Some proteins like ATP synthase kind of act like gears as well: http://www.mrc-mbu.cam.ac.uk/sites/default/files/images/imag...
First Mechanical Gear Found in a Living Creature
181–190 of 191 posts
Re: First Mechanical Gear Found in a Living Creature
#182> In 2 milliseconds it has bulleted skyward, accelerating at nearly 400 g's—a rate more than 20 times what a human body can withstand. This is entirely incorrect. 9g is the limit that someone can stay conscious, but the body can withstand a lot more. Experimental subject John Stapp withstood 46.2 g. http://en.wikipedia.org/w/index.php?title=G-force#Horizontal...
Not to mention that the survivable g's are not scale invariant. At the size of an insect it would be easy to survive 400 g's, but at I mile tall, one g would probably kill us.
Re: First Mechanical Gear Found in a Living Creature
#183"They're rather specialized, and there are lots of other jumpers that don't have them, so there must be some kind of advantage." Not necessarily. Evolution has a lot to do with path dependence and in no way guarantees the best of all possible adaptations.
Isn't this the advantage?: > Larger animals, whether kangaroos or NBA players, rely on their nervous system to keep their legs in sync when pushing off to jump—using a constant loop of adjustment and feedback. But for the issus, their legs outpace their nervous system. By the time the insect has sent a signal from its legs to its brain and back again, roughly 5 or 6 milliseconds, the launch has long since happened. I…
Did you read the whole article? The article clearly states that the same thing can be accomplished using friction instead of gears (as it is in a bunch of organisms and the adult version of this organism).
Re: First Mechanical Gear Found in a Living Creature
#184Earlier quoted context omitted.
Isn't this the advantage?: > Larger animals, whether kangaroos or NBA players, rely on their nervous system to keep their legs in sync when pushing off to jump—using a constant loop of adjustment and feedback. But for the issus, their legs outpace their nervous system. By the time the insect has sent a signal from its legs to its brain and back again, roughly 5 or 6 milliseconds, the launch has long since happened. I…
Did you read the whole article? The article clearly states that the same thing can be accomplished using friction instead of gears (as it is in a bunch of organisms and the adult version of this organism).
No, I actually skimmed through it, hence my (genuine) question. Anyway, thanks for the answer.
Re: First Mechanical Gear Found in a Living Creature
#185It is for beauty like this that I believe all living things were originally designed by some intelligence, somewhere. Perhaps designed to mutate and evolve, or perhaps that was a limitation in the source materials, but there are some beautifully engineered living systems on our planet.
Just because something looks "engineered", doesn't mean it is. A perfect example is the eye. An organ of great complexity, but one that is very easily explained by logical evaluation, as well as existing living creatures and fossils: http://www.youtube.com/watch?v=Nwew5gHoh3E If you're a software engineer, I hope you understand how procedural systems and algorithms can transform data and functions. Similar processes…
As a software engineer, when I see an algorithm that transforms and processes data using instructions and symbols, I reasonably assume that someone created that algorithm.
When I'm told the algorithm is really just a random collection of instructions, assembled through an unguided process, that just happens to be work...that strains belief. But even accepting that, I'm still left with instructions, language, symbols, and interpretation. And these can only be produced by intelligence.
Something as simple as the characters we use to write code means nothing unless meaning is ascribed to them, and meaning can't arise from a strictly meaningless process (evolution, chemical interactions, etc). I think the simpler, and truer explanation for why these systems appear engineered, is because they are.
Re: First Mechanical Gear Found in a Living Creature
#186Earlier quoted context omitted.
Top comment is pretty much, "this changes my whole theory of nonsense which I just invented." It's a pseudoscientific strawman and I can't believe it was upvoted. As a mechanical engineer I see tons of mechanical components in the human body. Diaphragm pumps, ball and socket joints, pinned joints, tensile supports. None of this makes you a cyborg. https://en.wikipedia.org/wiki/Not_even_wrong
> As a mechanical engineer I see tons of mechanical components in the human body. Diaphragm pumps, ball and socket joints, pinned joints, tensile supports. The chemical engineer points at the vast complexity of enzyme catalysed reactions and intricate supply chains of nutrients. The electrical engineer observes the networked structure of the nervous system, the myriad signal processing pipelines built all from simila…
Evolved creatures are a strange mix of clever hacks and design-by-committe horrors.
http://threepanelsoul.com/2010/07/05/on-design-by-committee/
Re: First Mechanical Gear Found in a Living Creature
#187Earlier quoted context omitted.
Isn't this the same as #4?
Top comment is pretty much, "this changes my whole theory of nonsense which I just invented." It's a pseudoscientific strawman and I can't believe it was upvoted. As a mechanical engineer I see tons of mechanical components in the human body. Diaphragm pumps, ball and socket joints, pinned joints, tensile supports. None of this makes you a cyborg. https://en.wikipedia.org/wiki/Not_even_wrong
I did not invent the nonsense, it was implied by the existence of the article itself. If this flea had used some hitherto unknown chemical reaction, there would have been no article. But use a toothed gear-like structure instead, and suddenly it's an article and a post to HN, no less. This implies that it's something special with gears, which I tried to assume in my comment. I tried to present the inherent contradiction in assuming that gears are special by arguing from the reluctant viewpoint of someone who thinks it is true.
Many commenters seemed to think I was asking a question of which of the possibilities was the correct one, and (correctly) answered that the fourth one was correct. This was not my intent, I merely wanted people to reflect on the possibilities and come to their own conclusion.
Re: First Mechanical Gear Found in a Living Creature
#188This is misleading. It looks like a gear, but they are just evolved nodules that caused friction that helped the bug escape predators better. We call it a gear but it is just a mix of physics, life, and death.
If this isn't a gear, then what is a gear ?
Re: First Mechanical Gear Found in a Living Creature
#189Earlier quoted context omitted.
Awesome post. About the "fantastic two-gene change": can't there ever be a force pushing for a species to obtain two independent mutations more or less simultaneously? What I mean by that is pressure on a species to maintain / promote a few existing mutations in the population (each individual may carry one, or the other, or none, but the offspring of carriers is likely to end up with more than one). I imagine in ver…
I wanted to keep it simple. All the details do get complicated, beyond even my comprehension (beyond anybody's, as far as I know, genetic science continues to find surprising things on a regular basis). Another semi-sort-of exception is bacteria, which can for instance trade large chunks of genes directly, though, again, not in a very directed manner. There's also quite a few "control" genes that exist where it may b…
I don't remember too much from my college genetics, but I recall that since so much of our DNA isn't actively used it can evolve much further away than would otherwise be possible if every base pair was actively used. As soon as the proper start and stop codons are mutated back in (I'm simplifying), bam, you have a new active gene which could result in much more drastic change than any single mutation would provide.
Re: First Mechanical Gear Found in a Living Creature
#190> In 2 milliseconds it has bulleted skyward, accelerating at nearly 400 g's—a rate more than 20 times what a human body can withstand. This is entirely incorrect. 9g is the limit that someone can stay conscious, but the body can withstand a lot more. Experimental subject John Stapp withstood 46.2 g. http://en.wikipedia.org/w/index.php?title=G-force#Horizontal...
I think it depends on the direction of the acceleration. The John Stapp experiment was horizontal acceleration, right? Right above that: "... if g-forces are not quickly reduced, death can occur. Resistance to "negative" or "downward" g, which drives blood to the head, is much lower. This limit is typically in the −2 to −3 g (about −20 m/s² to −30 m/s²) range."
I used to work at NASA on space shuttle launches. My boss at the time had an old (50's? 60's?) era book that detailed the testing on what acceleration would do to a monkey.
I felt bad for the monkey. But yes, direction matters.