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First Mechanical Gear Found in a Living Creature

popularmechanics.com

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Re: First Mechanical Gear Found in a Living Creature

#51

Post by BrandonY »

jberryman wrote: post #48

Can someone explain what this means? I don't get it: > Most other bugs synchronize the quick jolt of their leaping legs through friction, using bumpy or grippy surfaces to press the top of their legs together

I don't know much about biology, but I imagine that if your legs were very lightweight and bumpy, and you pressed them firmly against each other, they would probably stick together pretty well, and so if you tried to move them both in the same direction, but with differing amounts of force, they'd probably stay together and therefore press down in sync.

Re: First Mechanical Gear Found in a Living Creature

#52

Post by astrodust »

igravious wrote: post #6
teddyh wrote: post #2

This gives us four possibilities: 1. This geared creature must be considered part mechanical. A cyborg, if you will. 2. A "gear" is no longer (and was never) a "mechanical" device, but instead an organic one. Using gears is no longer (and was maybe never) doing mechanics. 3. Whether something is mechanical or organic depends on the process which created it. This is the "colored bits" or "patent" view. (If I build som…

5. All dichotomies are false dichotomies. 6. Creatures like this shake my faith in evolution.

Do airplanes shake your "faith" in gravity?

Re: First Mechanical Gear Found in a Living Creature

#54

Post by astrodust »

crusso wrote: post #41
igravious wrote: post #6

Earlier quoted context omitted.

5. All dichotomies are false dichotomies. 6. Creatures like this shake my faith in evolution.

6. Creatures like this shake my faith in evolution. Why? It's easy to imagine a couple of touching pieces in the ancestor of the issid that aided in synchronizing the jumping mechanics. Over time, mutations in those touching pieces interlocked more firmly until they resembled what we think of as gears. There was pressure on those mutations to proceed toward gears since the gear mechanism is a potentially successful o…

Exactly. A single bump on each leg might convey a slight advantage, and then the creature that gets two pairs of bumps that mesh together would be even better off. From there it's just a matter of time before creatures with multiple bumps emerge.

Being able to jump quicker than your less-able siblings could convey a huge evolutionary advantage. This quickly weeds out the less-able and strongly encourages this kind of structure to develop once the process has started for whatever reason.

Re: First Mechanical Gear Found in a Living Creature

#56

Post by niels_olson »

jonnathanson wrote: post #28
teddyh wrote: post #2

This gives us four possibilities: 1. This geared creature must be considered part mechanical. A cyborg, if you will. 2. A "gear" is no longer (and was never) a "mechanical" device, but instead an organic one. Using gears is no longer (and was maybe never) doing mechanics. 3. Whether something is mechanical or organic depends on the process which created it. This is the "colored bits" or "patent" view. (If I build som…

There's never been a dichotomy between organic and mechanical. All things that move are mechanical. 'Mechanical' simply refers to motion. 'Organic' is a similarly blurry categorization. The terms you're looking for are 'natural' and 'artificial,' as in "of nature" and "of artifice (created by man)." These are natural gears, which are so surprising because we'd long assumed the gear itself to be an artificial concept.…

> All things that move are mechanical.

How is that blurry?

> 'Organic' is a similarly blurry category

I thought "organic" was restricted to carbon chemistry. Seems pretty specific to me.

> The terms you're looking for are 'natural' and 'artificial,'

It may be that his choice of words conflicts with his meaning, or at least conflicts with your interpretation of his meaning, but doesn't make his original word choices less specific in their inherent meaning.

> 'mechanical' has increasingly taken on a connotation of artifice or man-make

Maybe I'm too far down the rabbit hole, but the Industrial Revolution hadn't even occured to me. There is plenty of mechanical action in the human body, and those have certainly been solids long before Latin came around.

Re: First Mechanical Gear Found in a Living Creature

#57

Post by dekhn »

pygy_ wrote: post #40
dekhn wrote: post #34

I'm pretty sure that the bacterial flagellum is effectively a mechanical gear: http://en.wikipedia.org/wiki/Rotating_locomotion_in_living_s...

No, it converts the proton concentration gradient into mechanical energy. The ATP synthase also works that way. The ADP and Pi are mechanically squeezed against each other in order to create the covalent bound. See the last two videos of [0] for the general process. The first three focus on details. [0] http://www.mrc-mbu.cam.ac.uk/category/slideshows/atpmovies

"ADP and Pi are mechanically squeezed against each other in order to create the covalent bond."

I have a PhD in Biophysics. If I ever said "ADP and Pi were squeezed together", I'd have been laughed out of journal club. The fine details of the reaction coordinate are still being argued about.

I'll grant you there are no canonical gears as a mechanical engineer would recognize them. I wasn't talking about the motive coupling. But a number of the physical structures (proteins) that couple the anchoring to the moving body have gear like properties. These are used to orient and clock the moving body in its cycle.

OK, I'll up it a notch since you guys are being picky. There are motor proteins which use ATP hydrolysis to do directed (non-random) motion. One of the plausible (IIRC it's passe now) mechanisms involved coupling the ATP hydrolysis free energy to a physical ratchet-like mechanism which, while didn't physically look like a gear when you looked at static crystal structures, seemed to behave like one using various subtle time-resolved mechanisms.

Re: First Mechanical Gear Found in a Living Creature

#58

Post by hcarvalhoalves »

cma wrote: post #22
teddyh wrote: post #2

This gives us four possibilities: 1. This geared creature must be considered part mechanical. A cyborg, if you will. 2. A "gear" is no longer (and was never) a "mechanical" device, but instead an organic one. Using gears is no longer (and was maybe never) doing mechanics. 3. Whether something is mechanical or organic depends on the process which created it. This is the "colored bits" or "patent" view. (If I build som…

An electric motor, complete with stators, etc. has been known for a while and it didn't change our concept of 'mechanical': http://www.arn.org/docs/mm/flag_dithani.gif

What is this?

Re: First Mechanical Gear Found in a Living Creature

#59

Post by boldfield »

crusso wrote: post #41
igravious wrote: post #6

Earlier quoted context omitted.

5. All dichotomies are false dichotomies. 6. Creatures like this shake my faith in evolution.

6. Creatures like this shake my faith in evolution. Why? It's easy to imagine a couple of touching pieces in the ancestor of the issid that aided in synchronizing the jumping mechanics. Over time, mutations in those touching pieces interlocked more firmly until they resembled what we think of as gears. There was pressure on those mutations to proceed toward gears since the gear mechanism is a potentially successful o…

It's easy to imagine a couple of touching pieces in the ancestor of the issid that aided in synchronizing the jumping mechanics.

Over time, mutations in those touching pieces interlocked more firmly until they resembled what we think of as gears.

If this were the case, would you not expect to observe these evolutionary steps in other organisms today? As noted in the article:

...there are many jumping insects like the issus... [though] most other bugs synchronize the quick jolt of their leaping legs through friction...

If there are "many jumping" insects, how does it come to be that only a single specie (that we know of, granted) that has evolved this feature, and why have we not observed others undergoing the evolutionary process that could/would yield them in others?

Re: First Mechanical Gear Found in a Living Creature

#60

Post by charlieflowers »

jere wrote: post #46

>Even stranger is that the issus doesn't keep these gears throughout its life cycle. As the adolescent insect grows, it molts half a dozen times, upgrading its exoskeleton (gears included) for larger and larger versions. Gotta catch em all.

It's kind of like getting your timing belt replaced.
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