effort it must have required to dissect these cadavers so exquisitely. Especially interesting was the blood vessel exhibit. Here a preservative was pumped into the vessels, and everything else was dissolved with a corrosive leaving jus the vessels. Kidneys and other important organs were amazingly dense nets of vessels. The exhibit is a little pricey (~$30), but hey you would spend that in one hour in any NYC bar.
My favorite blog is Small Things Considered. This week Elio provides an annotated list of past mini-essays for your reading convenience. Do your brain a favor and check it out!
I freely confess 99% of what I read these days is non-fiction, but in my (misbegotten) youth I frequently dabbled in the *gasp* humanities.
The rules: boldface the books on this list that you've read, and italicize books you started but never finished.
1 Pride and Prejudice - Jane Austen 2 The Lord of the Rings - JRR Tolkien(the trilogy actually) 3 Jane Eyre - Charlotte Bronte 4 Harry Potter series - JK Rowling(ugh) 5 To Kill a Mockingbird - Harper Lee 6 The Bible 7 Wuthering Heights - Emily Bronte 8 Nineteen Eighty Four - George Orwell 9 His Dark Materials - Philip Pullman 10 Great Expectations - Charles Dickens 11 Little Women - Louisa M Alcott 12 Tess of the D'Urbervilles - Thomas Hardy 13 Catch 22 - Joseph Heller(Hilarious) 14 Complete Works of Shakespeare 15 Rebecca - Daphne Du Maurier 16 The Hobbit - JRR Tolkien 17 Birdsong - Sebastian Faulks 18 Catcher in the Rye - JD Salinger 19 The Time Traveller's Wife - Audrey Niffenegger 20 Middlemarch - George Eliot 21 Gone With The Wind - Margaret Mitchell(Does the movie count?) 22 The Great Gatsby - F Scott Fitzgerald 23 Bleak House - Charles Dickens 24 War and Peace - Leo Tolstoy 25 The Hitch Hiker's Guide to the Galaxy - Douglas Adams(So long Doug and thanks for all the erm... books) 26 Brideshead Revisited - Evelyn Waugh 27 Crime and Punishment - Fyodor Dostoyevsky(Brothers Karamazov was better IMHO) 28 Grapes of Wrath - John Steinbeck 29 Alice in Wonderland - Lewis Carroll 30 The Wind in the Willows - Kenneth Grahame 31 Anna Karenina - Leo Tolstoy 32 David Copperfield - Charles Dickens 33 Chronicles of Narnia - CS Lewis 34 Emma - Jane Austen 35 Persuasion - Jane Austen 36 The Lion, The Witch and The Wardrobe - CS Lewis 37 The Kite Runner - Khaled Hosseini 38 Captain Corelli's Mandolin - Louis De Bernieres 39 Memoirs of a Geisha - Arthur Golden 40 Winnie the Pooh - AA Milne 41 Animal Farm - George Orwell 42 The Da Vinci Code - Dan Brown (regrettably) 43 One Hundred Years of Solitude - Gabriel Garcia Marquez 44 A Prayer for Owen Meany - John Irving 45 The Woman in White - Wilkie Collins 46 Anne of Green Gables - LM Montgomery 47 Far From The Madding Crowd - Thomas Hardy 48 The Handmaid's Tale - Margaret Atwood 49 Lord of the Flies - William Golding 50 Atonement - Ian McEwan 51 Life of Pi - Yann Martel 52 Dune - Frank Herbert(this might be a rare instance of the movie being better) 53 Cold Comfort Farm - Stella Gibbons 54 Sense and Sensibility - Jane Austen 55 A Suitable Boy - Vikram Seth 56 The Shadow of the Wind - Carlos Ruiz Zafon 57 A Tale Of Two Cities - Charles Dickens 58 Brave New World - Aldous Huxley 59 The Curious Incident of the Dog in the Night-time - Mark Haddon 60 Love In The Time Of Cholera - Gabriel Garcia Marquez 61 Of Mice and Men - John Steinbeck 62 Lolita - Vladimir Nabokov 63 The Secret History - Donna Tartt 64 The Lovely Bones - Alice Sebold 65 Count of Monte Cristo - Alexandre Dumas 66 On The Road - Jack Kerouac 67 Jude the Obscure - Thomas Hardy 68 Bridget Jones's Diary - Helen Fielding(This was a snap buy in an airport bookstore for a flight I was almost late for. I should have gone with David Sedaris) 69 Midnight's Children - Salman Rushdie 70 Moby Dick - Herman Melville(for a long time this was my favorite book) 71 Oliver Twist - Charles Dickens 72 Dracula - Bram Stoker 73 The Secret Garden - Frances Hodgson Burnett 74 Notes From A Small Island - Bill Bryson(I'm still pissed about A Walk In the Woods. You'd think someone who writes about hiking the Appalachian Trail would have actually hiked it) 75 Ulysses - James Joyce(has anyone ever finished?) 76 The Bell Jar - Sylvia Plath 77 Swallows and Amazons - Arthur Ransome 78 Germinal - Emile Zola 79 Vanity Fair - William Makepeace Thackeray 80 Possession - AS Byatt 81 A Christmas Carol - Charles Dickens 82 Cloud Atlas - David Mitchell 83 The Color Purple - Alice Walker 84 The Remains of the Day - Kazuo Ishiguro 85 Madame Bovary - Gustave Flaubert 86 A Fine Balance - Rohinton Mistry 87 Charlotte's Web - EB White 88 The Five People You Meet In Heaven - Mitch Albom 89 Adventures of Sherlock Holmes - Sir Arthur Conan Doyle 90 The Faraway Tree Collection 91 Heart of Darkness - Joseph Conrad 92 The Little Prince - Antoine De Saint-Exupery(I think I have read everything by Saint-Exupery I could get my hands on) 93 The Wasp Factory - Iain Banks 94 Watership Down - Richard Adams 95 A Confederacy of Dunces - John Kennedy Toole 96 A Town Like Alice - Nevil Shute 97 The Three Musketeers - Alexandre Dumas 98 Hamlet - William Shakespeare 99 Charlie and the Chocolate Factory - Roald Dahl(James and the Giant Peach was better) 100 Les Miserables - Victor Hugo
This week's citation classic comes from Dan Simberloff and Ed Wilson, and in terms of scale, ranks of one of the most daunting ecological experiments every attempted. The pair was interested in the recolonization process following an extinction event. Specifically they wanted to test whether the number of species on an island existed in a dynamic equilibrium with present species going extinct being replaced by new immigrants.
The classic example of a major extinction event was the eruption of Krakatoa. When Krakatoa exploded in 1883, it exterminated every living organism on the island. When the first researchers reached the islands in May 1884, the only living thing they found was a spider in a crevice on the south side. However life quickly recolonized the island and today it supports a large ecosystem.
Krakatoa was a natural experiment. The question was, how to replicate Krakatoa on a controlled basis. Simberloff and Wilson hit upon the idea of fumigating entire mangrove islands by encasing the islands in a canopy of plastic sheeting and pumping in methyl bromide (which killed the bugs, but not the mangroves). Prior to and after fumigation, every single arthopod on the island was collected and identified. It was, needless to say, a massive endeavor.
Simberloff comments, "Even identifying the over 100 species that we found required us to enlist an army of systematists, and physical aspects of operating in the shallow, shark-infested waters of the Florida Keys put us one up on molecular biologists who always seemed engaged in momentous breakthroughs."
But it worked!
Simberloff and Wilson found that following defaunation, the number of species on islands recovered previous levels. What's more is that they showed substantial species composition changes over time indicating extinction and immigration. In terms of sheer boldness, this is one of my favorite experiments. It's hard to imagine an established scientist attempting something of this magnitude with just a graduate student. But Ed Wilson was always a bold visionary.
Will our future Nobelists get their first taste of science from video games? The Nobel Prize organisation hopes so. They have available a series of educational games based on previous Nobel Prizes. My first run of malaria I was quickly killed by DDT =/ Then I thought (incorrectly) that I could obtain blood from a bird. I was quickly consumed. Then once I found a host, I took too long to draw blood and was swatted. It's hard out there for a mosquito!
This week's citation classic comes from Nobelists Salva Luria and Max Delbruck and is one of the most famous experiments in biology. Luria and Delbruck wondered about the nature of mutations. Are mutations spontaneous? Or do they occur in response to environmental conditions? The latter view, common to scientists of the day (e.g. Cyril Hinshelwood), was one of the last vestiges of Lamarckism in evolutionary biology.
Since the time of d'Herelle, it was known that a culture of bacteria exposed to bacteriophage would eventually become clear, as if all the bacteria in the culture were killed. However, eventually the culture would grow cloudy again. It was surmised that the bacteria acquired resistance to the phage, and were able to repopulate the culture. The question was, how can the system be used to demostrate the role of chance in mutations?
Luria struggled with the problem for several months, trying to devise a test to show that mutations were spontaneous. Then at a faculty dance at Indiana University, Luria had his eureka moment.
"During a pause in the music I found myself standing near a slot machine, watching a colleague putting dimes into it. Though losing most of the time he occasionally got a return. Not a gambler myself, I was teasing him about his inevitable losses, when he suddenly hit a jackpot... gave me a dirty look at walked away. Right then I began giving some thought to the actual numerology of slot machines; in doing so, it dawned on me that slot machines and bacterial mutations have something to teach each other." (From Luria's autobiography: A Slot Machine, A Broken Test Tube).
Luria returned to the lab and set up a large number of bacterial cultures containing just a small number of bacteria in each, to which he added some bacteriophage. Luria reasoned that if mutations were spontaneous, then their distribution would resemble jackpots. Here the number of surviving bacteria would be small in most cultures, but large in a handful. On the other hand, if mutations were directed as the Lamarckists supposed, then their payoffs would be evenly distributed. Each culture would contain a small number of mutants, as the figure here shows:
Luria and Delbruck's experiments showed unequivocally that mutations were spontaneous and emphasized the role of chance and historicity in evolutionary biology, thus putting the final nail in the coffin of Lamarckism. See Fig. 2 from L&D's paper where the number of jackpots (>9 resistant bacteria) far exceeds that expected by chance. The reason I selected the Fluctuation Test as this week's citation classic is because of a recent exchange between Rich Lenski and I, of which I reprint portions of here:
"I've always been fascinated by the tension between chance and necessity, between randomness and repeatability. As a kid, for example, I especially liked games with dice and cards that involved both luck and skill.
Then, when I was at Oberlin College, I took a wonderful course in which we used Gunther Stent's "Molecular Genetics: an Introductory Narrative" as a text. Unlike most science textbooks, it emphasized the history of who did what experiments and why. I remember reading about the "fluctuation test" performed by Salvador Luria and Max Delbruck, and trying to make sense of it, and then having that eureka moment when the whole point of the experiment hit me. It's my all-time favorite experiment and to this day, whenever I think about it, I'm struck not only by its elegance, but also by the subtlety of the interpretation and by an appreciation of why the problem had been so difficult until they did their experiment.
As you know, a main focus of the long-term evolution experiment with E. coli has been to better understand the repeatability of evolution that arises from the tension between random mutation, on the one hand, and the systematic process of natural selection, on the other hand, that pushes populations toward greater fitness in the environments in which they live. So in a way, you might think of my long-term evolution experiment as a descendant of the fluctuation test, one that examines the role of random mutation in producing statistically quantifiable variation between replicate lineages, not in overnight cultures but across, now, more than 40,000 generations of evolution."
It is precisely this randomness of evolution that led to Lenski's and colleagues latest discovery that, after 33127 generations, a strain of E. coli evolved the ability to digest citrate. Carl Zimmer does a bang up job of covering that story.
Lenski also had a recent dustup with the IDiots, and his tolerant response is covered here.
Update:P Jonathan Eisen of Tree of Life also wrote about this paper here.
Photo: Max Delbruck, Salvador Luria, and Frank Exner at Cold Spring Harbor Laboratory from the National Library of Medicine.
I'm an evolutionary biologist who studies bacteriophage life history stochasticity and the population dynamics of host/pathogen interactions I'm currently affiliated with Queens College and the CUNY Graduate Center. I can be reached at john.dennehyATqc.cuny.edu
Many zoo and museum exhibits go out of their way to avoid using the word "evolved" in the text describing the exhibits. Commonly used terms are "developed", "acquired" and "emerged". The text in the photo above mentions "one theory". I wonder what that theory might be? I guess they don't want to offend their more sensitive visitors.
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