Monday, July 12, 2010

Of eggs and sperms and misunderstood worms

I’ve been reading quite a few popular science and narrative history books lately, with some rewarding results. A while ago I finished Matthew Cobb’s very engrossing The Egg & Sperm Race, about the 16th and 17th century European biologists who gradually unraveled the secrets of birth, including facts about sexual organs and reproduction that we today take for granted.

It isn’t easy to relive and then recreate the worlds inhabited by people who existed four hundred years ago, and I was amused by Cobb’s own approach to understanding his characters: he states that he tried to picture them by imagining which Hollywood actor would portray them best. (Cary Grant gets a prominent role, which automatically gave this book a gold star in my book, even before I had reached the Prologue.) But that lightweight remark aside, The Egg & Sperm Race really does make a dense subject interesting for the layperson, bringing alive such figures as Francesco Redi (whose careful experiments with putrefying matter showed that insects were bred from other, similar-looking insects – now there’s an idea!), Athanasius Kircher (an earnest but very credulous man who wrote carefully detailed books describing mythical beast and subterranean humans), Reinier de Graaf and Jan Swammerdam (who made pioneering contributions to the understanding of the human egg, though they also spent much time bickering with each other over who discovered what first). Their stories add up to a narrative comparable to that of a sharply plotted thriller. The passage where a Dutch draper named Antoni Leeuwenhoek uses his microscope to examine his own semen (less than “six beats of the pulse” after ejaculation), and discovers “a vast number of living animalcules...moving about with a snake-like motion of the tail”, reads like a mystery heading towards its resolution, even though the present-day reader knows beforehand what he’s going to see.

With the benefit of hindsight, some of the hypotheses made by these men, and some of their experiments, seem ludicrous. They were often badly mistaken on important matters, and in some cases the mistakes created scientific bottlenecks that took decades or even centuries to clear. But one shouldn’t underestimate their achievements: they worked in the face of enormous odds, including primitive technology, theological opposition, widespread superstition and misunderstanding. To put this in context, consider that even the most brilliant thinkers of the time genuinely believed that insects, and some small animals, came into being through “spontaneous generation”. There were proposed “recipes” for creating toads (they could be fashioned from the corpses of ducks placed on a dung heap!) and snakes
(put a woman’s hair in a damp but sunny place). In an earlier age, even Leonardo da Vinci – a genius with a very scientific bent of mind, known for conducting dissections of cadavers – thought that semen originated in the male brain and traveled via the spinal cord, and that there was a vessel linking a woman’s nipples to her uterus (da Vinci's depiction of copulation is on the left: "I expose to men the origin of their first, and perhaps second, reason for existing," he wrote on the side of the drawing in his mirror script).

Reading The Egg & Sperm Race, it occurred to me that there’s often a big gap between the psychological acuity of the great fiction writers of yore and the relative underdevelopment of human knowledge in their era. Here’s an example. William Shakespeare is rightly considered one of the finest chroniclers of the human condition, a writer with extraordinary insight into the hearts and minds of men; his words still call out to us across the centuries, giving us a language to express complex thoughts in. Yet, from the perspective of scientific understanding, the world was a relatively backward place during Shakespeare’s lifetime, as many of the anecdotes in Cobb’s book make plain. When I think of the lines “Your worm is your only emperor for diet. We fat all creatures else to fat us, and we fat ourselves for maggots”, what now strikes me is that the playwright who wrote it had absolutely no idea where worms came from; if he ever gave the matter a thought, he probably believed – like everyone else in his time – that they simply grew out of mud-heaps!

But it’s equally true that great writers, by virtue of intuitive, unschooled wisdom, can sometimes provide cues for subsequent generations of thinkers. There’s a wonderful anecdote in The Egg & Sperm Race where a biologist derives inspiration from an episode in Homer’s Iliad – the passage where Achilles voices his fear that flies would breed worms in the wounds of the dead Patrocles. Homer’s lines, written over 2,500 years earlier, seemed to contradict the conventional wisdom that new flies simply “arose” from decaying matter, but the spark they lit in the scientist's mind indirectly hastened an important discovery. It’s an example of a brief meeting of minds between classical poetry and modern biology. Who would have thought it.

[Matthew Cobb's blog is here. Images of places/things mentioned in the book here]

12 comments:

  1. the relative underdevelopment of human knowledge in their era

    What's striking is that the advances in more abstract sciences like mathematics have been far more rapid when compared to advances in technology-dependent life sciences.

    Practically everything we learn in math upto early undergraduate level today has been known for a few hundred years! Estimates of Pi upto 11 decimal places were around back in 14th century!

    Progress has been much slower in life sciences mainly because of the lack of technological wherewithal more than anything else. Even the most primitive microscopes have a history of barely 300 years.

    That's why I think too much is made of the extent to which "superstition" and "theological opposition" slowed scientific progress. I'm reminded of that much-quoted Orson Welles quote in The Third Man about the astonishing cultural progress in Italy notwithstanding the uncongenial political setup.

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  2. It's after reading things like this one realises how far humanity has come. And then you switch on the TV.

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  3. Shrikanth: I did mention "primitive technology" first in the list of enormous odds faced by these men, and I agree that it was the most important impediment to clearer understanding of the life sciences. But I don't quite agree that too much is made of the extent to which "superstition" and "theological opposition" slowed scientific progress. Religious blinkers and the insistence on clinging to beliefs that originated in holy books still find a way to undermine science, even in our own times.

    Just one small, specific example: consider how a large percentage of the world's population is still either unaware of or full of misconceptions about evolution and natural selection. Consider the continuing popularity of questions like "If man evolved from monkeys, why are monkeys still around?" and "How can the complexity of life be a result of mere chance?" - both of which betray a complete non-grasp of what the evolutionary theory is. That sort of thing comes directly from concerted and manipulative efforts by religious authorities to keep their followers from understanding how science really works and what it has discovered.

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  4. Phoenix: ha ha. In fairness though, one should point out that there are some good, informative programmes on the History Channel, Animal Planet, etc. Assuming anyone watches them...

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  5. J'wock:

    both of which betray a complete non-grasp of what the evolutionary theory is. That sort of thing comes directly from concerted and manipulative efforts by religious authorities

    Somewhat disagree. I'd like to think that Evolution, like a lot of scientific concepts, is more complex than it seems and is not likely to be understood by everyone.

    Just to draw an analogy with Math:
    Thanks to equation drills in high school, practically all of us know to differentiate and integrate. But not many may have actually grasped calculus well enough to explain integration in layman's terms.

    Same is true for Evolution. After all, it wasn't something self-evident to Darwin to begin with. If a lot of people have trouble understanding it, so be it!
    Why are we so desparate to democratise science!

    I'd rather let people think as they like about the origin of species instead of drilling them with theories that they're unlikely to grasp anyway. Received wisdom is a bad thing. Be it the blind acknowledgment of evolution or the blind belief that Citizen Kane is the greatest movie of all time just because AFI told you so.

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  6. Shrikanth: sorry, but I think the last paragraph of that comment is ludicrous. In a discussion pitting scientific exploration and understanding against the insularities of religion, it's very odd that you choose to say "received wisdom is a bad thing" in the scientific context. I'd say that line is much, much more applicable to people unquestioningly receiving the "wisdom" of a theological tradition over hundreds of generations.

    And no one, least of all a scientist, would expect a "blind acknowledgement of evolution". Science has never been about blindly accepting anything - that's how it's made progress over the centuries. People who are genuinely interested in evolution have the choice open to them to learn about it in a proper, well-researched way. Honestly, it's worrying that you equate a subjectivity-driven idea like "Citizen Kane is the greatest movie of all time" with belief in evolution. There is absolutely no equivalence between the two things.

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  7. [i]People who are genuinely interested in evolution have the choice open to them to learn about it in a proper, well-researched way.[/i]

    Ofcourse they do. But I do wonder how high this must be on the priority list of a Texas rancher who may have trouble with something as basic as balancing his accounts or reading newspaper editorials.

    It's interesting that America, a country reviled for its ignorant cattle belt, has been the seat of most of the cutting edge scientific and cultural progress in the past 100 years! That's because the American education system enables kids to identify what they are inherently good at, instead of drilling them with theories that they "ought" to know.

    Nassim Taleb dwells on this in his book The Black Swan which I heartily recommend. Here's an extract:

    Whenever you hear a snotty European presenting his stereotypes about Americans, he will often describe them as “unintellectual,” “uneducated,” and “poor in math,” because, unlike European schooling, American education is not based on equation drills and memorization

    Ofcourse, at no point am I drawing a parallel between religious indoctrination and biology instruction at school. It's just that I'm a conservative who believes in knowing things on a "need to know" basis. To each his own.

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  8. Honestly, it's worrying that you equate a subjectivity-driven idea like "Citizen Kane is the greatest movie of all time" with belief in evolution. There is absolutely no equivalence between the two things.

    There isn't an equivalence, except that a lot of people who subscribe to evolution do so because it is respectable to do so. Not because they have actually understood it from its first principles. To my mind, there isn't much difference between a person who is totally ignorant of evolution and a person who believes in it out of peer pressure.

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  9. Well obviously. We're told about evolution, as we are about the earth being round and gravity and what not. I doubt many people would have bothered themselves with thinking about stuff like this otherwise or indeed despite this education. The point? I dunno. That the idea of evolution is, in the minds of most people, no more the product of reason and science than the idea of we being spawned from the poop of Jesus or whatever.

    The basic thing is, in our situation - by which I mean relatively "well educated" English-speaking middle class India (leave aside the quibbles with such a generalization) - everyone "knows" evolution. It is the accepted thing.

    Why does the lack of knowledge of evolution bother you? Is it that you fear we will find ourselves in the minority and at the mercy of religious nuts? How much is just basic discomfort about the fact that the knowledge of this "fact" of the world is not universal?

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  10. Why does the lack of knowledge of evolution bother you? Is it that you fear we will find ourselves in the minority and at the mercy of religious nuts?

    Bozo: nothing to fear - we already are in the minority and at the mercy of religious nuts.

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  11. And interesting that you mention being spawned from the "poop of Jesus", considering that this book is about people who believed flies and other vermin were spontaneously spawned from poop and other wholesome material. (To paraphrase old Willie, "As flies to wanton boys are we to the gods, they poop on us for their sport.")

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  12. http://armariummagnus.blogspot.com/2009/10/gods-philosophers-how-medieval-world.html

    Belated comment. But I had to post this link as it is quite relevant to the discussion we had earlier. I'm no expert on the topic. But this post appears to hint that there cannot possibly be a consensus on the extent to which Christianity hindered the progress of science in the Middle ages.

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