The biologist Lynn Margulis has, I believe, the most fascinating answer to that question. Discover Magazine:
The sense organs of vertebrates have modified cilia: The rods and cone cells of the eye have cilia, and the balance organ in the inner ear is lined with sensory cilia. You tilt your head to one side and little calcium carbonate stones in your inner ear hit the cilia. This has been known since shortly after electron microscopy came in 1963. Sensory cilia did not come from random mutations. They came by acquiring a whole genome of a symbiotic bacterium that could already sense light or motion. Specifically, I think it was a spirochete [a corkscrew-shaped bacterium] that became the cilium.
From her book Dazzle Gradually: Reflections on the Nature of Nature, which I enjoyed this weekend: “All I suggest is that we compare consciousness with spirochete microbial ecology.” Granted, her ideas on AIDS go a bit too far, but this theory of consciousness is attractive because it is so sensuous. She is even drawn to spirochete because of their sensuous/screwy movement. For her, thought is not some airy thing but another form of physical motion. Thought is to motion what time is to space: spacetime.
I’ll bet she really gets off on flagella.
“her ideas on AIDS go a bit too far, but this theory of consciousness is attractive because it is so sensuous.”
I think Einstein already rebutted that nonsensical argument: “If you are out to describe the truth, leave elegance to the tailor.”
Wow. She is six kinds of crazy.
And she is wrong…
Because two things that vaguely look alike does not mean that they are in anyway related. Spirochetes do not sense light or motion for one thing. But the real scientific error here is that she misunderstands that whereas cilia are based on a small gene set (an operon), the cellular morphology of the bacterium is based on many many genes and massive amounts of epistasis (gene interaction).
Genetic transfer simply doesn’t work this way. The expression of an absorbed gene works within its new framework. It doesn’t somehow keep a memory of the overall shape of its ancestral host organism.
This kind of prancing through the tulips, tralala bullshit ‘science’ pisses me off.
If there is any kind of connection between cilia and spirochete morphology it is convergent evolution. A mouse didn’t eat a bird once and gain wings. Bats independently evolved them because wings are awesome and take advantage of many exclusive niche environments.
@3, thank you for saving me the trouble of ranting much the same thing. Much appreciated.
@3: Yeah, what #4 said. I bet Charles thinks that rhinos and elephants are close relatives.
On that note, I should mention that bats are laurasiatherians, and mice are euarchontoglires. Bats’ closest living relatives are odd-toed ungulates, carnivorans, and pangolins.
5) actually hippos are close to whales. 3) lynn margulis has had a real impact on biological thinking. she has won some big battles. you make it sound as if she was born yesterday.
@6 – She makes herself sound like that without any help from us.
@6: HUH?
I imply that rhinos and elephants are not closely related*. You mention that hippos and whales are fairly closely related. Do you try to debate, or do you just let random facts fall out of your mouth?
And yes, I know all about whales’ origins as semiaquatic ambush predators (rather like hairy crocodiles) closely related to artiodactyls. I think I know more about cladistics than you do.
*They’re not; rhinos are laurasiatherians and elephants are afrotherians, and their outward similarities are the result of convergent evolution.
8) i was really joking. sometimes my humor comes out wrong. but thanks for the good information, i mean that.
@6 Dr. Margulis has of course made a major contribution to biology. James Watson is another giant of science, but that does not lend one iota of credibility to his racist views.
Dr. Margulis simply does not back up her model of evolution with empirical evidence, and some of her affirmations are so jaw-dropping that I worry that her mind my be failing, since they entirely below a woman of her intelligence. The idea that a spirochete can just “become” sensory cilia, or the sperm flagellum, is something I would expect from someone with a creationists level of understanding of science, not a molecular biologist.
@4 <3
@6 I would love to sit sown with you Charles and talk about evolution and especially Dawkins. You are absolutely right, Lynn made a few interesting advances in the field, but she is now trying to apply the same theories to everything in biology. You can hypothesize sure, but not if your hypothesis fly directly in the face of empiricism.
Her early theories were inspired (there was no data to back them up nor refute them). That is not the case with her current ideas.
I have seen this before in scientists. There are a few that have trouble letting discovery take the field where it will. True there are leading scientists that will influence the direction of research, but the thing about science is that the truth ALWAYS wins out.
You can suppress it, but you can never get away with falsifying it or misdirecting it for long. Regardless of your intentions. She is also allowing so bitter sexism into her arguments (male scientists don’t want to admit their sperm tails come from bacteria!?).
Firstly, injecting politics into science helps no one. Secondly, her argument is bullshit. A true scientist of either gender doesn’t give a shit if something works one way or another. The just want to know how.
@ 10 Concurrent thinking it would seem. We must BE the same person. There is no other explanation.
Oh boy, Laynn Margulis. This is another example of her taking Endosymbiotic theory much too far. She might as well believe in the aquatic ape theory. For anyone not aware of her theories she thinks that evolution hardly exists in the traditional sense. She believe that evolution mostly happens not through mutation but through interspecies exchange of genes. Needless to say there is hardly any empirical evidence for this outside of a very specific subset of microbiology.
Endosymbiotic theory needs to be considered but this is a great example of one person with an honestly revolutionary idea that tries to take it too far.
When the only tool you have is a hammer everything looks like a nail.
@12 no, I think there’s a better explanation. I think I am the product of the endosymbiosis of you and another person. How else can you explain the positively eerie resemblance of ideas? You cannot! Any attempt to refute this means you are a man with with self-conscious sperm 😉
@14 Hey, why do you get to be the final product? My sperm and I find that unfair.
@14, on the other thread you said you were a grad student. I’m a recent PhD ergo I am the final evolved product (or the exhausted unemployed, but why be picky?) because as we all know evolution is linear like that 😉
Kidding! I hope to tag-team with you on another Mudede thread soon. He’s always great fun, once the pain of slaming your face against your palm at great speeds eases.
@16 🙂 It’s a date.
As an undergrad, I guess that makes me a pretty basal form.