When I was in High school, there were four kingdoms: Plant, animal, single celled Eukaryotes, and prokaryotes. I remember at the time not being able to get an answer for where fungi belonged.
For Kingdoms to have any meaning, you want organisms within a kingdom to be more closely related to each other than to organisms from a different kingdom. If you want to divide plants from animals, you’re forced into at least five Kingdoms, and if you don’t want fungi to be animals, you need six.
From an article I saved from January, 1996, prokaryotes and Eukaryotes divided 2 Billion years ago. From an animal-centric point of view, archebacteria split off 1.7 billion years ago, algae split off 1.23 billion years ago, plants 1.0 billion years ago, and fungi 965 million years ago.
I believe these divisions match up with Louie’s six kingdoms, with my prokaryotes his protoctista, and my algae his eubacteria.
They sure do look like atypical plants, and that’s how they were classified for decades. They aren’t mobile, and they reproduce by spores or by offshoots from the parent body. Based mainly on their reproductive habits, my old high school biology textbook placed the fungi on the developmental line between algae and mosses.
But now with genetic techniques organisms can be compared directly at the DNA level, and it turns out that fungi aren’t really plants at all. As far as multi-cellular organisms go, the division seems to be:
Plants: Make their own food using chlorophyl
Fungi: Digest whatever food is lying around
Animals: Go out hunting for food.
Corresponds to types of stars. (O, B, A, F, G, K, M) Os are blue-white supergiants, Gs are main sequence stars (like the Sun) and Ms are red dwarfs. (R, N and S are for some odd type stars that don’t fit the normal classifications.)
“Sometimes I think the web is just a big plot to keep people like me away from normal society.” — Dilbert
[Standard Disclaimer for all discussions involving categorization]
Categories are things we invent to assist our thinking. They don’t exist in nature. We impose them.
[/disclaimer]
This is particularly true for biological taxa. We can’t even define a species with any precision, much less “higher” categories. Definitions which “definitely” include all members and exclude all non-members are extremely rare. We create categories according to what’s useful for present purposes. So it’s not remarkable that the categorization will change from time to time.
George Lakoff provides a lengthy discussion of categories in his book Women, Fire, and Dangerous Things: What Categories Reveal about the Mind, including phenetics vs. cladistics criteria mentioned above.
One of my favorite quotes from the book:
“I used to think the brain was the most important organ in the body, until I realized who was telling me that.”
Emo Phillips
“He says that fungi are plants, but have no chlorophyll and reproduce by sending out spores. Hence, they’re put into their own family.”
Now I know you said this is oversimplified, but where does that leave ferns? They reproduce by sending out spores but are green and therefore have clorophyll (sp).
Thanks, TANSTAAFL. Ah, my heady days as a stripling amateur astronomer… wish I were back in the boonies so I could get a good look at the sky once more.
louie: read my message again and see which mnemonic I was asking about.
All I wanna do is to thank you, even though I don’t know who you are…
