Given that Linaeus is 300 years old this week, I thought this would be a good question. I remember in Biology class during the 80’s that the teacher emphasized how artificial system of taxonomy was by presenting an unusual caterpillar. The caterpillar would bury itself in the ground and turn into a plant. Was this creature part of the animal kingdom or the plant kingdom? Both, he said, and this showed that the system was man-made and that nature did not have to follow our system.
I agree with his conclusion: taxonomy is man-made. That’s obvious. The only problem is that I can’t find any information on this elusive caterpillar. If it really existed, information should be readily available. I am coming to the conclusion that this is an urban legend spread by high school teachers.
Does anyone know where this story came from and whether or not it is true?
I completely agree with Johnny L.A. but
You knew there was a BUT coming, didn’t you?
The absolutely weirdest and most inexplicable thing I have ever seen was, while living alone in a cottage in Sweden, miles from anywhere, I went out into the garden late in the evening, around 11pm - midnight and discovered a little pile of what appeared to be insect eggs, freshly laid and sticky. I’d say the pile was the size of a golf ball and pearly white. No sign of whatever had laid them.
The following morning I went to see them again and found - fungus, thousands of strands of brown fungal growth in the approximate shape of a volcano.
They stayed there for a couple of days then disintegrated into spores and blew away in the breeze.
I didn’t take any photo’s of the eggs, much to my continuing regret, but did take a sequence of slides of the fungal growth and its dissipation, though where they are now is anyone’s guess, up in the dreaded attic with thirty years worth of accumulated junk I expect.
If anyone has anything approaching an explanation for that I’d love to hear it, it’s had me baffled for more than half my life.
Ed: the dreaded typo that only appears when you click on the ‘post’ button
The fungal growth was dry and not anything like a slime mould, if your post was in reference to mine, Revtim. It was also many discrete strands, like little tubes about 2.5" long and 1/8" in diameter. Almost as though each strand had grown from each one of the eggs.
Maybe it started with the Tibetan slime mold, but I think the teacher got his information from* Ripley’s Believe It Or Not * – not my first choice as a source of information.
Jesus. With apologies to those few who are knowledgable and competent, high school biology teachers are only second to high school physics instructors in not knowing the basics of their field of tutorage, and the best argument against teaching evolution and the theory of natural selection in biology is that they’d surely screw it up badly.
Taxonomic categories may be man-made, but that doesn’t mean that taxonomical distinctions are arbitrary or artificial; indeed, when done properly, species are categories specifically by the traits that uniquely unite or distinguish them. It’s true that not everything fits neatly into the philistine categories of “animal, vegetable, or mineral”, but that doesn’t mean that species can bridge between class or phylum. much less entire kingdoms. In the case of members of kingdom Animalia that are as complex enough to have even a rudimentary nervous system there are an enormous amount of distinctive characteristics that seperate them from other kingdoms.
It’s not that “nature doesn’t have to follow our system” but that our system inherently follows nature to the extent that we are able to understand it. When there is a disagreement between taxonomy and how species are related to each other, it’s the taxonomy that gets revised…except, of course, under the duress of abominable autocratic pseudoscience like Soviet-era Lysenkoism. Anybody who doesn’t understand this is doing a disservice by teaching a subject that they only pretend to understand.
Actually, his conclusion (if I read it right from what you’ve said) is unsound (not slightly because his example is complete bullshit).
Yes, taxonomy is a man-made system of describing things - it couldn’t be anything else unless it just fell out of the sky one day - but especially nowadays, it does actually mean something - taxonomy strives to describe phylogeny - which we certainly didn’t invent - it exists because of the ancestry of extant organisms.
So there isn’t anything that properly belongs in both the plant and animal kingdoms until you get all the way back in time to the common ancestors of animals and plants, which quite likely didn’t much resemble either.
The two-kingdom system has really been obsolete for more than 30 years. The difficulty of pigeonholing many organisms, especially unicellular ones, into “plants” and “animals” has led to systems with Five (or more) Kingdoms.
However, even a Five Kingdom system doesn’t really work if you try to apply cladistic classification. Many microrganisms are at least as different from one another as they are from multicellular Animalia and Plantae (and some unicellular organisms are closer to animals or plants than they are to other unicellular ones). To adequately categorize all this diversity at least three “Domains” (above the Kingdom level) and perhaps 20 Kingdoms would really be necessary.
I find it amusing that two of those three Domains together form one Kingdom of the old Five Kingdom system, with the third Domain encomassing everything else. And that two-Domain Kingdom wasn’t even recognized as that, under even older systems. I think this is a sign of how anthropocentric our classification schemes are and were: We’re much better at describing things which are more like ourselves.
No, it’s not arbitrary. However, there is a rather basic conflict between the Linnean system and the prevailing taxonomic philosophy at present, that is, cladistics. By its nature the Linnean system must recognize paraphyletic groups, something prohibited by cladistics.
That’s interesting. I wonder which (if any) will give way - it’s tempting to think it would be the Linnean system, however, even the divergence events that brought about the phyla must have been from (sets of) common ancestors (although not necessarily in a pattern anything like that descibed by the Linnean System at present). As far as we know, life did arise only once on this planet, didn’t it?
That was not his point: such anti-intellectualism would be inappropriate for a teacher. His point was not that the system was capricious but that it was artificial. Any system we come up with would only be a rough approximation of the rich variety of life. He did not say that the system was useless – only that it was imperfect.
Fair enough. That being the case though, he probably should have picked a better example than the plant/caterpillar thing, which isn’t one organism, but two - one a plant and one an animal - indeed the facts of that case destroy his argument.
There have been attempts to develop a non-Linnean cladisitic taxonomy, most notably the PhyloCode. However, this is rather cumbersome and is far from being generally adopted.
The Linnean system provides a convenient way for pigeonholing organisms, and since it’s been around so long virtually all museum collections and databases are organized that way. Since it would be extremely time-consuming to convert to another system, and since it is a relatively easy way to organize and retrieve information, the Linnaen system will likely be around for the foreseeable future.
Since all life on Earth shares essentially the same basic genetic code, yes.
