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How Predictable Is Evolution?

samzenpus posted about 3 months ago | from the step-by-step dept.

Science 209

sciencehabit (1205606) writes "If the clock rewound, would organisms evolve the same way they did before? Humble stick insects may hold the answer to that long-running question in biology. Through studies of these bugs, whose bodies match the leaves the insects live on, researchers have found that although groups of the bug have evolved similar appearances, they achieved that mostly via different changes in their DNA. 'I think it says that repeatability of evolution is very low,' says Andrew Hendry, an evolutionary biologist at McGill University in Montreal, Canada, who was not involved with the work."

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Bah (0, Troll)

Anonymous Coward | about 3 months ago | (#47014117)

I knew you were going to ask that.

Re:Bah (3, Insightful)

sillybilly (668960) | about 3 months ago | (#47014887)

Can we get a Star Trek like movie but instead of meeting human looking weirdos in outer space, let's meet species that look really weird, yet make friends with us and we commnunicate. Like Octopuses, and Snake-people, bug-looking-people, birds with intellect, Koala bear looking chess players, etc.

Re: Bah (2)

staalmannen (1705340) | about 3 months ago | (#47015061)

not imaginative enough. Life in outer space would be less similar to us than bacteria on Earth is (so bird-like and octupus like is too "tellocentric"). Having said that, certain body plans are likely to reoccur like light sensors (eyes have developed several times independently on Earth) likely close to the proccesing unit ("brain", could also be distributed like in an octopus) and feeding organs.

Re: Bah (1)

AK Marc (707885) | about 3 months ago | (#47015101)

Anyone human-like advanced enough to locate us and travel to us would be cyborg anyway. A brain cased in a robot 1000 times more advanced than us.

Or, Iron Giant style. All that'd be left of the foreign civilization is AI war machines.

The sci-fi going for "unlike human" almost always goes to insect (Starship Troopers, Aliens), but nearly all Sci-Fi stays human-like for the purposes of depicting it on TV/screen.

Re: Bah (4, Interesting)

Artifakt (700173) | about 3 months ago | (#47015373)

There's a great book by the artist Wayne D. Barlowe, called "Expedition". it shows the life forms of a fictional planet called Darwin 4 . With dense atmosphere and low gravity, Everything evolves big, and almost nothing has anything like eyes (sonar is both popular and often very advanced). Without giving too much away for those who still haven't run across this, there are several common body plans that tend to run through whole phyla, and which don't occur on Earth, but make really good sense on Darwin 4. The underlying science is generally sound - I base this on the way various people who have read it point to this or that creature as less probable than the others, but seem to pick out different ones. This book has become my standard for SF aliens.

 

Re: Bah (1)

Anonymous Coward | about 3 months ago | (#47016035)

Right, but planets with different atmospheres intercepting different output from their local star(s) will favour the evolution of different light sensors and the features around them. We see this on Earth, with the optical pigments, crystallins, eyeball depth, gross periocular morphology, retina, and visual areas of the brain being substantially different between flightless and low-flying birds and high-flying birds, and between aves generally and terrestrial mammals, between land and marine mammals, between land and air animals and fish, between fish who occupy salt and fresh water and water with very different turbidity, and between vertebrates and invertebrates.

Something grossly recognizable as "eyes" might evolve in a planet whose atmospheric and upper oceanic environments have about the same optical window as Earth's, but even Goldilocks Zone planets around stars with, say, a reddish sun, would strongly select for large changes in any population possessing terrestrial eyes if it were left to evolve there, simply because *all* terrestrial eyes would function poorly unassisted in such an environment. Visual systems evolving natively might take a wholly different route, and might not even explore something immediately recognizable as a photopsin.

The point raised in TFA is that evolution is not highly repeatable with our biology and that therefore convergent evolution is because of strong selection pressures in the environment. If another biology (or our early biology transported to another compatible but different planetary environment) were to be similarly non-repeating, then that planet's environment might select strongly for features that are enormously different from those we see in large multicellular organisms. Likewise, if we rewound our own biology and environment to the distant past and did it over again, we might end up without grasses, flowers, insects, or vertebrates rather than seeing subtle changes to only some of those.

Re:Bah (2)

dbIII (701233) | about 3 months ago | (#47015147)

Solaris (book more than movies) is IMHO just about the only popular SF that's pointed out plainly that aliens are likely to be truly alien. Most of the book is about how a vast amount of work in a century since contact did little other than reflect the views the researchers had before they even came in contact with the alien/s. Even with godlike powers the alien/s couldn't get a message through from the other direction either.
Greg Egan had another approach where a chain of cloned and increasingly altered intelligences could form a bridge to communicate with aliens.

Re:Bah (1)

Alsee (515537) | about 3 months ago | (#47016193)

Can we get a Star Trek like movie but instead of meeting human looking weirdos in outer space, let's meet species that look really weird, yet make friends with us and we commnunicate.

I can imagine a world without war, a world without hate, a world where everyone lives together in peace. I can imagine us attacking that world.

-

Re:Bah (1)

WhiteZook (3647835) | about 3 months ago | (#47016253)

And don't make them all speak English...

Repeatable as Fuck (2, Interesting)

VortexCortex (1117377) | about 3 months ago | (#47014151)

Just look at how many times Eyes have independently evolved, yet they all have the same basic components.

We put water, methane, CO2, etc. in a closed system, ran some simulated "lightning" through, and got amino acids and what not forming. Various experiments show similar (even more prominently supporting) results: Nature and physics shapes the beings that exist within it.

There are plenty of other examples of evolution coming to similar results from different ends -- Just look at the shapes of sharks and whales. Not going to further dignify this anti-intellectual ignorant rubbish. Use a damn search engine, that's what we built the web for.

Re: Repeatable as Fuck (1)

Anonymous Coward | about 3 months ago | (#47014205)

The idea of another VortexCortex in the universe scares the hell out of me.

Re:Repeatable as Fuck (5, Interesting)

Your.Master (1088569) | about 3 months ago | (#47014237)

This tells us that getting a sensor is repeatable. There are high-level design details of eyes that are divergent across species. The "blind spot" is a flaw in the eye design that is shared by all vertebrates, but cephalopods don't have it. Either it's very hard to mutate our way out of the flaw, or the flaw is by itself not important enough for the extraordinarily rare mutants who evolve their way past it to gain any ground on non-mutant populations.

It's easy to think of that as an accident of fate, and eventually such accidents are bound to build up into going a different direction in response to strong selection pressures.

I think sharks and dolphins is better than sharks and whales. That demonstrates convergent evolution -- but note that dolphins still have lungs, and sharks still have gills. They got to similar body plans but they are not fundamentally the same.

Re:Repeatable as Fuck (4, Funny)

cheater512 (783349) | about 3 months ago | (#47014603)

Many people don't actually know they have blind spots so I'd say we don't need to fix it.

Re:Repeatable as Fuck (5, Funny)

Anonymous Coward | about 3 months ago | (#47014661)

we fixed that in software a long time ago...

Re:Repeatable as Fuck (2)

NoNonAlphaCharsHere (2201864) | about 3 months ago | (#47015003)

One of the best Slashdot posts ever.

Re:Repeatable as Fuck (1)

L4t3r4lu5 (1216702) | about 3 months ago | (#47015713)

This is one of those posts that deserves +6.

An Anon Coward, too. Bravo.

Re:Repeatable as Fuck (1)

agm (467017) | about 3 months ago | (#47014841)

This tells us that getting a sensor is repeatable. There are high-level design details of eyes that are divergent across species. The "blind spot" is a flaw in the eye design that is shared by all vertebrates, but cephalopods don't have it. Either it's very hard to mutate our way out of the flaw, or the flaw is by itself not important enough for the extraordinarily rare mutants who evolve their way past it to gain any ground on non-mutant populations.

If an eye with no blind-spot somehow causes a person to be more likely to have offspring than a person with a blind-spotted eye then perhaps there would be selection pressure. Otherwise it won't make a bit of difference from an evolutionary point of view.

Re:Repeatable as Fuck (5, Insightful)

Beck_Neard (3612467) | about 3 months ago | (#47015035)

It's not that simple. Something like a blind spot can't just be evolved away. There needs to be a pathway from "has blind spot" to "doesn't have blind spot" that doesn't go through "vastly decreased eyesight" along the way. Otherwise evolution will stick with what it has, and no amount of selection pressure can cause it to change.

We're vastly suboptimal in many ways. We're not perfectly tuned machines, we're cobbled-together from evolutionary scraps, and you can see it by looking at any part of our physiology. That's precisely the thing that makes intelligent design a stupid idea. Yet, we "work", and are capable of survival, and that's enough.

Re:Repeatable as Fuck (1)

tsa (15680) | about 3 months ago | (#47015085)

There are people who say that each organism is 'perfectly adapted' to its environment. I never understood them because you don't even have to look hard to find out that that is not true. Besides, if they were they would be extinct as soon as their environment changed only the tiniest bit.

Re:Repeatable as Fuck (1)

Maxo-Texas (864189) | about 3 months ago | (#47015195)

There are many many species that fit in that exact category.

As soon as their environment changes in the slightest, they go extinct.

Perhaps they are end nodes of more adaptable species or perhaps they thrive by being perfectly adapted and crowd out those less perfectly adapted. But when things change, they die.

Re:Repeatable as Fuck (1)

Beck_Neard (3612467) | about 3 months ago | (#47015513)

To be fair, though, it's possible to be perfectly adapted to your environment but also well-adapted to other environments (not that any creature is). It's also possible to be only slightly adapted to your environment but even less adapted to any other environment. Indeed, it's also possible to be well-adapted to your environment and to go extinct through just pure chance, without your environment changing at all. Darwin actually talked about that in The Origin of Species. A tree might produce hundreds of thousands of seeds yet on average only around one or two of them will itself ever become a mature tree. Survival is a delicate balance and it's easy to mess it up. That's why species are now going extinct at a rapid rate. When people say, "Oh, we don't really influence the environment THAT much", they're not objectively wrong, but even a small amount of disruption can cause huge ecological catastrophe.

Re:Repeatable as Fuck (2)

Maxo-Texas (864189) | about 3 months ago | (#47015603)

absolutely.

But don't overrate us. Even without humans, most species would go extinct. Just much slower. And I mean really slowly. Humans seem equivalent to a major natural disaster like an asteroid strike.

Re:Repeatable as Fuck (2)

wonkey_monkey (2592601) | about 3 months ago | (#47015593)

There needs to be a pathway from "has blind spot" to "doesn't have blind spot" that doesn't go through "vastly decreased eyesight" along the way.

We're vastly suboptimal in many ways.

c.f. the recurrent laryngeal nerve [wikipedia.org] . 4.5m longer than it needs to be in the giraffe, but it can't "evolve" its way to a different path.

Re:Repeatable as Fuck (1)

wonkey_monkey (2592601) | about 3 months ago | (#47015595)

Not sure why I put "evolve" in quotes...

Re:Repeatable as Fuck (1)

Alsee (515537) | about 3 months ago | (#47016197)

Maybe you were infected by a stray creationist meme, chuckle.

-

Re:Repeatable as Fuck (1)

wonkey_monkey (2592601) | about 3 months ago | (#47016389)

Urgh, maybe I was. And don't call me chuckle, flower.

Re:Repeatable as Fuck (0)

AK Marc (707885) | about 3 months ago | (#47015131)

If an eye with no blind-spot somehow causes a person to be more likely to have offspring than a person with a blind-spotted eye then perhaps there would be selection pressure.

We don't know if the first human proto-eyes had a blind spot or not. It has been proposed that blind-spot gives better vision in direct sunlight, which is why the land dwellers have it, and the sea eyes (never in direct sunlight) don't have one. But you can't just invent sunglasses and get any evolutionary pressure for no blind spot.

Re:Repeatable as Fuck (2)

Sique (173459) | about 3 months ago | (#47015451)

Fishes have a blind spot too, thus the point is moot.

The blind spot appears because the light sensible cells are built in reversely. Their connection to the brain leaves the cells from the outside, e.g. from the skin side of the cells. Thus this eye needs a place where the nerval connections cross the light sensible area again to get to the brain. This place, where the nerves crosses the retina is the blind spot. This is a general flaw in all vertebrate eyes.

Re:Repeatable as Fuck (1)

AK Marc (707885) | about 3 months ago | (#47015677)

Cephalopod eyes have no blind spot. Perhaps the fish that spend more time at the surface had different evolutionary pressure (more light).

The blind spot appears because the light sensible cells are built in reversely. Their connection to the brain leaves the cells from the outside, e.g. from the skin side of the cells. Thus this eye needs a place where the nerval connections cross the light sensible area again to get to the brain. This place, where the nerves crosses the retina is the blind spot. This is a general flaw in all vertebrate eyes.

Had the eye been intelligently designed, you could run them radially out, then around the back to the brain, rather than making a blind spot. Well, that and the issue of the light blocked by the connections running in front if the sensors, a problem the Cephalopod eyes don't have.

Re:Repeatable as Fuck (2)

TheLink (130905) | about 3 months ago | (#47015705)

It's not a big flaw since it makes it easier to have and maintain the tapetum lucidum or retinal pigmented epithelium and still have relatively high resolution.

Thing is even intelligent designers can create optical stuff with flaws.

For example reflecting optical telescopes have flaws since the detector (or secondary mirror) part is in between the mirror and the target AND the detector also needs support structures. These block and distort light. https://en.wikipedia.org/wiki/... [wikipedia.org]
But most astronomers accept and cope with these flaws- quote wiki: "Nearly all large research-grade astronomical telescopes are reflectors."

FWIW I'm a Christian and I think most of the Intelligent Design believers arguments are ridiculous.

But if there's one thing in this universe that should give you pause and make you wonder, it's consciousness - the actual subjective experience itself (not talking about "free will" which is a different thing). You can have all the laws of physics explain how things move etc, but how will they ever explain this consciousness? And it's the very first "observation" all scientists ever make :).

But is this phenomena even "necessary"? Couldn't the whole universe work like it does without it existing?

I can't even prove beyond all doubt that others experience this phenomenon and are conscious. And I can't prove my consciousness to others. I just have to take it by faith that these "imaginary friends" called "you" and "I" exist.

Re:Repeatable as Fuck (1)

kbg (241421) | about 3 months ago | (#47016117)

To me consciousness is just memory and the ability to make decisions based on old memories. "Couldn't the whole universe work like it does without it existing". Yes sure it could, for simple lifeforms you really don't need consciousness, just look at plants they don't have consciousness and are just programmed with specific reactions to specific circumstances. But for complex lifeforms that need to adapt and survive in complex environments I think consciousness is a necessary trait to have to be able to react to unknown circumstances correctly.

Re:Repeatable as Fuck (1)

Anonymous Coward | about 3 months ago | (#47015441)

Yeahhh... doesn't that prove parallel evolution of high level structures will converge regardless of variety in low level structures? I.E. that organisms may not evolved in the exact same way DNA wise, but that they would end up looking and functioning incredibly similarly anyway.

Re:Repeatable as Fuck (1)

Pino Grigio (2232472) | about 3 months ago | (#47015683)

Though it might not be a flaw. As Nick Lane points out, evolution is cleverer that you are. For example, the nerves that cross the front of the retina could have evolved to act as wave guides improving vision, not making it worse compared to say, the eye of an octopus which is "correct" as you might design it.

Re:Repeatable as Fuck (2)

Anonymous Coward | about 3 months ago | (#47014249)

You misinterpret the question.

It was not "would the end results have similar function", but "would the function be achieved the same way".

It is repeatable as any random process (i.e at the detailed level it's not).

Look at your own examples. All of those eyes are different, and whales/sharks have some fundamental differences (the main propulsion being the most obvious)

Re:Repeatable as Fuck (5, Informative)

rubycodez (864176) | about 3 months ago | (#47014255)

you are silly, vast differences in eyes in the animal kingdom. the spookfish eye has a side chamber with mirrors and a second retina, and works like a reflecting telescope. The Tarsier can't even move its eyes in the sockets, has to turn its head, besides night vision can see in ultraviolet but can't see color. The collosal squid has a built-in headlight, a photophore, in each eye to illuminate what it is focusing on, the dragonfly has 30,000 eyes that can see polarization of light as well as ultraviolet let, and moreover has 3 additional eyes of another type that are hypersensitive to extremely fast movements a human can't perceive. How about four-eyed fish with eyes to see in air and another pair for water?

Re:Repeatable as Fuck (2)

gewalker (57809) | about 3 months ago | (#47014355)

Don't forget lobster eyes, very cool design - lots of square mirror boxes. They are even planning an x-ray analog of them at Nasa [nasa.gov]
And the lowly scallop has a very nice set up to about 100 reflectors 1 mm in size.

Re:Repeatable as Fuck (4, Interesting)

rubycodez (864176) | about 3 months ago | (#47014575)

also could have mentioned some bird's eyes that can see the earth's magnetic field; and goats with their horizontal rectangular pupils, which combined with the eyes position on the skull gives them a 340 degree field of vision without even having to move their eye. they can see you coming up behind them!

Re:Repeatable as Fuck (2)

Camael (1048726) | about 3 months ago | (#47014915)

I have to say as a complete layman that I find this whole discussion fascinating. I had no idea there was such a wide variety of eyes in this world.

Which makes me wonder though why we haven't actually been seeing any/many inventions making use of these principles to augment our own vision. For example, I can see that a physical analog for the goat's vision may have some application in the field of law enforcement, or vehicle HUDs or anything for that matter where a larger field of vision would be an advantage.

Re:Repeatable as Fuck (1)

dargaud (518470) | about 3 months ago | (#47016351)

Which makes me wonder though why we haven't actually been seeing any/many inventions making use of these principles to augment our own vision. For example, I can see that a physical analog for the goat's vision may have some application in the field of law enforcement, or vehicle HUDs or anything for that matter where a larger field of vision would be an advantage.

...It's called a side mirror in your car !

Re:Repeatable as Fuck (1)

tsa (15680) | about 3 months ago | (#47015087)

My rabbits have that too and they have round pupils. They can even see you coming from above.

Re:Repeatable as Fuck (1)

serviscope_minor (664417) | about 3 months ago | (#47015733)

The tarsier and 4 eye fish are remarkbaly cool, but they are variations on the vertebrate eye, which means they're much more similar even to each other than the various types of invertebrate eye. The interesting thing of course is that the various ranched all evolved eyes from very different starting points.

Also if you want awesome eyes, look at the the mantis shrimp. Hyper spectral, polarisation sensitive and capable of independent depth perception (trinocular, not binocular like us mere vertebrates) with each eye independently.

Re:Repeatable as Fuck (0)

Anonymous Coward | about 3 months ago | (#47016275)

Mantis Shrimp - 16 color cones compared to the 3 humans have.

you are silly, vast differences in eyes in the animal kingdom. the spookfish eye has a side chamber with mirrors and a second retina, and works like a reflecting telescope. The Tarsier can't even move its eyes in the sockets, has to turn its head, besides night vision can see in ultraviolet but can't see color. The collosal squid has a built-in headlight, a photophore, in each eye to illuminate what it is focusing on, the dragonfly has 30,000 eyes that can see polarization of light as well as ultraviolet let, and moreover has 3 additional eyes of another type that are hypersensitive to extremely fast movements a human can't perceive. How about four-eyed fish with eyes to see in air and another pair for water?

Re:Repeatable as Fuck (3, Insightful)

Bite The Pillow (3087109) | about 3 months ago | (#47014301)

The key question is whether the same results would come from different ends, again.

And the key evidence is that parallel evolution uses different changes from different genes to achieve the same end.

The question that I have to ask is, if different changes result in the same end, can the follow-on changes result? Or are they stopped?

Flippers turn into hands, but using different gene combinations - does that stop the thumb from differentiating? Or would evolutionary pressure still reward the mutant with the thumb?

I haven't read the whole thing, but I'm not swayed on any part of the question other than someone is now thinking about this. It is far from the foregone conclusion you think it is. In fact, in your statements, it stops at the interesting point. Will eyeballs that evolved differently be able to further evolve in similar ways? Or are they forever doomed, due to their makeup of different proteins, to be different? Or is it somewhere in the middle, which sounds plausible pending further research?

Re:Repeatable as Fuck (3, Insightful)

plover (150551) | about 3 months ago | (#47014433)

I think the answer is self-evident: alternate reality results would be just as diverse as species are today, and while they would bear superficially similar results, they would be "different animals." Commenters above have noted that vastly diverse organisms in a common environment still successfully evolve common features: they may have similar means of locomotion, means of food detection, means of sexual partner selection, and on and on, yet the specifics for any given species will be completely different from the other species.

Would the appearance of an opposable thumb on a flipper cause the lengthening of the appendage into something more useful, like an arm? Maybe, because arms are a useful advantage for food gathering; or maybe not because arms aren't as hydrodynamic as flippers. Or maybe there'd be a fork with two successful species resulting. I don't think the follow on changes would stop, they just would be different changes.

But as to the original article, why would anyone think that if we rewound the clock that a chaotic process would repeat? It's not like the universe called rand() with a common seed when it started mutating DNA.

Re:Repeatable as Fuck (2)

Chikungunya (2998457) | about 3 months ago | (#47014891)

But as to the original article, why would anyone think that if we rewound the clock that a chaotic process would repeat? It's not like the universe called rand() with a common seed when it started mutating DNA.

It's a valid question, when looking to the simplest organisms such a viruses or bacteria you can observe repetition of specific adaptations when under the same environmental pressures (up to a certain point). You neutralize several strains with monoclonal antibodies or a compound against a specific protein and the escape mutants frequently show the same changes. The question is "how much of this is conserved in more complicated organisms?" It would not be the first time that an apparently chaotic process was actually following some hidden rules.

So yes, it seems that adaptation is quite chaotic in macroscopic life, but since there was a possibility that this was not the case it has value to confirm it.

Driving analogy (1)

Camael (1048726) | about 3 months ago | (#47014985)

Forgive me for trying to boil this down into more simplistic terms to understand the concept:-

So what you're saying is that just because 2 different drivers drove from Town 1 to Town 2 (similar results), it does not necessarily mean that they took the same route. Driver A had to buy groceries, pick up his daughter, visit the video store so he drove a certain route. Driver B had to top up his gas, return a library book and buy dinner so he took a different route (evolutionary pressures). But both of them ended up in Town 2.

Would this be a reasonably accurate metaphor?

Re:Driving analogy (2)

Sique (173459) | about 3 months ago | (#47015461)

Actually no. Because both drivers had to use their respective route again if they drive again from Town 1 to Town 2. After some generations you would have two different tribes of drivers, one that drives along the grocery store and the kindergarden, the other one via the gas station and the library. And if the video store closes, some drivers of the first tribe cease to drive at all because it doesn't make sense to them anymore while the new hardware store causes other drivers of the first tribe to morph into a subtribe that drives to the hardware store instead.

Re:Repeatable as Fuck (0)

Anonymous Coward | about 3 months ago | (#47015951)

But as to the original article, why would anyone think that if we rewound the clock that a chaotic process would repeat? It's not like the universe called rand() with a common seed when it started mutating DNA.

That's part and parcel of the question in TFA. The question rephrased is: Does evolution follow some sort of deterministic function, or is it truely random?
A lot of theoretical physicists believe (yes believe, because there's not a shred of evidence to back it up) in something called determinism. The idea that once the big bang happened, everything was set into motion with specific information that is merely being decompressed-- playing out over time, into what we know as reality. If this were true, evolution would be repeatable not only into a finite set of possibilities (likely), but into a set of one possibility, regardless of any appearance of randomness.

Re:Repeatable as Fuck (2)

gmuslera (3436) | about 3 months ago | (#47014419)

Not taking into account interaction between random changes in different species. Change is random, but natural selection is not, if your random changes make you survive and breed, they may remain enough time to become evolution of your species. But if a random change in a prey (or a predator) turns into viable a random change in a predator (or viceversa) then you could get something new, same for environmental changes. Is not a butterfly effect, but is enough to not make very predictable the course of evolution.

Re:Repeatable as Fuck becuase porn is repeatable (-1)

Anonymous Coward | about 3 months ago | (#47014853)

Just look at how many times Eyes have independently evolved,

You have proof? (I mean actual not falsifable digital video proof) becayuse from my viewpoint they haven't. There were created numerous times by a single individual. I could say the same thing.

Just look at how many times Cars have independently evolved,

smh

Re:Repeatable as Fuck becuase porn is repeatable (1)

able1234au (995975) | about 3 months ago | (#47015521)

A god botherer interested in proof? That makes a change but then again you only throw out those statements since you will not read any proof

According to http://en.wikipedia.org/wiki/E... [wikipedia.org] "Complex, image-forming eyes evolved independently some 50 to 100 times"

>There were created numerous times by a single individual.

I thought your imaginary friend was a trinity? so shouldn't it be three individuals (i could never work out who the holy spook was though)

It would be different but... (0)

Anonymous Coward | about 3 months ago | (#47014173)

Some themes would very likely recur. Birds and mammals are both warm-blooded, but there last common ancestor was a long time before either were warm blooded. Male and female are likely to be the norm too as they will out compete the other sexes. Human evolution in particular really is a phenomenal collection of responses to a long string of seemingly random and dramatic environmental changes.

Re:It would be different but... (0)

Anonymous Coward | about 3 months ago | (#47014471)

This discussion is the same as "Is the mind a machine" discussion. I support the other side. I believe the mind is a machine, when it is understood that given the same exact state (memories, input, chemical balances, et cetera), the next state will always be the same.

If two universes are in the exact state, then I would expect the next step in time would result in the exact same result. Thus, no matter how many steps are taken, the results will be the same. Note that this system simply says that other timelines, or as a parallel to the mind, other reactions, will not result, not that they could not be considered in a meta sense, but that they would not occur in the first place outside of a thought experiment.

Seems somewhat predictable ... (4, Insightful)

perpenso (1613749) | about 3 months ago | (#47014227)

Convergent evolution suggests it is somewhat predictable, unrelated species having evolved similar solutions to similar problems. If a solution is clearly better nature will tend to go there given sufficient time and experimentation (mutation).

The fact that a trait may be expressed by different DNA sequences doesn't really seem to undermine this. The DNA sequences are implementation details. Evolution is about solutions and environments not DNA sequences.

Re:Seems somewhat predictable ... (2)

Anonymous Coward | about 3 months ago | (#47014287)

The fact that you have widely different 'implementation details' solving similar problems suggests that it's NOT as deterministic a process as your'e suggesting.

Nature exerts a strong evolutionary pressure on animals that can *sense the environment around them.* One good way of sensing the environment around you is a complex "camera eye" - but there are many ways of implementing this in multiple organisms, which means that minute variations in environment can have a large effect on evolutionary outcomes.

If we lived underground in permanent darkness, eyes would be irrelevant - but our hearing, smell, taste, and touch would probably be MUCH more sensitive.

Re:Seems somewhat predictable ... (1)

perpenso (1613749) | about 3 months ago | (#47014531)

Who said it is a deterministic process? Evolution is based on random mutations. All that is being suggested in that given a large number of experiments a more optimal solution tends to be found, if one exists. That similar environments can independently converge (discover) upon such a solution. Its not unlike multiple independent runs of a Monte Carlo simulation finding the same maxima.

Re:Seems somewhat predictable ... (0)

Anonymous Coward | about 3 months ago | (#47014667)

> Who said it is a deterministic process? Evolution is based on random mutations.

All chaotic systems respond to random perturbations, so the question is really moot.

"If we turned back the clock, would EVERYTHING turn out the same way it did before" is the crux of the matter. And there's no way to test it, so why ask?

Re:Seems somewhat predictable ... (2)

Tablizer (95088) | about 3 months ago | (#47015397)

One good way of sensing the environment around you is a complex "camera eye" - but there are many ways of implementing this in multiple organisms

I wonder if an insect-like compound eye is competitive at a larger scale. It seems to me it may be more damage-resistant in that it fails incrementally (spots), where-as a single-chamber design like ours can be taken out of commission if just one part fails.

Well, we do have 2 eyes such that we have 1 spare, but we lose stereo sensing if one goes out. In compound eyes, you only lose stereo in the individual damaged spots.

But I wonder if compound eyes can be good at "center focus". Tetrapod eyes can be very keen in the center of focus due to density of cells and the large lens. That may be tricky to duplicate using bunches of direction-specific cells with little independent lenses. Light waves diffract too much with small lenses if I'm not mistaking because of their size relative to the wavelength of light. It's a general rule of thumb of nature that your "antenna" should be roughly at least the size of the wavelength of the radiation (light) you are sampling.

Re:Seems somewhat predictable ... (3, Insightful)

richtopia (924742) | about 3 months ago | (#47014653)

Convergent evolution also depends on how you define two features similar. For example, the convergent evolution of oxygen carrying blood in Cephalopods could be a counter example to the prediction argument, as their blood has oxygen bind to copper.

So both bloods were evolved to perform the same task of moving oxygen, however they use two different mechanisms to perform the task.

Re:Seems somewhat predictable ... (0)

Anonymous Coward | about 3 months ago | (#47014671)

I always wondered about how insects and mammals both have legs, or insects and birds wings. Even though they did not have any of those when their spieces parted ways.

Re:Seems somewhat predictable ... (0)

Anonymous Coward | about 3 months ago | (#47015059)

Since the eye evolved independently dozens of times [nyas.org] , why not the leg?

Re:Seems somewhat predictable ... (1)

Urkki (668283) | about 3 months ago | (#47015153)

I always wondered about how insects and mammals both have legs, or insects and birds wings. Even though they did not have any of those when their spieces parted ways.

That's only because of the broad, vague meaning of "leg" and "wing". The examples you list are vastly different structurally and functionally.

Re:Seems somewhat predictable ... (0)

Anonymous Coward | about 3 months ago | (#47015301)

Molecular evolution != predictable
Evolution == somewhat predictable

Re:Seems somewhat predictable ... (1)

Sockatume (732728) | about 3 months ago | (#47016379)

I think in this situation, by "is evolution predictable" they mean "is evolution reasonably deterministic with respect to creating a given set of genetic code given a set of starting code and a certain environment".

The answer is "no".

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It depends... (5, Interesting)

radtea (464814) | about 3 months ago | (#47014243)

The degree of molecular similarity in the DNA changes to achieve a particular result will depend strongly on the type of change one is looking at.

For the case of toxin-resistance, which is much closer to the molecular level, the odds of similar changes to the DNA are much higher than for complex morphological changes.

Molecular changes like toxin-resistance are more likely to involve a single gene that codes for a single enzyme, changing the enzyme so that the toxin is no longer metabolized in a harmful way. There are going to be a very limited number of ways to do this because it's pretty close to a one-gene/one-enzyme mapping in many cases.

Morphological changes, on the other hand, involve a whole network of genes that are turned on over the course of development, and the network can be altered in many different ways to get to the same result. Think about it like a road network where you're used to taking a particular route to get from A to B. If a bridge goes out on your your usual route, you may choose different alternatives depending on time of day, the kind of vehicle you drive, etc. Networks create choices.

Even then it will depend on the kind of morphological change we are talking about.

For example, there is a lizard in Mexico, which was studied in the '80's or '90s. There were several related species living inland, and a couple of isolated species on the coast near the Yucatan peninsula. Both the coastal species had an extra cervical (neck) vertebra, and it had been assumed on the basis of this similar morphology that their evolutionary history had been a general migration to the coast, an adaptation to coastal environments that involved having a longer neck, followed by a general die-back that resulted in the two existing but separate populations.

It turns out based on their genes the two coastal species hadn't had a common ancestor for millions or tens of millions of years, and the adaptation to coastal living had happened independently but fairly recently. In this case, because certain aspects of body plan are controlled by a highly conserved and relatively simple set of genes, the additional vertebra were the result of similar sets of genetic changes.

Things like body width, which is what TFA is talking about, are a lot more complicated in their regulation, so more likely to be achieved via different genetic changes that have the same morphological outcome.

I'm going to throw in a shameless plug here because it seems relevant to the topic at hand. I've just published a hard SF novel that's premised on a what-if about the role of mathematics and law-like descriptions in evolution. If you're interested in that sort of thing you should check it out: http://www.amazon.com/Darwins-... [amazon.com]

Re:It depends... (1)

wattersa (629338) | about 3 months ago | (#47014929)

Is your book available in print form? I only see the kindle edition. Also, it would be great if you could put your email address on your profile so I don't have to reply to your comment in order to contact you :P

What? (4, Interesting)

DarwinSurvivor (1752106) | about 3 months ago | (#47014245)

If I'm reading this wrong, and I hope I am, please let me know.

...researchers have found that although groups of the bug have evolved similar appearances, they achieved that mostly via different changes in their DNA. 'I think it says that repeatability of evolution is very low...

I read this as "Stick bugs have reached similar appearances through different means thus the same change probably won't make the same result".

Is this equivalent to "People can change their appearance to include a hole in the abdomen through different means (bullets and knives). Thus shooting or stabbing people are unlikely to produce holes in people"?

It may make it more difficult to guess which DNA change caused them to look like that (without an actual DNA test), but it in no way implies that those DNA changes won't necessarily cause them to look like that.

Re:What? (2)

SillyHamster (538384) | about 3 months ago | (#47014627)

Because there are multiple paths to the same result, "selecting for the same result" is not guaranteed to follow a specific path.

That is, if evolution is driven by random mutation, where the selection of a particular path is a random result.

Re:What? (1)

DarwinSurvivor (1752106) | about 3 months ago | (#47015109)

So they are saying the path (mutations) may be different even if we got the same result. Makes much more sense.

Re:What? (0)

Anonymous Coward | about 3 months ago | (#47015845)

But they're talking about predictability and repeatability, not inferring evolutionary path from phenotype. If different paths arrive at similar adaptive solutions, this actually suggests high repeatability, but of course not in the somewhat silly sense that every mutation would happen exactly the same.

What? (2)

ianchaos (160825) | about 3 months ago | (#47014635)

Yes you are reading that wrong. What they are saying is that since you can end up with similar looking creatures that took different DNA routes to get there, it's only the results that matter and not the DNA framework.

If you can end up with the same body style with different DNA then if you rewind the clock and started over there would be no reason to believe that you would end up with the same creatures we have today.

Re:What? (2)

DarwinSurvivor (1752106) | about 3 months ago | (#47015115)

The summary was a little confusing. When they said "wound the clock back", I thought they were talking about re-implementing the same mutations and expecting a different result, not animals conforming to similar situations via different mutations.

Re:What? (4, Insightful)

Anonymous Coward | about 3 months ago | (#47014715)

no, a better example is - we handed the spec to a bunch of different developers...

They each gave us wildly different code to achieve the same goal.

If we give the same specs to other developers, we expect the same result. That the code will be wildly different each time for the same goal - so we can't predict what it will look like.

Re:What? (2)

DarwinSurvivor (1752106) | about 3 months ago | (#47015105)

Ok, I think I get it now. So they're not saying we probably wouldn't end up with animals that look like they do today, but that we would likely end up with the same looking animals with different DNA than we have now. That actually makes a lot more sense.

Very similar. (1)

dicobalt (1536225) | about 3 months ago | (#47014309)

There are humans similar to us on other Earth type planets. Dinosaurs too. Maybe even some sentient avians and aquatics?

Re:Very similar. (0)

Anonymous Coward | about 3 months ago | (#47014547)

Yeah, and their must be some planets where they evolved into a higher form of life like pure energy - why in the world a life form would evolve into pure energy in the first place and remain an individual without dispersing its energy in every which way is beyond me.

And according to Star Trek, evolution isn't for adapting to ones environment to survive, evolution is for attaining "higher forms of life".

I think every every evolutionary biologist should make it a point to punch Star Trek writers' lights out.

Re:Very similar. (1)

thunderclap (972782) | about 3 months ago | (#47014875)

Yeah, and their must be some planets where they evolved into a higher form of life like pure energy - why in the world a life form would evolve into pure energy in the first place and remain an individual without dispersing its energy in every which way is beyond me.

And according to Star Trek, evolution isn't for adapting to ones environment to survive, evolution is for attaining "higher forms of life".

I think every every evolutionary biologist should make it a point to punch Star Trek writers' lights out.

Why? Because they are wrong and you are right? How do you know that dinosaurs didn't attain "higher forms of life". You don't. Don't presume you know more than them about something that can't be proven.

Re:Very similar. (1)

Barsteward (969998) | about 3 months ago | (#47015663)

What's a "higher form of life"?

Environment shapes evolution (5, Insightful)

manu0601 (2221348) | about 3 months ago | (#47014369)

Looking at cows, dolphins and horses genetic proximity [ucsc.edu] shows unexpected results, as cows and horses are not the closer in the trio, despite their similar features.

That suggests environment drives evolution in a predictable way, while the genetic evolution is not. This is the really amazing point: evolution find similar solutions to similar problems, but it does so through different ways.

Re:Environment shapes evolution (1)

rubycodez (864176) | about 3 months ago | (#47014593)

oh? what about aquatic animals(and mammals at that!) that used to be land animals, that went back to the sea?

Re:Environment shapes evolution (1)

manu0601 (2221348) | about 3 months ago | (#47014617)

They still look very similar: environment shaped their evolution.

Re:Environment shapes evolution (0)

Anonymous Coward | about 3 months ago | (#47015799)

Whales, like dolphins, are an example of land animals that went back to the sea. It has to be said that changes in an environment are not predictable either, which any dinosaur living today would agree with.

Re:Environment shapes evolution (1)

Rashdot (845549) | about 3 months ago | (#47015761)

> That suggests environment drives evolution in a predictable way, while the genetic evolution is not.

Of course. For many generations the insects that didn't well enough resemble the plants that they lived on, they got eaten before they could reproduce. So eventually this insect will end up looking exactly like the plant to its predators.

momkind (r)evolutionary new clear options (0)

Anonymous Coward | about 3 months ago | (#47014377)

we can bet our honor & compassion restoration on these earthbound representatives of creation.... creation remains undefeated since/until forever

determinism is for cowardly philosophers... (0)

Anonymous Coward | about 3 months ago | (#47014429)

...who atheistically welcome the implied lack of design, but fear the potential for chaos. Fear not, naturalistic cowards. Indeterminism in the details within an overall environmental structure is the reality, as the biologists and physicists know.

Re:determinism is for cowardly philosophers... (1)

Anonymous Coward | about 3 months ago | (#47014921)

How do people like you even have the brain power for breathing?

Burgess Shale (2, Interesting)

Kittenman (971447) | about 3 months ago | (#47014501)

Refer to Stephen Jay Gould and his "Wonderful Life" http://en.wikipedia.org/wiki/B... [wikipedia.org] also. Gould mentions that there were a range of various paleobiological doohickeys bopping around at the same time, and we come from one group that happened to swim better, or whatever. Next time round, we'll have five eyes.

Well, I'm not explaining it right, but that's why there's books...

Insufficiently large sample (1)

mark-t (151149) | about 3 months ago | (#47014549)

We need to see how things evolved on other worlds, evolving entirely independently of the life forms on this planet, which may have in some way influenced eachother, in order to even begin to gauge how predictable evolution is.

Ig Nobel Prize (0, Flamebait)

gargleblast (683147) | about 3 months ago | (#47014583)

a lot of the changes are random

And here's me thinking that all random mutations [berkeley.edu] are random. Give these guys a Nobel Prize.

Re:Ig Nobel Prize (1)

OneAhead (1495535) | about 3 months ago | (#47014745)

Sorry sir, I'm not in charge of the Ig Nobel Prices. Tell you what, I'll give you a "contextomy of the month" price.

No Shit (0)

Anonymous Coward | about 3 months ago | (#47014905)

Genetic Drift - it's what's happening mofos.

Not Enough Information (2)

kenwd0elq (985465) | about 3 months ago | (#47014975)

We know precious little about how evolution proceeded here, and we know nothing at all about how it might have proceeded elsewhere.

We can guess that it would be carbon based, because carbon has four covalent bonds and would have been formed sooner than silicon (with 4 bonds, but lower energies) would have. Beyond that, we'd need a few dozen D20 dice to calculate the odds.

But any real scientist knows that at some point, we have to admit WE DON'T KNOW how it might turn out. Wild-assed guesses aren't science, even if some people who claim to be scientists are sometimes wild-assed guessers.

Australia and other isolated environs. (1)

jimmydevice (699057) | about 3 months ago | (#47015167)

Wrong, Duh!

Keep trying (1)

Tablizer (95088) | about 3 months ago | (#47015341)

It's mutant ninja turtles all the way down

There is no evolution. (-1)

Anonymous Coward | about 3 months ago | (#47015427)

There is no evolution. No scientific evidence exists. Just a bunch of idiotic theories that people have believed. Now that belief shapes their perception of the evidence. Watch Kent Hovinds movies.

Re:There is no evolution. (1)

Anonymous Coward | about 3 months ago | (#47015485)

Plenty of scientific evidence exists. [scientificamerican.com]

It's not our fault if you don't like it.

Re:There is no evolution. (1)

Barsteward (969998) | about 3 months ago | (#47015673)

oh dear, another deluded fool. Kent Hovinds is part of a group of complete idiots.....

Consciousness and Evolution (0)

Anonymous Coward | about 3 months ago | (#47015935)

What is really baffling about evolution is the appearance of consciousness: what sense does it make? Millions of years passed and we do not have any evidence of appearance of consciousness before our own. Is it going to desappear? What if our children become less and less intelligent and, at the end, lose consciousness? It is hard to immagine like the idea of ones own death. Is it logically impossible? Of course, there always remain the possibility of human self-destruction or destruction by a natural catastrophe in order for consciousness to be lost on Earth. Can we build self assembling rational robots able to outlive us? Does rationality make any sense?

Any ideas?

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