Aristotelian dental logic
Every introductory class in biological anthropology talks about wisdom teeth, the common name for human third molars. Around ninety percent of my students in any given semester have had these pulled, or never got them at all. Problems with the eruption or alignment of the third molars are very common, causing pain or infection. Even in cases where the teeth might ultimately not pose a long-term problem, many dentists pull them as a prophylactic. Natural cases of non-eruption are fairly common also. Sometimes these are nevertheless present, and may be removed surgically. Other times, the third molars never formed at all. As a result of both natural variation and orthodontic practice, it is increasingly rare for adults to have wisdom teeth.
Since this natural variation is so well-known to anthropologists, I was intrigued to find in a comment to a post at Gene Expression that Aristotle believed men had more teeth than women. I went in search of the essential citation, and found it in "The History of Animals," book 2, part 1 (translated by D'Arcy Wentworth Thompson):
Males have more teeth than females in the case of men, sheep, goats, and swine; in the case of other animals observations have not yet been made: but the more teeth they have the more long-lived are they, as a rule, while those are short-lived in proportion that have teeth fewer in number and thinly set.
Part 4
The last teeth to come in man are molars called 'wisdom-teeth', which come at the age of twenty years, in the case of both sexes. Cases have been known in women upwards. of eighty years old where at the very close of life the wisdom-teeth have come up, causing great pain in their coming; and cases have been known of the like phenomenon in men too. This happens, when it does happen, in the case of people where the wisdom-teeth have not come up in early years.
There may be no accounting for Aristotle's claim that men have more teeth than women, since on average they are the same. On the other hand, with the variation in third molar eruption it is quite possible that the women available for Aristotle to examine might have -- by chance -- had fewer teeth. The idea that there is a systematic difference between men and women would appear to be belied by the following section, where Aristotle clearly discusses the presence of the wisdom teeth in both sexes. This part is a vivid illustration of the problems of the posterior dentition in general -- ancient Greeks and modern Americans alike.
I was similarly fascinated to see that "wisdom teeth" was a translation from the ancient Greek. Here's the entry from the Online Etymology Dictionary:
Wisdom teeth so called from 1848 (earlier teeth of wisdom, 1668), a loan-translation of L. dentes sapientiae, itself a loan-transl. of Gk. sophronisteres (used by Hippocrates, from sophron "prudent, self-controlled"), so called because they usually appear ages 17-25, when a person reaches adulthood.
Here I thought it was just one of those old sayings nobody could account for. And did you know that "catty-corner" comes all the way from Middle English?
Soccer coach, yes; birth coach, not so much
A Slate column by Meghan O'Roarke discusses the latest trend in male vilification:
A man who doesn't want to watch his wife give birth is a jerk. This was the overwhelming consensus reached by a host of respected blogs after the publication last Tuesday in the New York Times of a piece [don't bother unless you're a subscriber] by a therapist noting an unhappy trend: A number of his male patients have reported that after witnessing their wives have babies they no longer feel attracted to them. "I mean, how are you supposed to go from seeing that to wanting to be with ...?" one husband asked, unable to finish his sentence. It made no difference that these men were patients in search of help, not Neanderthals who'd ditched their wives; the bloggers--many of whom are usually temperate--were outraged. "Would it hurt if I call you a big pussy?" one woman queried, adding, "Luckily for me, I didn't marry a total asshole, so I didn't have this problem." According to one post, a husband who finds his libido gone in the wake of the delivery room merits the same scorn we'd direct at a man who leaves a woman after finding out that she has a black grandparent.
Happily, this is not a problem I have had. After four kids, I have to say that birth has no power to gross me out. And man, would I have been a heel if I missed any of them!
But it's not really about birth, now is it? The premise of half the reality shows on TV is that there are some unusual things (eating worms, letting rats crawl on your face, rappelling face-first down a building) that some people will do and others will be totally creeped out by. Most of these are more scary than watching a birth, but should we really be surprised that some men might prefer to take in 18 holes rather than have umbilical blood spurt onto their noses?
It's a new masculine challenge -- heck, fifty years ago men were virtually absent at the birth of their own children. And that's the bottom line of the new stories about it:
But what was nonetheless striking about the debate was the vehemence of the hostility directed at these men. The bloggers clearly felt that the men's desire (or lack of it) was objectively wrong, like that of a pedophile or a rapist, and ought somehow to be controllable. The animus against these men illuminates how powerful even relatively new cultural norms can be--and how dramatic the conflict is between what we think people should want and what they actually do want.
A new cultural norm, at least for some parts of the country. I watched the movie Nine Months a few weeks ago. When that movie came out in 1995, most people probably thought Hugh Grant's revulsion to all things pregnanthetic was light comedy. I have to say, upon seeing it again now, I just thought he was an ass. Now, there must have been a lot of people then that felt that way (rather than that he was just a terminally clueless man-boy), but the reaction to the movie now must be much more negative.
Tracking down quotes like this one epitomizes why Meghan O'Roarke is my favorite Slate writer:
The idea that childbirth was natural and therefore beautiful wasn't actually embraced by all feminists. Shulamith Firestone insisted that modern feminism shouldn't celebrate childbirth, but hope that science could soon render women's role in it obsolete. She writes, "Pregnancy is barbaric. ... The husband's guilty waning of sexual desire, the woman's tears in front of the mirror at eight months are all gut reactions, not to be dismissed as cultural habits. ... Three thousand years ago women giving birth 'naturally' had no need to pretend that pregnancy was a real trip, some mystical orgasm."
Personally, I think we should find it amazing that men have made this radical change as painlessly as they have. The kind of direct participation that is possible now for fathers is unusual in a historical and cross-cultural perspective. Yet, most fathers have leapt at the chance to be more involved.
Royal pains, circa 1550
Here's some good news in medicine:
A 450-year-old piece of Charles V's pinkie lends support to the theory that it was gout that led one of the most powerful rulers of all time to abdicate, Spanish researchers report.
Thus solving a complete medical mystery!
Er...
Holy Roman Emperor Charles V, whose empire stretched across Europe and included Spanish America, was diagnosed with gout by his doctors in early adulthood.
Oh well, hopefully with this research, no monarch will ever again have to abdicate because of gout.
Er...
Gout has long been associated with rich diets and alcohol. According to the researchers, Charles V had a big appetite, especially for meat, and drank large amounts of beer and wine.
Stop, Prince William, before it's too late!
Columbus DNA informatics
An article in the Washington Post by Guy Gugliotta discusses the identity of Christopher Columbus, on the 500th anniversary of his death.
To commemorate this event, researchers led by Spanish forensic pathologist José Antonio Lorente Acosta are comparing the DNA of Columbus's illegitimate son, Fernando, with DNA from hundreds of possible Columbus descendants in at least three countries.
The goal is to determine once and for all whether Columbus, as traditionalists hold, was the son of Genoese wool weaver Domenico Colombo, or was instead a Spaniard named Colon; or a Catalan Colom, from Barcelona; or a French Coulom or Colomb; or perhaps Corsican or Mallorcan.
This is all building up suspense for a release of the findings on Saturday.
They wanted to sample DNA from the bones at two different gravesites attributed to Columbus, one in Seville and one in the Dominican Republic. But it didn't work out:
The plan foundered because there were not enough remains from Seville to provide conclusive DNA samples, and the Dominican government refused to let the team examine the bones there, telling Lorente he had been authorized only to evaluate the "state of preservation of the admiral's remains," not take samples.
Good for them, I say! Maybe they heard about the Mozart fiasco.
I quite like the informatic approach they have ended up -- it seems like sampling everybody in Europe they could find with a name like "Columbus." Even so, it has a good chance of not working, so there is some suspense.
There's a lot more in the article about the textual evidence for Columbus' origins and the reasons for him to have been secretive about it.
King Kong humanzee trivia
I'm coming late to this story, but it's still timely! The New York Times has an op-ed by Clive Wynne linking the inspiration for the original King Kong to Soviet attempts to breed a chimpanzee-human hybrid:
The young Soviet Union, in its effort to stamp out religion, was determined to prove that men were descended from apes. In 1926, a Soviet scientist named Ilya Ivanov decided the most compelling way to do this would be to breed a humanzee: a human-chimpanzee hybrid.
Ivanov set off for a French research station in West Africa. There he inseminated three female chimpanzees with human sperm. Not his own, for he shared the colonial-era belief that the local people were more closely related to apes than he was. He stayed long enough to learn that his experiment had failed.
Next Ivanov wrote a Cuban heiress, Rosalia Abreu. Abreu was the first person to breed chimps in captivity and had a large menagerie outside Havana. Ivanov asked if any of her male chimpanzees might be available to inseminate a Russian volunteer known to posterity only as 'G."
The link to King Kong is not all that convincing, but the story of how this Soviet science project was ultimately stalled by the Ku Klux Klan is a good read.
I found the story via Evolgen, which has further thoughts about human-chimpanzee hybridization and chromosome number incompatibility. Evolgen got the story from John Wilkins' Evolving Thoughts, which has further thoughts as concerns hybridization in the development of nineteenth-century biology. All well worth a read, especially since they are free supplements to the movie!
Now, if someone could explain to me why there is a single giant gorilla on this island of dinosaurs?
Or better, why the gorilla isn't a dwarf? I can understand about the dinosaurs -- after all, reptiles get bigger on islands, right?
And that's why CSI is fiction
From the AP story "Mozart mystery just gets murkier":
After months of sophisticated DNA sleuthing reminiscent of a "CSI: Crime Scene Investigation" episode, forensics experts admitted Sunday on national television that they still can't say with certainty whether an ancient skull belonged to the composer, as some believe.
They tried to compare the mtDNA of the skull with two maternal relatives from the "Mozart family grave" in Salzburg. But the maternal relatives didn't have the same mtDNA sequence!
Experts had assumed the remains were of Mozart's maternal grandmother and a niece. But DNA analysis showed that none of the skeletons in the grave were related, making it impossible to prove that the skull was Mozart's, Parson said.
"The dead took their secrets to the grave," the documentary concluded.
Or someone else's, evidently.
Venter's quest
On the subject of Craig Venter, I ran across this old interview from Bio-IT World magazine. It's pretty useful for a short first-hand account of his side of the genome sequencing controversies.
Here's an excerpt:
Q: You divulged earlier this year that your DNA was one of the samples used in Celera's genome assembly. Why did you reveal that? It seemed to upset a few people ...
A: It does seem to have done that. But it was actually a very complicated decision. The number one thing I hear in conversation ... is that people are afraid that their genetic code will be used against them. To me, there are two types of leadership. In Vietnam (Venter served as a Navy corpsman during the Tet offensive in 1968), there were the leaders that pushed the small guy out in front to be the point man to step on the booby traps and get shot first. And there are the leaders who actually led and got people to follow them. I've never been one to push people out in front of me to get shot first.
I was a donor out of just absolute scientific curiosity. My view is, how can anybody possibly work in this field and not want to know their genetic code? Something's wrong with them! I mean what the hell are they doing? It's the ultimate dishonesty. They're advocating other people should do this. 'We're going to interpret your life but boy, stay away from mine?' I'm not shy about that. I wanted to know my own genetic code to understand my own life. I'm writing a book about that.
Q: Did you identify genes that showed you're predisposed to certain diseases? Did you go that far?
A: Yes. In fact, some of the people at Celera have shown slides at public meetings. They were showing some of my disease genes.
A bit of counterpoint to all the people who wouldn't pay the price of a CD for their genomes. This man developed a whole science to do it.
Weismann's mosaicism
I've been reading Ron Amundson's new history of biology book, The Changing Role of the Embryo in Evolutionary Thought.
I'll be posting a lot on this book over the next couple of weeks, as I have taken a lot of notes. In short, I find it to be a very interesting and thought-provoking revision of the history of evolutionary theory. I often find when I'm reading a history that things didn't happen the way I learned in school. Amundson gives example after example of the way that the history of biology was constructed to defend a specific set of beliefs -- those that constituted the Evolutionary Synthesis. The result is that in many particulars, the history of pre-Darwinian and post-Darwinian biology that you thought you knew just isn't the way things really happened. Amundson's particular interest is development, and especially the ways that developmental biology was jettisoned along the road to neodarwinism.
On page 144, August Weismann enters the story. If you know the history of biology, then you probably remember one key fact about Weismann: he innovated the distinction between germline and somatic cells. You probably remember this because the sequestration of the germline explains why Lamarckian inheritance is impossible --- changes to the somatic cells cannot affect the germline cells that ultimately produce gametes. That's an essential insight to population genetics: it underlies particulate inheritance. It also is usually taken to mean that the transmission of genes to offspring is independent of the processes of development; in other words, it underlies the distinction between transmission genetics and developmental genetics.
You may know a lot more than this about Weismann, but I certainly didn't, so I was intrigued by the real motivation for his theory.
Weismann enters Amundson's narrative as an example of pre-synthesis models of heredity. As it turns out, under Weismann's theory, the germline sequestration was necessary not to refute Lamarckian inheritance, but to allow embryonic development itself:
The central problem of the study of embryological development is explaining the increase in heterogeneity in the developing embryo. Seen in terms of the cell theory, increased heterogeneity could be conceived as cellular differentiation. How does the single cell of the zygote give rise through division to the specialized cells of the various parts of the body? The answer given by Weismann and [Wilhelm] Roux was the mosaic theory of development. Roux stated his version of the mosaic theory in 1885, the same year that Weismann proposed the germ-soma distinction. Mosaic or autonomous theories of development assert that the nature of body parts is determined in advance of their acutal development, and determined independently of the body parts around them. In contrast, regulative theories of development claim that body parts take their nature from their position within the embryo (Amundson 2005:145, emphasis in original).
How did this "mosaic theory" work? The cytoplasm was theorized to contain particles (ultimately called determinates) that comprised all the hereditary information. As the embryo differentiated, different cells received different subsets of the original determinates. Cells that received bone-determinates became bone cells, those that received heart-determinates became cardiac cells, and so on. Therefore the original heritable material was parcelled out to different somatic cells, meaning that no somatic cell contained all the determinates necessary to construct an entire body. In this theory, heredity and ontogeny were inextricably linked: indeed, the hereditary particles were directly responsible for the development of the organism.
It is easy to see that under this theory, the sequestration of the germline is essential, otherwise reproduction would be impossible. Only by setting aside a group of cells that would retain all the hereditary determinates could the ability to produce another individual be transmitted to the next generation. Weismann's mechanism of development dictated the germ-soma distinction.
As Amundson describes, the mosaic theory fell out of favor for two reasons. Embryologists didn't like it because it didn't really explain the formation of different tissues. Although the theory was intended to explain why the differentiation occurred (through the progressive assortment of determinates into different tissues), it didn't explain how those determinates actually got into their ultimate positions or how they determined the actual properties of different tissues.
And it was found to be inconsistent with the burgeoning field of genetics, under the influence of Thomas Hart Morgan. Cells were found to divide equally in all cases, and genetic material was found to assort equally into both daughter cells. This removed any empirical support for the "determinates", and left the mosaic theory without a credible mechanism.
Amundson's point in describing the theory is to point out that before Morgan, heredity was universally assumed to involve development: individuals inherited not an information-bearing particle, like DNA, but instead the ontogenetic program. This concept of heredity could not lead to population genetics, because it did not admit a mathematical analysis of inheritance along Mendelian lines. Instead, population genetics developed upon Morgan's assertion that the tranmission of traits from parents to offspring could be studied even in the absence of knowledge of how the traits develop.
Weismann's germ-soma distinction was thus resurrected as a key to Mendelian inheritance: it explained the transmission of genetic material to offspring as independent of the process of development. Amundson cites John Maynard Smith to this effect, and adds:
In 1927, Weismann was the emblem of the integration of development and heredity; in 1982, he was the hero who had divorced the two fields. Why the change? ... Embryology itself was almost forgotten, and Weismann's mosaic embryological theory was totally forgotten. This enabled a replacement of the historical Weismann ... with the modern pseudo-Weismann (whose germ line-soma distinction seemed to anticipate the genotype-phenotype distinction. References to Weismann were absent from formative Synthesis literature. Later in the century, Weismann was recalled to mind -- he was the person who had refuted Lamarckism with his germ line-soma distinction (ibid., 219).
Weismann has gained special importance in evolutionary theory for his argument against use-inheritance for a good reason: Darwin himself embarrassingly (at least to the modern sensibility) assumed that use-inheritance was an important source of heredity. Thus, Weismann's germ-soma distinction is placed as a corrective to Darwin, and thereby a major advance toward modern evolutionary theory.
In view of Weismann's actual ideas, this posturing is highly ironic.
UPDATE: I have intended to give Gould's Structure of Evolutionary Theory another look after finishing Amundson to compare their treatment of the embryology. But upon writing this, I felt like checking what Gould had to say about Weismann. Apparently he didn't get Amundson's point at all --- perhaps the genotype-phenotype distinction was drilled into Gould once too often, also. Instead, Gould focuses on Weismann's later theory of germinal selection as a precursor to his own multilevel selection ideas. Thus he gives Weismann a good 20 pages, but doesn't outline the importance of his mechanism of heredity to the germ-soma distinction.
Audubon et al.
A book excerpt in the Telegraph by David Attenborough asks this question:
Animals were the first things that human beings drew. Not plants. Not landscapes. Not even themselves. But animals. Why? The earliest known drawings are some 30,000 years old. They survive in the depths of caves in western Europe. The fact that some people crawled for half a mile or more along underground passages through the blackness is evidence enough that the production of such pictures was an act of great importance to these artists.
He doesn't answer the question, but gives an interesting history of the tradition of animal art, from early Christian scribes drawing emblematic animals in saints' portraits to Catesby, Audubon, and John Gould.
I happened across it because of the cave art reference. Readers interested in art history and art in science will enjoy the excerpt, which is from a book accompanying an art exhibition in Edinburgh.
Looking back to the golden age
British physiologist Harry Rossiter suggests that ancient Greeks were more physically fit than modern endurance athletes:
Dr Rossiter measured the metabolic rates of modern athletes rowing a reconstruction of an Athenian trireme, a 37m long warship powered by 170 rowers seated in three tiers. Using portable metabolic analysers, he measured the energy consumption of a sample of the athletes powering the ship over a range of different speeds to estimate the efficiency of the human engine of the warship. The research is published in New Scientist.
By comparing these findings to classical texts that record details of their endurance, he realised that the rowers of ancient Athens -- around 500BC -- would had to have been highly elite athletes, even by modern day standards.
Says Dr Rossiter: "Ancient Athens had up to 200 triremes at any one time, and with 170 rowers in each ship, the rowers were clearly not a small elite. Yet this large group, it seems, would match up well with the best of modern athletes. Either ancient Athenians had a more efficient way of rowing the trireme or they would have to be an extremely fit group. Our data raise the interesting notion that these ancient athletes were genetically better adapted to endurance exercise than we are today."
Then again, Pheidippides did fall down dead after the first marathon...
(via Dienekes, who is skeptical)
Crosby on prior historians
This is a nice passage by Alfred Crosby about the work of nineteenth and early twentieth century historians:
Rather than make a display of our "superiority" over scholars now dead and buried (thus anticipating the smugness or our own successors), let us praise our forebears. They were skilled practitioners of the historian's craft who did their work well, enabling the present generation of historians to make progress, rather than mere corrections. Men like Spain's Martín Fern´ndez de Navarette and Canada's Henri-Raymond Casgrain drew together the documentary evidence that forms the core of what even revisionists must begin with, and assembled the bare date of who was who and where and when. These scholars performed the laborious work that is preliminary to creative scholarship in any field of history. Among them were creative scholars of the first rank who built a model of the past that reconciled the record as they knew it with the values of their own day and made sense to the literate classes of their time. This is what society pays historians to do (Crosby 1994:5).
That seems like such a gentlemanly way to describe those whose shoulders you stand on; even when your task is to lay bare the assumptions that misled them so greatly.
References:
Crosby AW. 1994. Germs, Seeds and Animals: Studies in Ecological History. M. E. Sharpe, Armonk, NY.
Blogging for Beagle
The Beagle Project Blog lists me as one of the top ten senders of traffic to their site, which reports on the efforts to replicate the original voyage:
We aim to celebrate Charles Darwin's 200th birthday by building a sailing replica of HMS Beagle and recreating the Voyage of the Beagle with an international crew of researchers, aspiring scientists and science communicators. The voyage will apply the techniques of 21st century science to Darwin's journey, inspiring a new generation of scientists and promoting the public understanding of evolution and wider science.
So, I thought I would post to send them a little more!
Hrvatski Origin of Species
A letter to the editors of Nature by Jasmina Muzinic notes the new translation of Darwin's works into Croatian:
Charles Darwin's On the Origin of Species and The Descent of Man have at last been translated into Croatian, thanks to the work of the renowned science and theology translator Josip Balabanic. Other European countries -- including Denmark, the Netherlands, France, Germany, Italy, Poland, Russia and Sweden -- had access to Darwin's works in their mother tongue during his lifetime. But it was not until this year that Croatian students of biology could read them in their own language.
Cool.
"Like confessing a murder"
The Darwin Correspondence Project has put the text of 5000 Darwin letters online. The NY Times has a number of excerpts. Here's a good one:
It was at the end of a letter to the botanist Joseph Dalton Hooker, Darwin's closest friend, that, building slowly, he dropped his bombshell of a notion in 1844, 15 years before "Origin":
I have been now ever since my return engaged in a very presumptuous work & which I know no one individual who wd not say a very foolish one.— I was so struck with distribution of Galapagos organisms &c &c & with the character of the American fossil mammifers, &c &c that I determined to collect blindly every sort of fact, which cd bear any way on what are species. — I have read heaps of agricultural & horticultural books, & have never ceased collecting facts — At last gleams of light have come, & I am almost convinced (quite contrary to opinion I started with) that species are not (it is like confessing a murder) immutable. Heaven forfend me from Lamarck nonsense of a "tendency to progression" "adaptations from the slow willing of animals" ... but the conclusions I am led to are not widely different from his — though the means of change are wholly so — I think I have found out (here's presumption!) the simple way by which species become exquisitely adapted to various ends.
Darwin myths exposed
Jim Endersby presents a review of two recent books on Darwin -- a Variorum edition of the Origin, and a new edition of Darwin's correspondence -- in the Times Literary Supplement.
Take, for example, the mythical clash between science and religion. The Victorian âcrisis of faithâ predated the Origin by many years; Tennyson found himself stretching âlame hands of faithâ when confronted by ânature red in tooth and clawâ in 1850, almost a decade before Darwin went public. When Nature gave voice in Tennysonâs In Memoriam, instead of demonstrating the existence and beneficence of the creator, she expressed complete indifference for species, the âtypesâ of living things: ââSo careful of the type?â but no. / From scarped cliff and quarried stone / She cries, âA thousand types are gone: / I care for nothing, all shall go'â.
It was the fossilized evidence of extinct species, entombed in the cliffs (until the quarrying, mining, railway building and canal cutting of the Industrial Revolution revealed them) that led men like Tennyson to doubt that âGod was love indeedâ. These were doubts that he, and many of his contemporaries, had harboured at least since the 1830s, when Charles Lyellâs geological theories gave them a glimpse of the terrifying vastness of time. An ancient Earth was not inherently disturbing, but the fossil record made it clear that for most of its long history, the Earth had been uninhabited by people. If, as the Bible claimed, this planet had been made as a habitation for humanity, why had its creator taken so long to get the tenants in? And if God was such a great designer, why was almost everything heâd designed now extinct?
Any review that can quote Tennyson in service of Darwin is bound to be a gem; this one surpasses by including many of the telling reactions to Darwin's work, including Dennert's famous line:
Despite the enormous historical importance of Mendelâs work, it was nineteenth-century plant-breeding, not twentieth-century genetics; a lot of hard work (and a great many fruit flies) would be needed to transform Mendelâs insights into modern genetics. As a result, the rediscovery of Mendelâs work, far from cementing Darwinâs triumph, initially led to his downfall, since many perceived the fledgling science of âMendelismâ to be a satisfactory alternative to the seemingly outdated Darwinian natural selection; in 1903, a German botanist wrote: âWe are now standing at the death bed of Darwinism, and making ready to send the friends of the patient a little money to ensure a decent burial of the remainsâ.
It sums up to a good list of various "myths" about Darwin and his work, and is a good read even if you've heard most of it before
(via henry)
Darwin at 199
This Saturday (2/8/2008) is Darwin Day here at UW. My lab will be putting a display together at the Geology Museum in the afternoon -- you can find a full schedule and flyer at the UW Darwin Day website.
The real Darwin Day is February 12 (just like Lincoln!), and he was born in 1809 (just like Lincoln!). In honor of the occasion, Nature prints an essay by Kevin Padian reviewing Darwin's scientific legacy.
In the past century and a half, Darwin's ideas have inspired powerful images and insights in science, humanities and the arts. Meanwhile, countless commentators ignorant of his meaning have borrowed his eloquence to plump their own chickens -- from capitalism to 'evolutionary psychology'. Darwin has been invoked as the demon responsible for a variety of perceived heartless ills of society, including atheism, Nazism, communism, abortion, homosexuality, stem-cell research, same-sex marriage, and the abridgement of all our natural freedoms. One can scarcely imagine the horror that Darwin would feel at the misunderstanding, misappropriation and vilification of his ideas in the 125 years since his death.
The essay is a list of "big ideas" from Darwin, along with some of their later developments. Natural selection, monogenism, genealogical classification, the action of imperceptible forces over long periods of time ("deep time"), biogeography, sexual selection, coevolutionary relationships, gradualism, and natural economy all merit entries, along with a few others.
I particularly liked this passage describing Darwin's conception of coevolution:
One of Darwin's lesser-known books is On the Various Contrivances by which British and Foreign Orchids are Fertilised by Insects and on the Good Effects of Intercrossing (1862). It encapsulates the concept that species of very different origins have evolved mutual ecological relations through time that have come to affect critical aspects of their morphologies. An African orchid was discovered that had a corolla nearly a foot long. Darwin inferred that there must be a moth with a tongue long enough to extract its pollen. When the moth sub-species was eventually discovered, it was given the name praedicta. Today we can identify groups of plants and their insect predators, vertebrates and their parasites, lichens composed of an alga and a fungus, and many other associations that can only reasonably be explained by co-evolution through diversification over millions of years (Padian 2008:633).
Padian includes about the amount of unwarranted hagiography you might expect. Darwin's being "less emphatic than Wallace about the pre-eminence of natural selection among other mechanisms of evolutionary change" seems good, until you reflect on the "other mechanisms" in the running -- mainly Lamarckism. And maybe Darwin didn't share Malthus' "bleak view" of the poor, but he certainly displayed a bleak view of Australian and South American native peoples in Voyage of the Beagle. Darwin should be forgiven the prejudices of the age, but it ill serves us to whitewash them.
Darwin's Origin ends famously with a passage that evokes poetic interpretation. Padian ends his essay with a quote from Thomas Hardy, one of the literary figures he describes as a recipient of Darwin's influence:
As Hardy put it: "Let me enjoy the earth no less / Because the all-enacting Might / That fashioned forth its loveliness / Had other aims than my delight." This child of the Enlightenment was well aware of more ancient world views, and humbled by what the new investigations of the cosmos revealed. Humans are animals, one species of many on the planet, bound by common ancestry to all other species, part of an ages-old dance of reproduction, accommodation, survival and alteration.
The first time, I read that last word as "alliteration." I guess it's my inner English major coming out...
References:
Padian K. 2008. Darwin's enduring legacy. Nature 451:632-634. doi:10.1038/451632a
Darwin on disease and indigenous populations
Alfred Crosby gives a short quote from chapter 19 of Darwin's The Voyage of the Beagle, and I found it interesting enough to look for the full context. Voyage is online free at several places. Because it's online I don't have ready page numbers for the quotes below, they are all from chapter 19.
The passage is part of Darwin's description of Australia, which he finds "in all respects there was a close resemblance to England: perhaps the alehouses here were more numerous." Then he takes up the subject of the aboriginals:
The number of aborigines is rapidly decreasing. In my whole ride, with the exception of some boys brought up by Englishmen, I saw only one other party. This decrease, no doubt, must be partly owing to the introduction of spirits, to European diseases (even the milder ones of which, such as the measles, [1] prove very destructive), and to the gradual extinction of the wild animals. It is said that numbers of their children invariably perish in very early infancy from the effects of their wandering life; and as the difficulty of procuring food increases, so must their wandering habits increase; and hence the population, without any apparent deaths from famine, is repressed in a manner extremely sudden compared to what happens in civilized countries, where the father, though in adding to his labour he may injure himself, does not destroy his offspring.
Besides the several evident causes of destruction, there appears to be some more mysterious agency generally at work. Wherever the European has trod, death seems to pursue the aboriginal. We may look to the wide extent of the Americas, Polynesia, the Cape of Good Hope, and Australia, and we find the same result.
The last passage (from "Wherever" to "result") was quoted by Crosby. I think the preceding paragraph gives important context to Darwin's thinking on the matter; he had the main elements (which would probably have been common knowledge), although his attribution of juvenile mortality to a "wandering life" probably would be more correctly directed toward disease as well.
But that doesn't give the after context, either. Here's what follows in the same paragraph:
Nor is it the white man alone that thus acts the destroyer; the Polynesian of Malay extraction has in parts of the East Indian archipelago, thus driven before him the dark-coloured native. The varieties of man seem to act on each other in the same way as different species of animals -- the stronger always extirpating the weaker. It was melancholy at New Zealand to hear the fine energetic natives saying that they knew the land was doomed to pass from their children. Every one has heard of the inexplicable reduction of the population in the beautiful and healthy island of Tahiti since the date of Captain Cook's voyages: although in that case we might have expected that it would have been increased; for infanticide, which formerly prevailed to so extraordinary a degree, has ceased; profligacy has greatly diminished, and the murderous wars become less frequent.
He finishes this section with some discussion of the mechanism of disease spreading by ship -- even when no symptoms were found among the crew. This idea, which Darwin attributes to Williams' Narrative of Missionary Enterprise, has become important to explain certain New World epidemics as well as those in Polynesia.
This is a great quote for Crosby to have used because it shows that many educated people were aware that disease had decimated (and was still decimating) indigenous peoples, even as historians ignored disease as a factor in their narratives of New World conquest and colonization.
But then Darwin goes straight on: for him, disease susceptibility in aboriginal peoples is not mere happenstance, but a symptom of European superiority!
Still, that's nothing compared to the final line of the chapter:
Farewell, Australia! you are a rising child, and doubtless some day will reign a great princess in the South: but you are too great and ambitious for affection, yet not great enough for respect. I leave your shores without sorrow or regret.
A second Darwin passage quoted by Crosby (1994) is from the Descent of Man, where Darwin wrote once more about the population growth in European colonies:
The remarkable success of the English as colonists over other European nations, which is well illustrated by comparing the progress of the Canadians of English and French extraction, has been ascribed to their "daring and persistent energy;" but who can say how the English gained their energy. There is apparently much truth in the belief that the wonderful progress of the United States, as well as the character of the people, are the results of natural selection; the more energetic, restless, and courageous men from all parts of Europe having emigrated during the last ten or twelve generations to that great country, and having there succeeded best.27 Looking to the distant future, I do not think that the Rev. Mr. Zincke takes an exaggerated view when he says:28 "All other series of events — as that which resulted in the culture of mind in Greece, and that which resulted in the empire of Rome — only appear to have purpose and value when viewed in connection with, or rather as subsidiary to .... the great stream of Anglo-Saxon emigration to the west."
Obscure as is the problem of the advance of civilisation, we can at least see that a nation which produced during a lengthened period the greatest number of highly intellectual, energetic, brave, patriotic, and benevolent men, would generally prevail over less favoured nations (Darwin 1871:179-180).
This serves as introduction to a section about the means by which natural selection led to the origin of mankind from animals, and civilized societies from barbarous ones. Darwin describes a kind of race-level or nation-level selection, using his "struggle for existence" metaphor. Then he returns to the topic of the Fuegans, upon whom he had spent such consideration in Voyage of the Beagle, to suggest they had been "compelled by other conquering hordes to settle in their inhospitable country, and they may have become in conseqeunce somewhat more degraded."
This raises a question for Darwin: if people can become "degraded" as a consequence of inhabiting an "inhospitable" place, perhaps it is possible that all of the "barbarous" peoples have suffered this fate sometime in the past, explaining their current states?
He spends only a couple of paragraphs on this question, with a brief statement that "civilized" peoples carry customs that link them to barbarous peoples, referring the reader to Tylor for details. I find this interesting as a reminder that Darwin operated in parallel with the beginnings of real ethnology. The section concludes with this remark, which concerns what a cladist would call the "character polarity" of civilization:
[T]here can hardly be a doubt that the inhabitants of these many countries, which include nearly the whole civilised world, were once in a barbarous condition. To believe that man was aboriginally civilised and then suffered utter degradation in so many regions, is to take a pitiably low view of human nature. It is apparently a truer and more cheerful view that progress has been much more general than retrogression; that man has risen, though by slow and interrupted steps, from a lowly condition to the highest standard as yet attained by him in knowledge, morals, and religion (Darwin 1871:183-184).
It is one of Crosby's themes that disease itself was a factor driving formerly vibrant indigenous societies into a state of collapse just prior to European colonization. The seeds of that hypothesis are there in facts that Darwin (and others) knew, but they had very different interpretations.
References:
Crosby AW. 1994. Germs, Seeds and Animals: Studies in Ecological History. M. E. Sharpe, Armonk, NY.
Darwin C. 1860. The Voyage of the Beagle. Revised edition. Online free text.
Darwin C. 1871. The Descent of Man, and Selection in Relation to Sex. Vol. 1. John Murray, London.
Diamond's Collapse in focus
The folks at Savage Minds are still whuppin' away on Jared Diamond's Guns, Germs and Steel, in posts About Yali, On cargo and cults - and Yali's question, Diamond's argument about the haves and have-nots, Malaria in Africa and Asia, and more.
Meanwhile, Mikey Brass at the Palanthsci Yahoo group put me onto this review in Reason magazine of Diamond's new book, Collapse: How Societies Choose to Fail or Succeed. It's a refreshing review in its extremely critical voice -- although in this case from the opposite side of the spectrum from anthropology.
Inside Collapse
Before going to the review, I want to give a bit of the flavor of Collapse's thesis to show why somebody might find it problematic.
Collapse is about the "collapses" of certain ancient societies. Like Guns, Germs and Steel, it is an attempt to make sense of disparate events by tying them under a common theme. The theme in Guns, Germs and Steel is geography: some societies developed more quickly because of favorable opportunities for domestication, diffusion of knowledge, and relative lack of disease.In Collapse, the theme is bad decision-making. Some societies, when faced with ecological threats, either failed to recognize them or failed to take effective steps to prevent them. These societies collapsed, and if we aren't extremely careful, so will ours.
I haven't read Collapse yet, but Edge provides the text of a 2003 lecture by Diamond, titled "Why do some societies make disastrous decisions?" that reads as a precis of the book. I'm citing some parts of it because it gives a good impression of why a reasonable anthropologist might find reasons to disagree with Diamond's argument -- and disagree strongly at many points.
He starts the lecture with a conceit, which actually appears to constitute a theme:
As every teacher knows, though, if you have a good group of students, education is also about students imparting knowledge to their supposed teachers and challenging their assumptions. That's an experience that I've been through in the last couple of months, when for the first time in my academic career I gave a course to undergraduates, highly motivated UCLA undergraduates, on collapses of societies.
After this, the lecture has a definite tone: What will shock (sorry, challenge the assumptions) of UCLA undergraduates the most? First, there's this:
Surely the Easter Islanders, of all people, must have realized the consequences to them of destroying their own forest. It wasn't a subtle mistake.
After a less problematic account of the U.S. Forest Service, Diamond offers this nugget of wisdom:
The Classic Lowland Maya eventually succumbed to a drought around 800 A.D. There had been previous droughts in the Maya realm, but they could not draw on that prior experience, because although the Maya had some writing, it just preserved the conquests of kings and didn't record droughts. Maya droughts recur at intervals of 208 years, so the Maya in 800 A.D., when the big drought struck, did not and could not remember the drought of A.D. 592.
Of course, this has a modern-day parallel:
We, too, tend to forget things, and so for example Americans recently behave as if they've forgotten about the 1973 Gulf oil crisis. For a year or two after the crisis they avoided gas-guzzling vehicles, then quickly they forgot that knowledge, despite their having writing.
I suppose government regulations on maize economy would have solved the Maya's problems, too. Or maybe most American's weren't catastrophically affected by the oil crisis, so have no rational reason to fear its recurrence (which, speaking as someone who just bought a $50 tank of gas, it still could be a lot worse).
After this, Diamond warns us of the "disastrous consequences of reasoning by false analogy" (no, I can't make this stuff up):
An example of a society that suffered from disastrous consequences of reasoning by false analogy was the society of Norwegian Vikings who immigrated to Iceland beginning in the year AD 871. Their familiar homeland of Norway has heavy clay soils ground up by glaciers. Those soils are sufficiently heavy that, if the vegetation covering them is cut down, they are too heavy to be blown away. Unfortunately for the Viking colonists of Iceland, Icelandic soils are as light as talcum powder. They arose not through glacial grinding, but through winds carrying light ashes blown out in volcanic eruptions. The Vikings cleared the forests over those soils in order to create pasture for their animals. Unfortunately, the ash that was light enough for the wind to blow in was light enough for the wind to blow out again when the covering vegetation had been removed. Within a few generations of the Vikings' arriving in Iceland, half of Iceland's top soil had eroded into the ocean.
I guess after that mistake, the collapse of Icelandic society was inevitable.
Emerging as the real bad guys in Diamond's account are "irrational behaviors" like religion ...
Religious values are especially deeply held and hence frequent causes of disastrous behavior. For example, much of the deforestation of Easter Island had a religious motivation, to obtain logs to transport and erect the giant stone statues that were the basis of Easter Island religious cults.
... self-identity ...
In modern times a reason why Montanans have been so reluctant to solve the obvious problems now accumulating from mining, logging, and ranching in Montana is that these three industries were formerly the pillars of the Montana economy, and that they became bound up with the pioneer spirit and with Montanan self-identity.
... and "psychological denial":
For example, consider a narrow deep river valley below a high dam, such that if the dam burst, the resulting flood of water would drown people for a long distance downstream. When attitude pollsters ask people downstream of the dam how concerned they are about the dam's bursting, it's not surprising that fear of a dam burst is lowest far downstream, and increases among residents increasingly close to the dam. Surprisingly, though, when one gets within a few miles of the dam, where fear of the dam's breaking is highest, as you then get closer to the dam the concern falls off to zero! That is, the people living immediately under the dam who are certain to be drowned in a dam burst profess unconcern. That is because of psychological denial: the only way of preserving one's sanity while living immediately under the high dam is to deny the finite possibility that it could burst.
Denial? Could it be that people who decide to live under a dam are people who don't have an irrational fear of engineering disasters? Who do you think expresses a greater fear of flying: people who fly on business every week, or people who have never flown?
Of course, the irony of much of this is completely unrecognized by Diamond. Someone who disagrees with his priorities is "irrational," guilty of "short-term thinking" and in "psychological denial."
He doesn't report at the end on the reaction of his UCLA undergraduates.
The review
The Reason review is by author Ronald Bailey, who has written recent books bullish on biotech and bearish on global warming. You can imagine he is skeptical of Diamond's story:
Jared Diamond's new book, Collapse: How Societies Choose to Fail or Succeed, is neither "superb" (The New Statesman), "incisive" (The Washington Post), "magisterial" (BusinessWeek), nor "insightful and very important" (Boston Herald). It is, instead, a telling example of how a smart man can be terribly misled by a fixation on one big idea.
On the Maya, Bailey points out a contradiction between Diamond's argument and the archaeology, which -- although I am far from a Maya archaeologist -- is what I thought, also:
When Diamond discusses the "collapse" of the Mayan civilization in Central America around 900 A.D., he hauls out the standard Malthusian explanation: "It appears to me that one strand consisted of population growth outstripping available resources: a dilemma similar to one foreseen by Thomas Malthus in 1798." This population/resource imbalance led to civilization-destroying warfare, which Diamond declares is "not surprising when one reflects that at least 5,000,000 people...were crammed into an area smaller than the state of Colorado." Before nodding your head in sage agreement with this analysis, keep in mind that Colorado itself is today crammed with 4.5 million people whose standards of living are vastly more luxurious than those of 10th-century Mayan nobles and peasants.
Anthropologist Lisa Lucero of New Mexico State University at Las Cruces told USA Today that she disagrees with Diamond's analysis of the "collapse" of the Mayan civilization: "There's no evidence for massive violence and massive disease among the classic Maya." She believes the evidence indicates that the Mayans simply moved on because of widespread drought.
On the subject of wrong archaeological insights, Benny Peiser of Liverpool John Moores University has a paper that presents a fuller story of the Easter Island "collapse". Here's part of the abstract:
According to Diamond, the people of Easter Island destroyed their forest, degraded the island's topsoil, wiped out their plants and drove their animals to extinction. As a result of this selfinflicted [sic] environmental devastation, its complex society collapsed, descending into civil war, cannibalism and self-destruction. While his theory of ecocide has become almost paradigmatic in environmental circles, a dark and gory secret hangs over the premise of Easter Island's self-destruction: an actual genocide terminated Rapa Nui's indigenous populace and its culture. Diamond, however, ignores and fails to address the true reasons behind Rapa Nui's collapse. Why has he turned the victims of cultural and physical extermination into the perpetrators of their own demise? This paper is a first attempt to address this disquieting quandary. It describes the foundation of Diamond's environmental revisionism and explains why it does not hold up to scientific scrutiny.
The paper is freely available as a PDF. Other counter-arguments to Diamond's archaeology and social anthropology will likely emerge also.
The theme of Bailey's review is that Diamond ignores the ways that greater economic diversity, political freedom, and freedom of thought make societies stronger and more resistant to collapse. As he puts it:
As ecology teaches us, the simplest ecosystems are often the most fragile. Similarly, our modern globally interconnected economy that can draw upon a wide array of resources is far more stable and robust than either the fragile pre-modern or the marginally modern societies cited by Diamond.
This contrast is marked in Diamond's comparison of "overcrowded" Haiti and the neighboring, wealthier, Dominican Republic:
This simplistic analysis doesn't stand up to scrutiny. Diamond overlooks an even more "overpopulated" island right next door, Puerto Rico. Its population density is almost twice that of Haiti, at 1,120 people per square mile. By 1900 Puerto Rico's primary forests had been reduced to 1 percent of their original extent, and in 1953 its secondary forests covered only 6 percent of the island. Today 32 percent of Puerto Rico is forested, and the island's per capita GDP is $16,800 per year.
Why is Puerto Rico so much better off than its neighbors? In a word, institutions. Diamond vaguely recognizes the importance of social and political institutions, but his analysis doesn't go much deeper than arguing that Haitian dictators have been more rapacious than Dominican dictators. In fact, the last two centuries have shown that the more a country adheres to the rule of law, protects private property, reduces bureaucratic corruption, nurtures a free press, permits free markets, engages in trade, and allows democratic politics, the less likely it is to suffer from the Malthusian horrors of plagues, famines, and civil wars. What Haiti and Rwanda have in common is not just dense populations but shattered social and political institutions. What the United Kingdom, the Netherlands, and Puerto Rico have in common are not only dense populations, but adequately effective social and political institutions.
It's a good review, that puts the critical issues at the front and cuts broadly. I especially like the passage about farmers and parasites.
No doubt there is much that is good in Diamond's book. My impression, for example, is that he does stress the importance of political representation in decision-making and other aspects of freer societies that Bailey wants more attention to.
But the parts that are bad are just wrong. The peril of false analogy is that sometimes history doesn't repeat itself, because it really is different this time. Perhaps we're not living in such a lucky time, but even if not, I doubt we need another Jeremiad based on faulty social and archaeological arguments.
Backhoe history
The sad part of this story is that nobody cares about the identity of the other guy:
The mystery surrounding the skulls began in 1826, 21 years after [Friedrich] Schiller died in Weimar, when the local mayor had 23 skulls retrieved from a mass grave in which the poet was buried. Many eminent people at that time were buried in mass graves.
The mayor identified the largest skull as Schiller's and it was brought to the home of his contemporary Goethe, who wrote a poem about it, according to German scholar Albrecht Schoene.
In 1911, another skull was disinterred from the mass grave which researchers claimed was the real one. A long debate amongst academics, historians, medics and anthropologists about the identity of the skulls ensued.
So, naturally, they're digging up his relatives and plan to sample their DNA for a match.
I suppose it's a real advance when we go beyond testing live people who are purporting to be long-dead celebrities, against the live relatives, and move on to testing dead skeletons that people purport to be celebrities against dead relatives. How long can it be before we establish a catalog of dead celebrities' DNA profiles?
What would you do with the body of a Viking queen?
Norwegian scientists are digging her up for DNA testing:
SLAGEN, Norway - Archaeologists exhumed the body of a Viking queen on Monday, hoping to solve a riddle about whether a woman buried with her 1,200 years ago was a servant killed to be a companion into the afterlife.
As a less gruesome alternative, the two women in the grass-covered Oseberg mound in south Norway might be a royal mother and daughter who died of the same disease and were buried together in 834.
"We will do DNA tests to try to find out. I don't know of any Viking skeletons that have been analyzed as we plan to do," Egil Mikkelsen, director of Oslo's Museum of Cultural History, told Reuters at the graveside.
Well, it's a pretty trivial question for genetics. Here's a more interesting one: Assuming it's not her daughter, which woman is more genetically similar to living Norwegians? They may be digging up kings and queens all over Europe to answer that one...
If you knock, leave them an offering:
The archaeologists placed a Norwegian 20-crown coin - dated 2007 and with a picture of the prow of the Oseberg ship on one side - in the sarcophagus to show any future generations when the grave had been disturbed.
Admit it: if you were digging up a ninth-century grave and found a coin from 1653, it would freak you out! Maybe future archaeologists will just assume this is one of those early twenty-first century "natural" burials.
A two or a nine?
I read this post by Grant McCracken some months ago, and I wanted to remind myself of it on September 1. So here it is:
You can't imagine soldiers (prisoners?) coming here and knocking down thousands upon thousands of grave stones. And what if you did imagine it? You'd be trapped and you couldn't ever get back. You would have tipped into their insanity or your own.
OK, that makes the relevance of the date obvious, but there's a poignant story there about an ambiguous headstone that deserves reading.
Linnaeus and species fixism
I think many biologists have a pretty vague picture of why Linnaeus was important. To some, he probably seems banal -- how exciting could it be to make all those lists of species, just endless lists, over and over? "Yeah, sure, somebody had to come up with a classification system, but mainly, I'm sure glad it didn't have to be me!"
Other biologists may view Linnaeus through a lens clouded to some extent by the later development of evolutionary theory. Linnaeus is certainly the most familiar, and possibly the most apt, example of essentialist, typological thought prior to Darwin. His categorizations depended on typological features, and even today definitions of species based on morphological types are often called "Linnean species."
But several aspects of Linnaeus' writings belie this stereotype. For one thing, especially later in his career, Linnaeus became convinced that new species actually do appear over time, particularly through hybridization. I'll have more on that in a later post.
Another thing is that before Linnaeus and his contemporaries, people didn't approach biological diversity with an essentialist framework. An essentialist view of species required the assumption that species were fixed, not changing over time. A good source discussing the importance of Linnaeus in the formulation of species fixism is Ronald Amundson's book, The Changing Role of the Embryo in Evolutionary Thought.
I posted on Amundson's take on Weismann a couple of years ago. I think his take on Linnaeus and species fixism — although short — was the part of the book that struck me the most, mainly because of its heterodoxy in contrast to the historical work of Ernst Mayr and others.
To begin, he lays out the conventional story:
Modern narratives of the history of evolutionary biology take place against the background of species fixism. The story goes like this: The historical discovery of evolution was the overthrow of species fixism. From ancient days, Western intellectuals had conceived of a stable and unchanging world that had been created by God in pretty much the condition it now exists. Beginning in the early seventeenth century, traditional beliefs were shaken by a series of challenges to the world's constancy and stability ... [e.g., Copernican cosmology, geological process]. In this narrative, the fixity of species was the last vestige of the stable and unchanging world of the ancients.... Darwin's job was like that of Copernicus — the overthrow of an ancient belief in stability.
That's the story, but it's not true. The Western tradition was indeed centered on an unchanging world but the fixity of species was not a part of that world. It became widely accepted for the first time both among naturalists an theologians during the eighteenth century, only about a century before Darwin (Zirkle 1951:48-49; Zirkle 1959:642). Carl Linnaeus is widely known for his unequivocal statements of species fiexism and special creationism. It is less widely recognized that Linnaeus was one of the innovators of fixism. Prior to Linnaeus and his botanical colleagues, beliefs in transmutation and spontaneous generation were extremely widespread (Amundson 2005:34-35, emphasis in original).
For his story, it is important for Amundsen to spends some time describing belief in transmutation, and he devotes three pages to various illustrations of how widespread the belief was. I especially like the following passage on the "barnacle goose," which serves to set the background against which species fixism seems a starkly modern view:
Even more dramatic transmutations were commonly accepted. To the modern ear they strain the boundary between myth and honest empirical belief. The story of the phoenix was often treated skeptically, but it was no less extreme than the barnacle goose. The Oxford English Dictionary still contains the renaissance term anatiferous: "producing ducks or geese, that is producing barnacles, formerly supposed to grow on trees and dropping off into the water below, to turn into tree-geese" (Hacking 1983:70). Philosopher Ian Hacking uses the term anatiferous to illustrate incommensurability: Wht in the world could those people have been thinking of? But this was an honest factual belief. Raven quotes the sixteenth-century author Scaliger, who reports "as a thing he himself has seen" the stories "falsely told of the phoenix but veraciously of the Bernacle [sic] Goose" (Raven 1953:204).
Most people, sometime during the slow years of high school biology, learn about Francesco Redi and Lazzaro Spallanzani — Redi put rotting meat in a jar with gauze over the top, proving that maggots don't spontaneously generate; Spallanzani showed that microbes don't spontaneously generate but come from the air and may be killed by boiling. Both, and others such as van Leeuwenhoek, helped to roll back the idea that life was generated from nothing. Still, the problem with refuting spontaneous generation is that you have to be able to see all possible influences. Not until Pasteur was the idea of microbial spontaneous generation finally refuted once and for all.
Now, to bring the connection to Linnaeus -- Spallanzani's work on boiling and microbial transmission was in the 1760's. Spallanzani also demonstrated that sperm was necessary for reproduction (at least in mammals), performing the first known artificial inseminations (of dogs) -- all this in 1779, just after Linnaeus' death.
In other words, in Linnaeus' day, spontaneous generation and transmutation were still potent ideas. For animals in particular — not Linnaeus' strong point — they were quite difficult to disprove. Even the causes of reproduction were somewhat mysterious, and what radical transmutations were possible at birth were well-known.
Botanists, including Linnaeus and his contemporaries, were in a much better position to establish the limits to variation. In this respect, Linnaeus' close focus on the sexual processes of plants and consequent classification were hugely important. Botanists' long experience in plant breeding experiments, and with the relative ease of exchanging seeds and cuttings across Europe, they developed an ability to assess the properties of hybrid strains and varieties -- even more than a hundred years before Mendel.
Spontaneous generation and transmutation are ultimately linked, since both predict very particular things about reproduction and the nature of parent-offspring resemblances: like from like, and nothing from nothing are joined principles.
Seen in the context of prefixist theories of spontaneous origins and transmutations, species fixism was a progressive scientific development. Beliefs in spontaneous generation persisted into the nineteenth century, but they were restricted to smaller and smaller organisms as time passed (Roe 1981). Fixism was established for nonmicroscopic plants and animals around 1750, primarily on the basis of plant breeding experiments. Plant variation had been an especially common area of transmutationist beliefs. The careful and controlled breeding programs of Linnaeus and others established fixism among most naturalists (Amundsen 2005:37).
Amundsen argues for Linnaeus' dual importance -- not only as the innovator of his system of taxonomic descriptions and classification, but also as an experimenter and gatherer of information about botanical forms:
Linnaeus's fixism, like that of his contemporaries, was based on evidence that had been painstakingly gathered from a vast network of horticultural gardens across Europe. The old transmutationist beliefs in the influences of climate on plant forms had been tested by returning the modified forms to their original locations. The plants then reverted to their original forms. Experiments had been done in the production of hybrids ("bastards"), and the limitations on viability and fertility had made it seem exceedingly unlikely that this was a cause of new species (Amundsen 2005:40).
This "painstaking" work underlay the basic scientific description of variability under human domestication between Linnaeus and Darwin. Plants might be changed in new environments, and they might be bred or hybridized by humans, but they would revert to their wild, "natural" state. Stamos (2005:91) discusses Linnaeus' view of this reversion:
Linnaeus, for example, exhibited a belief in the law of reversion in his Critica Botanica (1737) when he wrote that "every day new and different florists' species arise from the true species so-called by botanists, and when they have arisen they finally revert to the original forms. Accordingly to the former have been assigned by Nature fixed limits, beyond which they cannot go: while the latter display without end the infinite sport of Nature" (Ramsbottom 1938: 200n).
And Stamos (ibid.) quotes further from Jussieu, in many ways Linnaeus' taxonomic successor:
Jussieu too, in his Genera Plantarum (1789), expresses a belief in the law of reversion. Although a species, he says, "is occasionally subverted for a while by chance or human industry; that is to say, some individuals may vary one from another on account of location or climate or disease or cultivation . . . But these varieties, obeying the law of nature, . . . return to the primordial species, their character restored, if other factors do not interfere" (Stevens 1994: 340-341).
Hence, reversion served as evidence that species are fixed, and that their variation is transient. Botanical experimentation supported the essentialist view of species, against the tranmutationist view.
The belief in fixism was important to the classification -- if organisms could readily transmute to radically different forms, then a "natural" classification of them would likely be impossible. Linnaeus' classification was not itself a "natural system", but his hierarchical use of characteristics -- and recognition that reproductive features were the basis of large-scale similarities in plants -- put the outline of such a system in view.
References:
Amundson R. 2005. The changing role of the embryo in evolutionary thought: roots of evo-devo. Cambridge University Press, Cambridge UK.
Stamos DN. 2005. Pre-Darwinian taxonomy and essentialism -- a reply to Mary Winsor. Biol Phil 20:79-96. doi:10.1007/s10539-005-0401-9
"Botanical pornography"
Not the work of Georgia O'Keefe, but of Carl Linnaeus according to this NY Times article observing the 300 years since his birth. The birthday was last week, May 23, (taking into account the eighteenth-century shift to the new calendar). So I've put together a few Linnaeus sources:
First, the Times article (by James Barron) reviews a meeting at the New York Botanical Garden:
The man who mentioned "botanical pornography" was Robbin C. Moran, a Linnaeus expert and the garden's curator of ferns. He described Linnaeus as an egotist who once declared, "God creates, Linnaeus arranges."
...
Linnaeus is known for some firsts of his own, besides introducing his system of nomenclature for living things. He was the first to use a centigrade thermometer the way it is used today. (Anders Celsius was the first to divide the range between the freezing point and boiling point of water into 100 units, but made zero the boiling point and 100 the freezing point.)
Linnaeus was also the first person who figured out how to grow bananas in Europe. (Imitating the monsoon climates of Asia, he let the soil dry out, then bombarded it with water.)
If you're having trouble figuring out the name thing (Linnaeus, Carolus, Carl von Linné, etc.), Wikipedia straightens it all out. And they have this great engraving of Linnaeus decked out in Lapp tucker after a trip to the north:
That's much more interesting than the usual wigged-out portrait:
Although he does look like a kindly old fellow there. Bora Zivkovic has a bit more on the lighter side of Linnaeus, pointing out that he was the first to come up with the idea for a floral clock -- a garden arrangement with flowers that open or close at specified times of the day, hence providing a rough (and pretty) timepiece.
The article in the current National Geographic on Linnaeus, by writer David Quammen, explains a bit more about the "pornography" reference:
His classification of the vegetable kingdom was more innovative, more comprehensive, and more orderly. It became known as the "sexual system" because he recognized that flowers are sexual structures, and he used their male and female organs — their stamens and pistils — to characterize his groups. He defined 23 classes, into which he placed all the flowering plants (with a 24th class for cryptogams, those that don't flower), based on teh number, size and arrangement of their stamens. Then he broke each class into orders, based on their pistils. To the classes, he gave names suhc as Monandria, Diandria, Triandria (meaning: one husband, two husbands, three husbands) and, within each, ordinal names such as Monogynia, Digynia, Trigynia, therby evoking all sorts of scandalous ménages (a plant of the Monogynia order within the Tetrandria class: one wife with four husbands) that caused lewd smirks and disapproving scowls among some of his contemporaries. Linnaeus himself seems to have enjoyed the sexy subtext (Quammen 2007:84).
I originally wrote this up last week as part of a much longer post on Linnaeus, and I've decided to break it up into a short series. All the posts will be available here as they appear, but as I write this, this is the only one.
References:
Quammen D. 2007. A passion for order. National Geographic. June, 2007, pp. 73-87.
Paleontology in the classical world, reviewed
Afarensis reviews the book The First Fossil Hunters: Paleontology in Greek and Roman Times, by Adrienne Mayor:
In Chapter Three, Mayor discusses discovery of bones in the Greek Pre-classic and Classic. Classical scholars should be familiar with these in a different context. For example, the Spartan discovery of the bones of Orestes or the shoulder of Pelops kept at the sanctuary of Olympia. The bones of Theseus were discovered by the Athenians (who also swiped the bones of Oedipus from Thebes). As Mayor points out there was a veritable bone rush at that time with skeletons of heroes popping up all over the place. One of the traits that united these finds was the large size of the bones. The ancient Greeks felt that their heroes were larger in stature than they were. An idea that traces back to Hesiod's Works and Days (where he discusses the five ages of Man) and probably earlier. Over time, according to the ancient Greeks, humans have grown shorter. So when giant bones were discovered - especially those that looked vaguely human - they were interpreted as the bones of Greek heroes. The Roman emperors Augustus and Tiberius also collected bones. What unites a lot of these discoveries is that they come from areas with a lot of fossils - mainly from the Miocene to the present and composed of large megafauna such as mammoths, mastodon, giraffe and rhinoceros to name a few.
According to the review, the book includes a number of archaeological instances where fossils were found in classical or preclassical contexts. I like Afarensis' point that despite the possibility that such finds guided mythological formulations of ancient giants and the like, classical philosophers "made little mention of such discoveries."
It makes you wonder what might have been done with the same evidence and the right person. As I was reading the review, I was reminded of Thomas Jefferson and the mastodon, and I went looking up some details:
In 1784, Jefferson had bravely argued against Buffon's statement that the "mammoth" bones of North America represented the same species as those of the modern elephant. Lacking professional confidence, Jefferson successfully enlisted the support of Ezra Stiles, president of Yale College, but Buffon never wavered in his identification. Ultimately, Jefferson's position was sustained by Georges Cuvier (1769-1832), the brilliant French anatomist, who recognized the bones as those of the mastodon (Coonen and Porter 1976:747).
In the eighteenth century, those knowledgeable about fossils and anatomy to a sufficient degree to argue such facts were rare. In classical times, such people simply did not exist. Considering the spacing of natural historians in the late eighteenth century (a handful per nation-state), it is probable that no conversation could have been sustained among them without technologies, particularly printing. This is particularly true because the comparative study of such remains requires visual representations -- diagrams at a minimum; ideally casts or original specimens -- which could hardly have been distributed to a critical number of people very much earlier in time.
It's no surprise that there was some change in mindset between classical times and the Enlightenment. Still, one wonders which innovations were essential to the growth of science. As indicated by the review, classical peoples were evidently interested in ancient remains and even collected them. This acquisitiveness had increased by the eighteenth century -- with a substantial number of avocational antiquarians -- but was hardly different in character.
The interpretation that ancient mastodons and other such fossils were the remains of an ancient race of "giants" was perfectly straightforward. Although clear evidence is rare, it seems probable that every culture with exposure to such ancient bones arrived at similar mythology-inspired conclusions. In Europe and America, such explanations persisted in Jefferson's day. Even post-Renaissance antiquarians arrived at semi-mythological explanations for ancient artifacts -- for instance, ancient stone tools as "thunderstones." Most straddled the boundary between mythology and naturalism.
The Enlightenment was the first point at which the tide of science was capable of formulating and testing a coherent alternative. The fossil record provided clear evidence directly on the origins of the earth and its history, and the logical options were clear enough once some connection between rock layers and time was made. As an example, Jefferson already knew enough to predict overkill as a cause for the disappearance of ancient megafauna:
Jefferson argued that an animal as large as the "great-claw" [the giant sloth] must always have been rare because, he reasoned, the "ordinary economy of nature" would provide "sufficient barriers" to large populations:
If lions and tygers multiplied as rabbits do, or eagles as pigeons, all other animal nature would have been long ago destroyed, and themselves would have ultimately extinguished after eating out their pasture (Jefferson 1799, p. 256)
Referring to Africa, Jefferson also claimed that a "new population" -- namely, man -- tended to drive off large animals to the continental interior. He suggested that in North America the pressure of Indian hunters had accomplished the same shift. This analogy was the rationale behind his seemingly whimsical instruction that Lewis and Clark look for signs of the living mammoth west of the Mississippi. Furthermore, Jefferson hinted that, by preferential hunting of these giant animals for an obviously great store of meat and hides, the Indians had probably exterminated them (Coonen and Porter 1976:747).
Two assumptions had crystallized by the eighteenth century: exponential (or "Malthusian") growth of populations, and the progressive decay of ancient things. Both assumptions are products of everyday observations that may have gotten more ordinary over time.
Old cities decay and are replaced; old things are buried and unburied. Sometimes the cities themselves get higher as a result -- a fact increasingly known as excavations into the subterranean layers of cities (for foundations and sewers) increased. The classics surely knew these things, but the recognition of old things must have grown as human history piled itself up into deeper and deeper layers.
The fleeting nature of life and youth was a standard of classical authors, but the disappearance and decay of entire civilizations was particularly part of the Enlightenment zeitgeist. Perhaps it was no accident that the beginnings of paleontology coincided with Edward Gibbon's Decline and Fall of the Roman Empire. Lost signs of ancient things became a staple of early Romanticism, and several scenes in Wordsworth's work wear on the implications of hidden histories. Better-known is Shelley's "Ozymandias," written in 1817:
I met a traveller from an antique land
Who said:—Two vast and trunkless legs of stone
Stand in the desert. Near them on the sand,
Half sunk, a shatter'd visage lies, whose frown
And wrinkled lip and sneer of cold command
Tell that its sculptor well those passions read
Which yet survive, stamp'd on these lifeless things,
The hand that mock'd them and the heart that fed.
And on the pedestal these words appear:
"My name is Ozymandias, king of kings:
Look on my works, ye mighty, and despair!"
Nothing beside remains: round the decay
Of that colossal wreck, boundless and bare,
The lone and level sands stretch far away.
A paleontologist reading the poem may find that it evokes a great fossil eroding from a desert badlands; replace "Ozymandias" with "Tyrannosaurus", and the verse sums up the present-day attitude toward the dinosaurs, far more than that toward ancient Egypt.
Imperial Rome, at over a million souls, was the apotheosis of classical population growth, but a clear reflection on the implications of such growth may have needed post-medieval mathematical insights or monetary and economic insights. London reached its first million shortly before 1800 -- the first city to do so since classical Rome. By that time, economics and mathematics were ready to infer the consequences of rapid population growth.
We now know that both insights were necessary for evolutionary theory to emerge, and the strands of evolutionary thought emerged before Darwin in the Enlightenment. This short-term history of thinking in the eighteenth and nineteenth century certainly benefits from considering just how much had changed in human existence since classical Greece and Rome.
References:
Coonen LP, Porter CM. 1976. Thomas Jefferson and American biology. BioScience 26:745-750.
Vaccinator in chief
I was checking on the Thomas Jefferson mastodon story for the last post, and I came across an episode I hadn't been aware of. After Edward Jenner's development of the smallpox vaccine in England, it was Jefferson who advocated its use and spread in America. And more:
Jefferson became as directly involved as if he had been the health commissioner in a small city. At the time, however, he presided over five million citizens. As a public endorsement of the procedure, he had his entire family vaccinated. But he did not stop there; in 1800 he received cowpox vaccine from [Benjamin] Waterhouse and turned it over to a Dr. Grant in Washington. When it was learned that the substance was inactive (the virus had died), Jefferson himself suggested a new and successful method for maintaining live cultures during shipment (Martin 1952; pp. 39-41).
He personally directed and encouraged the distribution of vaccine to various parts of the country. On one occasion, when Chief Little Turtle and nine of his braves came to Washington on official business, Jefferson persuaded the entire party to be vaccinated. Beyond that, he sent a virus preparation with them for inoculating others in their tribe. When Lewis and Clark left on tehir long trek into the unknown northwest, they were counseled, "carry with you some matter of the kine pox. ... Instruct them [the Indians] ... in the use of it" (Martin 1952, p. 63) (Coonen and Porter 1976:747).
If you had a president in a piece of fiction who did this sort of thing, nobody would believe it. Which is sad.
References:
Coonen LP, Porter CM. 1976. Thomas Jefferson and American biology. BioScience 26:745-750.
Martin ET. 1952. Thomas Jefferson: Scientist. Henry Schuman, New York.
Lucky Lindy's organ pumps
What an interesting book review by Abigail Zuber, of a new book about Charles Lindbergh's medical collaboration with famous surgeon Alexis Carrel. Lindbergh designed pumps to keep organs alive outside the body:
And that thyroid gland was more than just preserved: still dutifully producing thyroid hormone, it seemed eerily alive. It lasted only a few weeks, but it was soon replaced by a row of other pump-maintained organs, including a cat's ovary that continued to ovulate on the pump. Small wonder the newspapers of the time went wild: "One Step Nearer to Immortality," one headline read.
Crazy. Then, the two directed their energies toward eugenics:
The scientific success only fueled Lindbergh and Carrel's philosophic zeal: if immortality was indeed on the horizon, it certainly should not be for everyone. In his 1935 best seller "Man, the Unknown," Carrel urgently argued for the creation of biologic classes, with the weak and sick at one end, and the strong and fit (long might they live, propagate and receive new organs as needed) at the other. The sorting was to be accomplished by a council of scientific experts much like himself.
The book is called The Immortalists, by David Friedman.
Coincidence or homology?
Remember that story from last month about how fruit flies have some kind of free will because they navigate their flight in nondeterministic directions?
Only after the team analyzed the fly behavior with methods developed by co-authors George Sugihara and Chih-hao Hsieh from the Scripps Institution of Oceanography at UC San Diego did they realize the origin of the fly's peculiar spontaneity. "We found that there must be an evolved function in the fly brain which leads to spontaneous variations in fly behavior" Sugihara said. "The results of our analysis indicate a mechanism which might be common to many other animals and could form the biological foundation for what we experience as free will".
Well, here's a passage I happened across this morning in Ontogeny and Phylogeny, discussing the developmental theories of Etienne Geoffroy Saint-Hilaire and his student, Etienne Serres:
Geoffroy tried to compare the exoskeleton of arthropods with the internal skeleton of vertebrates (relegating insects to a life within their own vertebrae); he sought identityin the location of parts by likening the basic design of vertebrates to a worm turned over (yielding both the happy circumstance of dorsal nerve cords and such problems as a mouth above the brain). Serres agreed, attributing the inversion to a reversed position of the embryo relative to the yolk (1860, pp. 825-826).
Yet Serres acknowledged the difficulty of comparing adults and set out to prove the unity of plan on another basis: by the fact of recapitulation. The nervous systems of vertebrates and invertebrates have a common design (though this may shock some physiologists since it implies that invertebrates have a will). This identity is not apparent in adult vertebrates, but transient stages of the vertebrate fetus repeat the permanent configurations of invertebrate systems and display thereby a unity of plan (Gould 1977:48, emphasis added).
I'm not sure why the design of the vertebrate nervous system necessarily yields a "will," but of course the new results show a functional commonality that may reflect the developmental and genetic homologies.
References:
Gould SJ. 1977. Ontogeny and Phylogeny. Harvard University Press, Cambridge MA.
Dobzhansky on Weidenreich's species concept
I found this passage in the discussion following T. Dale Stewart's paper, "The problem of the earliest claimed representatives of Homo sapiens," from the 1950 Cold Spring Harbor Symposium on Early Man.
DOBZHANSKY: The great variability of the Neanderthaloids, so ably described by Drs. McCown and Stewart [McCown's paper immediately preceded the one under discussion], bears upon one of the basic problems of human descent. It is now clear that the Neanderthaloids and the so-called sapiens type were at no time two reproductively isolated species, but rather component races of a single species. Some modern populations may carry genes that were present in the Neanderthaloids, and other moderns may not carry such genes. But this does not mean, of course, that mankind consists of races descended from Neanderthaloids and other races which came from the sapiens type contemporaneous with the Nenderthaoids. In general, the old anthropological alternative of monogenic versus polygenic descent of man ceased to exist when considered from the vantage point of the present evolution theory. Different populations (races) of a polytypic species may be descended largely from different races of the ancestral species and may differ in some genes in which these ancestral races differed. And yet, a polytypic species may still evolve as a single genetic system. Favorable mutants or gene combinations arrived at in one part (race) of such a species may, under the influence of natural selection, eventually spread to all other parts and thus become a common property of the entire species. Thus, local autonomy of the gene pools of racial populations does not preclude retention of a basic unity of the species as a whole. I would like to point out that this view agrees quite well with the conclusions reached by the late Weidenreich on basis of purely morphological analysis of pre-human populations. This is worth while [sic] stressing because Dr. Weidenreich has sometimes used expressions which seemed to put him close to the old-fashioned polygenist camp, which he actually rejected absolutely (Dobzhansky, following Stewart 1950:106-107).
I love these discussions, which often included exactly the people whose opinions you would like to see, and sometimes some surprising ones. For instance, after Dobzhansky in this particular discussion, Joseph Birdsell and Stewart had an exchange about the implications of the fluorine dating of Piltdown for interpreting variability within modern humans (Birdsell's point being that such an apelike jaw must extend the variability of Homo sapiens even further if it is actually recent! Ha!)
And they often jumped off on tangents, like the Piltdown tangent, which remind you of the other things that people cared about besides the immediate topic. I think it's the closest thing to science blogging that the 1940's and 1950's had to offer!
References:
Stewart TD. 1950. The problem of the earliest claimed representatives of Homo sapiens. Cold Spring Harbor Symp Quant Biol 15:97-107, comments following.