Spontaneous Generation sounds like the Myth of the Flat Earth. Something cute to believe in for people who need to feel superior to the “primitives” of earlier times.
Did anyone really believe in it? I am having a hard time believing that people who spent their whole lives in an agricultural setting would not take for obvious that cows come from cows and mice from mice.
Wiki mentions some ancient philosophers wanking to it but makes no mention of popular belief.
So, some light on this matter?
Nobody thought that all life forms such as cows were produced by spontaneous generation from non-living matter: as you note, they had plenty of evidence to the contrary.
What they did think was that some forms of life were produced spontaneously from non-living matter, or could be made to do so.
And yes, such theories were popularly believed by uneducated people and children until well into the past century, and probably to the present day. Ever read Booth Tarkington’s Penrod Jashber?
Yup folks, this really was a widespread folk belief.
Isn’t belief in spontaneous generation required in order to explain the origin of evolution? That is, to explain how the first life occurred.
Live birth may be blindingly obvious in cows, but there are a lot of creatures that would have confused people.
Flies, for instance. Food would spoil, dead things would rot, and suddenly there’d be maggots all over the place. Unless you have a really close-up view of momma fly laying eggs or something, “maggots come from rancid meat” is as good an explanation as any.
Eels were another mystery. All European eels spawn in the Sargasso Sea, a place notable for not having pre-modern marine biologists ogling at eel orgies. As the Wiki page recounts, it took until the 1700’s for someone to find the gonads in the eel he was dissecting. It wasn’t until almost the twentieth century that they figured out that those little transparent things they sometimes found in the ocean were baby eels.
The one that baffles me is that Aristotle apparently thought that bears were born as shapeless blobs, and that their mothers licked them into bear-shape. You’d think that one of the supposedly greatest thinkers of human history would realize that bears are enough like humans and domesticated animals that they’d be born pre-shaped, just like we are.
Wikipedia:
So when did doubts emerge?
No.
Spontaneous generation was believed right into the mid nineteenth century. Pouchet had amassed a large amount of evidence seemingly confirming the spontaneous generation of putrefying elements. The matter of spontaneous generation still wasn’t solved by Pasteur’s experiments, as Pouchet had significant objections to them that required Pasteur to e.g. climb up a glacier and repeat his experiments.
It wasn’t a crank theory. It was solid science at the time.
Read the start of this chapter for more details (in fact, just get the book, it’s fascinating).
Further to M.I.S’s point about flies and meat, I could see how the “hair into snakes” belief could come about.
I can imagine that horse hair could contain the eggs of various parasites, which when placed in water could hatch into little wriggly things… from a child’s view they would indeed look like “snakes”.
In my opinion, the whole “Hair into snakes (or worms)” meme probably came from nematomorpha worms.
http://en.wikipedia.org/wiki/Nematomorpha
These are insect parasites (think “Alien”). They develop in the insect, when its time to emerge, they manipulate the insect to go to water, where they then emerge and kill the host. I can think of scenarios where someone put a hair in a jar of water, which attracted an infected cricket leading to a hair-like worm swimming in there.
You’ve obviously never had a fruit fly infestation in your house. After a few of those, you’ll be questioning whether we truly really are right and there is no spontaneous generation.
The spontaneous generation of microbes was debated for some time after they were discovered, until Lazzaro Spallanzani put the question to rest. The story is told vividly in Paul de Kruif’s Microbe Hunters (Chapter 2). Spallanzini devised some very clever experiments that proved microbial life didn’t arise out of nothing, refuting some important scientists of the time.
The Rabbis of the Talmud certainly believed in spontaneous generation of certain small creatures. They thought head lice spontaneously generated from sweat and ruled that one is allowed to kill lice on the Sabbath because they aren’t “real” creatures born of parent creatures.
Exactly - if I didn’t know damned well where baby fruit flies come from I’d be sure bananas turn into 'em.
Matter of fact, if a person isn’t TOLD that pregnancy can be the result of sexual intercourse, it would be difficult to know exactly what was the cause of that swelling and growth of a child inside a woman. Certainly, the cause and effect are far enough apart in time to hide the direct relationship. And since people have lots of intercourse without having children, the correlation is not perfect, anyway. It’s hard to forget what you know, but to someone who isn’t told these things, discovering them isn’t all that automatic.
My life is a never ending experiment of this. Puerto Rico, kids, bananas, mangoes, bug screens, fruit flies everywhere. Now that mango season is getting into high gear, I set up a table outside just for fruit so we can live inside.
This is the kind of thing that kills me. I can see how someone would believe that some obscure animal reproduced differently from the known ones, but mice and bears? All mammals are similar enough that I cannot imagine someone not extrapolating what they know from sheep and cows to all the rest of their furry creatures.
Read T.H. White’s* The Bestiary. It’s a translation of a medieval bestiary, with modern annotations. The annotations are some of the most interesting parts, because they explain where many of the odd beliefs may have originated. In the case of this “myth”, as White points out, bears do extensively lick their newborns, which are born tiny and – if you can’t get really close to see (not surprising with a mama bear) – apparently shapeless, so the idea of “licking them into shape” sorta makes sense (and doesn’t mean, as modern English would seem to imply, spanking a kid until he stops being bad). It’s news to me that this originated with Aristotle – most of the “facts” in the Bestiaries originate with Greek or Latin works, many of which still exist, but i wasn’t aware of this one. Also note that many works ascribed to Aristotle are now acknowledged to not really be by him, but are using his name to gain extra prestige.
As for people believing in Spontaneous Generation – they certainly did. One thing I found striking about relatively late supporters of the idea is that they did perform careful laboratory experiments, with controls and comparisons, just like we were taught in school, yet they still got results that supported SG. Yet such experimentation, we were taught, was supposed to reveal the truth. Evidently something that looks like the Scoientific Method can lead you astray if you aren’t sufficiently careful in your preparation, or are too committed to your beliefs.
Here’s one of the weirder accounts of what is often taken to be SG from a 19th century journal:
http://borderlandresearch.com/crosse.html
Apparently Crosse himself believed it was due to contamination, though (according to the Wikipedia articlem, at least). And the last link notes that another researcher replicating the work, while beinhg careful to avoid contamination, got the same results.
*Yes, the same guy that wrote The Once and Future King and The Book of Merlin. He as really interested in medieval life. Surprising, huh?
I don’t know how much people extrapolated from biological classifications before the theory of Evolution became well-established. But it seems to me that unless one believes species evolve, one doesn’t have much of a reason to extrapolate (for example) from a thing’s hairyness to a thing’s giving live birth. The only reason I know I can make that extrapolation is the fact that I know that all the hairy things have a common ancestor, and have traits that tend to be preserved over time, changing only very slowly and incrementally. So if hairyness is correlated with live birth in a few cases, and all the hairy things have a common ancestor, I’ve got a reason to think that all the hairy things give live birth. (And I’d be wrong strictly speaking–witness the Platypus–but I’d be mostly right and the inference is basically sound as long as its conclusion isn’t taken too dogmatically.)
But if I don’t have an idea about evolution and how it occured, I’m not sure why I’d think I could make extrapolations like this.
Perhaps pre-evolution biologists did make such extrapolations, but I don’t know what their justification was.
They were only trying to categorize what they actually observed. They didn’t see the mice setting up hous, mating, or giving birth. Just one day… mice.
And while their conclusions were not accurate, it seems to me their observations were. If you put out some cloth to burrow in and a store of wheat in a place where mice are common (a barn, say, or a dirt floored rural cottage), I guarantee you will “spontaneously” have mice in a short time.