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Behavior May Influence Evolution
eldavojohn writes "Pending your beliefs about evolution, National Geographic is running an interesting article on the influences of behavior on evolution. The study supports the controversial idea that an animal's behavior in response to environmental change can spur evolutionary adaptations. By adding a predator to an island where a species of lizards lived with no predators, they witnessed a quick shift in the average length of legs on the lizards. Long legs meant to escape were useless against the new larger predators while short legs became the dominant feature since they increased climbing ability (to trees the predators could not reach). For the finer details on the research, visit the Losos Lab Research Page."
The study also supports a somewhat controversial idea in biology: Animals' behavior in response to environmental change can spur evolutionary adaptations.
Could that imply that the behaviour of disbelieving scientific facts could spur a reduction in brain size in order to adapt to reduced intelligence?
"We are all geniuses when we dream"
- E.M. Cioran
It only makes sense. If the "animal" is intelligent to overcome its primal instincts it can avoid "evolutionary" dangers.
Are we not doing seeing this now in humans with antibiotics? Genetic manipulation?
How many people on Slashdot have said that the gene pool has become watered down due to the protections of civilization?
Why is this article awaiting my beliefs about evolution?
When the environment changes, some animals are better adapted to the new change than others. Details at 11.
'Sensible' is a curse word.
Ok, here it goes:
It certainly explains the midget 'cause short legs help him/her climb up the mountain and trees to be closer to FSM!
does that mean that the abundance of pr0n on the 'net will make my johnson longer?
This isn't evolutionary adaptation - it's much more simple than that. If you start killing all of the lizards with long legs, the ones with short legs are going to mate and have offspring with short legs. There is nothing new or "adapted." Also, if the short-legged ones get away and the long-legged ones don't, isn't that going to inherently affect how many have long legs and how many have short, by proportion?
From the article description, I thought this experiment was going to provide evidence for Lamarkism or something. In fact, this seems an interesting, but not too-surprising finding.
Introduce a change to the environment that causes a behavioural change - is it so surprising that some members of the population are better suited to the behaviour than others?
Apropos nothing, it's pretty sad to see such a story headed with the words "Pending your beliefs about evolution" on a site such as Slashdot. Evolution is an observable fact. Evolution through natural selection is a massively successful and well supported theory.
No doubt "behaviour influencing eveloution" will be seized upon by the intelligent design brigade. Though as usual the headline is misleading. Instead of evolution on one axis (e.g. speed) it's on a combination of various abilities (running fast/hiding/climbing/fighting) plus choosing the right strategy. If the rules of the game change, e.g. a faster predator comes along, what you see is what you'd expect - those adapted for running away (as opposed to the hiders, the climbers, the smelly chemical squirters) are now at a disadvantage; they're fighting the previous war. Nothing to see here.
It's true I tell you, feller at work's next door neighbour read it in the paper.
I'm in no shape or form a scientist, but is this really an example of evolution? The long legs vs. short legs reminds of the the hiking boots vs. running shoes joke. I think this is a better example of the I-don't-have-to-outrun-the-bear-just-you school of thought.
Yeah, but somehow this is "behavior" Like the lizards with the long legs that couldn't escape chose to be eaten and therefore not reproduce. With logically stupid articles like this, is it any wonder so many people dont trust evolutionary theories?
What a bunch of claptrap! You apparently know NOTHING about natural selection. I'd be very surprised to find that Carl Sagan did indeed present such a preposterous notion. Carl Sagan was a respected scientist whereas you are...? Thought so. Go lay your pseudoscience turds on an audience that cares. Digg.com perhaps?
-"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
Slow news day... AGAIN?
Of course behavior influences evolution... What's evolution, if it's not changing as a reaction to things happening?
Maybe you can argue that it was only natural for them to seek safety in the trees but I think that this study addresses something we must face. If you believe in evolution, you have to acknowledge that it's not only random genetics but also influenced by the behaviors of the animals granted those random mutations. If the lizards had behaved differently and not gone to the trees, perhaps longer and longer legs would have been developed until they were fast enough to outrun their predators. Or perhaps the species just would have been eradicated on the island.
Controversial because it implies that species may be able to subconsciously choose which feature is 'evolved' to be the dominant factor.
If you want to apply this to human evolution (as one is naturally only concerned with their own species), then I suggest you read Guns, Germs & Steel by Jared Diamond. What I found interesting is that in some places, humans began a farming lifestyle earlier than other hunter-gatherers. It was this decision by way of discovery that led some civilizations to outpace others. In fact, the choice or 'discovery' of planting seeds and harvesting them periodically eventually led to some regions invading and 'colonizing' other regions. Can we call this evolution? Can we say that some evolution hinges on behavioral choices? I think we can, but that's why it's controversial because it has traditionally been thought that the dominant feature was only influenced by the environment--not by a choice made by the animal.
My work here is dung.
Behavior May Influence Evolution
May??? This has to be the dumbest title ever. Anyone who knows the slightest thing about evolution knows that behavior has a huge influence on how an organism evolves.
Come on Slashdot editors, if you know nothing about a subject then please don't write about it.
So by behavioral changes, is the author referring to Marcianism?
Because running up a tree is a poor example.
I'm not a biologist so please correct me if I'm wrong but I thought "behavioral evolution" (which was dominant even after Darwin until about 1900) says that as an animal lives its life, its behavior changes based on the environment and those changes are then passed on to it's children. This would explain how animals were able to adapt and evolve in the then-thought short history of the Earth.
Once Mendel was rediscovered and the gene theory came up in 1900, it was back to natural selection; It was finally determined the Earth was much older and animals will revert back to their "programmed" behavior regardless of their parents behavior during their lifetime.
Running up trees is NOT a good example of "behavioral evolution". It's just evolution. Something tries to eat me, I run up a tree and escape, and others of my species that aren't as good at running up trees are eaten.
Then the next generation comes along, most of which are a little better at climbing trees but there are still a few that aren't and are eaten. There are others that are good at climbing trees but not great, so they occasionally fall off and get eaten. Or maybe the predator gets a little better and can climb part-way up a trunk but not on limbs. So after a few hundred generations the species can jump from one tree branch to another to escape. etc.etc.
Of course behavior has a play in evolution but this is not "behavioral evolution" in the Marcian sense.
$7.95/mo, 200 GB disk, 2TBxfer, MySQL, PHP, RoR.
I've recently been "Studying" evolution in my spare time.
This is a cool experiment, but it's nothing "new" -- there's no new knowledge here. At all.
AND there's NOTHING AT ALL about "behavior may be inherited!" Where did THAT come from -- anyone?(*) All these lizards were already prone to running up trees. The ones with shorter legs did it better, and within just a few generations the average legs length of the population was shorter.
That's *basic* evolution, people. Go read a damn book!!! The submitter of this article makes me angry because I realize now the fight for education about Evolution isn't just for stupid fundamentalists. A lot of smart people don't get it either.
I highly recommend getting yourself a copy of "The Selfish Gene" by Richard Dawkins. Read all the chapter notes, too -- get the recent version, don't gt an original copy because it makes you cool. Dawkins commentary on what he wrote in the newer printings is invaluable. It's an excellent book, and it's FUN to read... seriously!
(* I mean, in this context. It's well-known that behavior is inherited -- but not learned behavior.)
I can see Carl Sagan presenting it. In a 'history of science' lecture: that was a semi-popular scientifc theory for a while. Until it was disproved.
So, if you are presenting the history of biological theory, that theory should come up...
'Sensible' is a curse word.
I read awhile back about comparing possum on an isolated island showed a much stronger genetic base that produced better litters and eventual adults versus those who lived on the mainland.
Apparently the stress put on possums on the mainland is high enough to cause genetic changes. the stress weakens the immune system and has other side effects that produced a less healthy and capable possum. One possibility that was raised is that on the mainland a good number of possum are killed by vehicles. Cars are obviously a predator that mainland possum can adapt to, or maybe there hasn't been enough time yet?
I wish I could find the exact story but all I end up with are references to NZ based studies.
\
* Winners compare their achievements to their goals, losers compare theirs to that of others.
Actually, at first, the longer-legged lizards were better survivors because they're faster runners. For the first six months of the experiment, they had an advantage.
When the anoles learned that they could better avoid the predator lizards by climbing trees, the shorter-legged lizards had a climbing advantage, and they were being selected for.
The summary only tells half of the story. The article spells it out completely. It was a behavior change on the part of the prey that caused a change in which trait was selected for. Don't blame the article. Blame the summary.
I claim first use of "Error No. 0B" - or "No. 0B error." It'll be the new ID 10T!
An experiment in natural selection on U.S. Soil: 9/11/2001
Researcher George W. Bush wanting to test his hypothesis on natural selection scheduled multiple airline hijacks to crash into various high profile targets in the U.S. What effects would this have on the population? As of 2006, it's apparent that independent, critical thinking became a liability and groupthink with pre-formed opinions by right wing talk show hosts and news media became the advantage. Whereas people pre-2001 didn't take Fox News seriously, with the disappearance and slavish adherence to the new groupthink way, a massive majority (51%) of the voting public became Red. Bush was pleased with the outcome of this experiment as it proved to him that he has the ability to decrease the intelligence of over half of the American public. For his next trick he's going to prove that black is white and the American public will slavishly believe it because if you don't, you're an islamo-fascist!
So, what would happen if you gave all the sheep ipods?
This may be a case where the journalist didn't get his facts right or understood the scientist he interviewed. The selection pressure described is obviously an external force. To call this anything else is moronic. To imply that this is evidence for behavior being a causative force in evolution is insane. It's hard to believe a scientist worth his PhD would make such a mistake, but it is very easy to believe the journalist did. The most that can be said from the reported observations is that the anole lizards variation of behavior naturally caused variation in their success rate of evading the predators, as every evolutionary biologist would expect. Where is the controversy in that?
To clarify:
A good example of phentotypic plasticity is found in ants. The different castes of ants in a hill are very different, such as workers and guards. This difference isn't found in their genes. Their genomes contain the molds for all the variations.
The eggs are treated differently, and this results in vastly different creatures coming out of the egg.
This is what the study suggests is happening, to a lesser degree, in the lizards.
The National Geographic article is wildly inaccurate.
I'm a dreamer, the world is my playpen. But hey, I'm a serious person, I can't dream all the time.
Perhaps the long legged lizards was an evolutionary dead-end once the predators were introduced.
On introduction of the predators some lizards climbed to escape and some ran. For a while the longest legged run-away lizards survived as the predators ate the slower ones first. Why chase after the quickest ones when you can eat all the slow ones first.
As the slower ones were all eaten then the longer legged ones were caught as well and eaten. Now if the predators were slightly slower or the longer legged run-away lizards were slightly faster (or even evolved quicker to get faster before the died out) then either the whole species would have evolved that way or perhaps there may have even been a divergence in the species with one path being long legged runners and short legged climbers.
But as it turned out looks like running away was an evolutionary dead-end.
This is evidence for natural selection not evolution.
I don't get what this has to do with behavior.
The biggest influence on evolution is the environment (competetors, predators, food sources, climeate, etc). What seems to happen is that genetic variation slowly (by it's nature) builds in a population over time, then the environment occasionally quickly changes (the environment can change quicker than genetics can) thus suddenly making some previously begign genetic changes beneficial and others detrimental. I believe this is the basis for the "theory" (i.e. observation) of punctuated equilibrium - animal species remain relatively stable for long periods of time then undergo periods of rapid change.
Introducing a new predator is going to immediately have an effect on the population, and will immediately shift the average genetics of the population (and therefore future generations) in the direction of being better at evading the predator, since the ones that were worse than average (at this previously theoretical, but now real, task) will now be lunch.
Sir, you do realize you are talking to yourself, right?
Perhaps you should seek professional help...
Well, Novell's behavior has influenced my use of Evolution. It's been my email client for over 3 years now, but now I'm having to adjust to Thunderbird.
"It ain't a war against drugs.it's a war against personal freedom" --Bill Hicks
on evolution :
By adding a predator to an island where a species of lizards lived with no predators
And who do you think you are, gods, to play with local evolutionary process of a isolated place ? Which idiot local government official gave you the permission to toy with the island ?
But most important of all, HOW can you muster the guts to come up in front of scientific community after breaking something irreperably while trying to observe it ?
Read radical news here
"Epigenetics is the study of epigenetic inheritance, a set of reversible heritable changes in gene function or other cell phenotype that occur without a change in DNA sequence (genotype). These changes may be induced spontaneously, in response to environmental factors, or in response to the presence of a particular allele, even if it is absent from subsequent generations."
:http://en.wikipedia.org/wiki/Epigenetics)
(Source
I think the title should have been, "Outlook on Evolution".
As an aside, those who have emphasized random mutation as the primary basis for evolutionary change are completely off base. The whole point of sex (whoa!) is to produce adaptive variation.
The author of the article has wildly misunderstood the study.
What the study is saying is: "This suggests that the results observed in the field may be the result of a phenotypic plasticity in limb growth, rather than genetic differentiation."
Phenotypic plasticity is something we find amongst other thing in ants.
The various castes of ants (workers, warriors, etc) differ from eachother quite a bit. However, their genes are the same - Their genome holds the molds for all their various forms. Through different treatment of the eggs by the queen and the workers, different parts of the genome is activated.
So the study is suggesting that these lizards have evolved this ability: To, through some mechanism still unknown, influence the leg length of their children to pick between at least two different phenotypes. One with short legs, one with longer ones.
Interesting? Sure. Changing "Evolution's Driving Force"? Definitively not.
Someone needs to introduce the author of the article to an anthill. It would blow him away.
I'm a dreamer, the world is my playpen. But hey, I'm a serious person, I can't dream all the time.
Did this experiment increase the organism's genetic information? Has there EVER been an increase in genetic information?
This seems like the Baldwin Effect which has been studied in genetic algorith and genetic programming research.
Last I checked this is exactly how evolution works. A new predator was introduced and having short legs helped the lizards escape them. It only makes sense that short legged lizards would breed more since the long legged ones got eaten. The only thing I can see this proves is that evolution can happen faster than we previously thought. Am I missing the break through here or are these scientists smoking something?
WTF?
at least as far as the evolution being affected by animal behavior. The behavior can change the environment, and hence the selective process, nothing new or surprising there. Now if it said that behavior directly caused the change (i.e. created mutations), I'd say that's controversial, but I find this is nothing especially exciting, even if it did get into science.
34486853790
Connection too slow for X forwarding? Try "ssh -CX user@host"
It's not particularly controversial
It's called the Baldwin Effect - http://en.wikipedia.org/wiki/Baldwin_effect
It's also been demonstrated in computer generated artificial life environments.
It's not that the animals wants to evolve in a particular direction.
It's simply that behavior affects the environment, and environment affects evolution.
There are some reasonably good examples on the Wikipedia page
Quatermass
"Scientists introduce a predator that eats lizards with long legs, and find the average leg length of the surviving lizards to be shorter!"
The predators ate lizards they caught regardless of their leg length. HOWEVER, those with shorter legs had an advantage for survival, and this physical character eventually became dominant IN ONE GENERATION: the whole species evolved. If this wasn't the case you'll find that the introduction of a new predator would have no effect on the birth occurrence of long vs short-legged individuals.
Based on The Fine Article, all it means is that two different natural selection pressures were at play over a very short time frame. First longer legs (increased speed) were favoured, but longer term an even better strategy was staying in trees (behaviour), which then favoured shorter legs (better tree-climbing). The relationship between the change in behaviour and evolutionary pressures is unclear, but it is not the article's apparent implication of Lamarckian evolution.
This is exactly how I thought that evolution was supposed to work. Environment changes due to new predator, species evolves to handle changed environment. Yet another routine confirmation of Darwin.
How are longer legs "behaviour"? Not that I would be surprised that behaviour has Darwinian consequences. The behaviour of reproductive mating has considerable consequences - species that stop reproducing lose the evolutionary challenge.
About as dumb an article as you get
Consciousness is an illusion caused by an excess of self consciousness.
Man. Someone forgot to take his happy pill this morning I see. Look, I'm only repeating what I saw on a legitimate science show. I didn't make this stuff up. Go look it up! The main article being featured on Slashdot goes a long way to explaining why the sheep would change colors when exposed to stimuli like those poles. Until I read it, the fact that it happened remained a mystery and Carl Sagan didn't explain it too much other than to sy that it was natural selection at work. The only possible explanation is that the sheep felt a bit out of style with their bland old white coats when confronted with the presence of new trendy striped poles. So simply by thinking that, they changed their coats. I don't know how fast this stuff works, but I've been wanting a nice Eggplant wash in my jet black hair. So I'm going to think about myself looking like that for the next few months hoping that I'll beat the clock before my next colour consultation with my stylist.
-"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
This is ridiculous. This is exactly what evolution is - and always has been - all about.
This is survival of the fittest at its most obvious. Keep in mind that the word "fittest" does not apply to the quickest or strongest, but the members of the species that are the "fittest" for the environment they live in. This only become obvious to us "short time observers" when the environment changes abruptly, as demonstrated in the article.
The lizards in question undoubtedly carried some tendencies toward both long and short legs. Chances are actually pretty good the average length of a lizards legs was somewhere in the middle of the extremes. The habits of these lizards would have kept them together for the purpose of procreation, and would have shaped the general habits of the species.
When you introduce predators that cannot climb or otherwise access prey in the trees, but are quick enough to chase down even the fastest of those on ground, it stands to reason that natural selection is going to increase the proportion of offspring to short legged lizards - or more accurately, those that carried the physical ability to effectively adapt their lives to a more arboreal style. Those that could not function at all, or as effectively in the trees would have fallen out of the gene pool, so to speak.
Behavior is not the initiator of evolution, it is merely a facilitator, and a secondary one at that. It is entirely possible that some of these lizards were climbing trees long before the predators were introduced, but probably came to the ground to mate and procreate. The introduction of predation is the external pressure that either induced or enhanced this behavior. Without the predation, these behaviors would not have become the norm, and would not have resulted in evolution.
On the other hand, it is possible that such a change could have been induced not by predation, but by a shift in food supply. Imagine that the insects the anoles fed on lived both high in the trees and low to the ground for decades, even centuries. Then, rather than the introduction of a near-ground predator, imagine that some change in the foliage virtually eliminates the prey insects habitat at the ground level. The anoles can still feed, but only if they chase their food to the trees. You see the same change in the genetic pool, but you may also see a split. This isn't instigated by a change in behavior, it's facilitated by a change in behavior that is instigated by a change in environment. Big difference. The ability to change behavior based on the environment is what allows evolutionary changes, not what causes them.
On the other hand, it is very likely that these evolutionary changes would not be possible if the species were capable of including those unable to physically adapt. Look at the Human race for instance. There are millions of people that are physically incapable of managing a harsh environment where they would be required to work physically very hard or perish. We as humans tend to see it as our responsibility to help each other for the good of the species (cloaked in some moral code or other, of course). This may hinder (some might say "degrade") the improvement of the species, but that's getting into moral issues all its own. Personally, I see this as probably the only example of behavior affecting evolution without an external force. It has allowed those with abilities toward more intellectual innovation to flourish, and often procreate. Or at least to affect the direction others' offspring take in their development. We often see people who have made outstanding advances in science reach old age without children, but they often inspire others to reach farther still. One could argue that this has shifted humanity into a behavioral evolutionary mode. One could also argue that this is a good or a bad thing, or that it will be the key to the survival or downfall of the human race.
Regardless, behavior is certainly not the instigator of evolution in lizards.
Shhh... don't tell anyone, but I think this 'eno2001' character is a little strange.
-"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
He's not bashing against evolution folks, he's saying the surviving lizards have shorter average leg length because the predator ATE them!
i sure hope loss of a sense of humor isn't another evolutionary trend among humans...
"The gene pool is stagnant, and I'm a minister of chlorine."
Don't you just love flawed analysis?
From the original article:
"But as the anoles increasingly sought safety in trees, where the bulky curly-tails could not pursue them, shorter-legged lizards were favored for their superior climbing ability."
An alternative description would be:
"But as curly-tail predation took its toll of anoles that either tended to run rather than climb, or were not well-suited to climbing trees, the anole breeding population increasingly came to consist of shorter-legged tree-climbers."
I'd be amazed if 20 minutes spent tweaking the parameters of a simple population model couldn't reproduce this so-called "controversial" effect.
I'm hijacking a higher thread since pretty much everything written below is just plain wrong.
Not the submitters' fault, they simply read the article and based what they wrote on it.
Let me explain:
The article is claiming that "Evolution's Driving Force Shifts Based on Behavior"
Go to the actual research site (linked in submission), scroll down to the end, and you will find that what they're saying is:
"... another alternative is that lizards growing in different environments grow different length legs. To test this hypothesis, we raised baby anoles on two different surfaces at the St. Louis Zoo--either on 2x4's or on narrow (1/4") dowels. At the end of three months, the lizards raised on broader surfaces had longer limbs than the lizards on narrower surfaces! This suggests that the results observed in the field may be the result of a phenotypic plasticity in limb growth, rather than genetic differentiation."
Phenotypic plasticity is a term some of you may be unfamiliar with, a good example of it is found in ants.
In any given hill, there are different castes of ants. Warriors, workers, etc. They are all quite different.
However, the differences are not genetic; they arise during development and depend on the manner of treatment of the eggs by the queen and the workers, who manipulate such factors as embryonic diet and incubation temperature. The genome of each individual contains all the instructions needed to develop into any one of several 'morphs', but only the genes that form part of one developmental program are activated.
This is what the study suggests is happening to these lizards.
They're saying there are at least two different 'morphs', one with long legs and one with short ones, in the genome of the lizards.
These are then selected between (through some so far unknown mechanism) based on the environment of the lizards.
"These findings suggest the intriguing possibility that phenotypic plasticity may play an important role in adaptive differentiation by permitting lizards to occupy different habitats; once subsequent mutations arise, these differences can then be elaborated upon by natural selection."
Now, let the ghosts of Lamarckism the article has raised from their graves go to rest.
I'm a dreamer, the world is my playpen. But hey, I'm a serious person, I can't dream all the time.
Some comments in this thread about how this doesn't imply lamarckian evolution. However, there is some _other_ evidence in support of heredity of acquired changes. See: http://www.nimr.mrc.ac.uk/millhillessays/2004/here dity/
Wow, seriously? The Slashdot crowd is usually educated enough for that statement not to be necessary.
If you read Slashdot regularly, and you don't believe in Evolution, you must have an incredible ability to compartmentalize your life.
I've been saying for years that the "random mutation" model is not sufficient to explain observed reality. To me it's self-evident that what organisms do, or try to do, or possibly even want to do, has an effect on the mutations that occur (before natural selection plays its part), and natural history cannot otherwise be reasonably explained. However, this theory would mean that we're 99% ignorant of the mechanism of evolution, and modern science strongly prefers irrational but seemingly complete solutions over rational solutions that admit of our great ignorance.
Please mod parent up. Headline and summary were incorrect.
"Watered down" has no real meaning. It is merely a sentiment that has no basis in facts. There is no way to "water down" a gene pool. You can't stop evolution by "protections of civilization." As long as individuals die and there is some differential in reproduction, evolution is happening. Sure, the evolutionary pressures and the source of mutations are changing slightly, but nothing is getting watered down.
-matthew
"THERE IS NO JUSTICE, THERE IS ONLY ME." -Death
So there's nothing new here. It's just another example of how the environment of an organism (here, the lizards) influences it's evolution.
> Pending your beliefs about evolution
You might just as well believe that the Earth is flat.
People of every religious persuasion: Evolution is a fact. Learn to live with it.
You may be overly trusting in the article writer. The writer may have deliberately misinterpreted the article so as to create a controversy, base on the study's title. The idea that behavior doesn't influence evolution would actually be a whole lot more controversial among people who understand the subject. You could post exactly the same information, put a headline to the effect that it supports 'intelligent design theory,' and watch the outraged comments pile up! What fun!
Too bad evolution isn't true.
After all, we play with the Zerg.
We are Turing O-Machines. The Oracle is out there.
There isn't a lot of information provided in the article or the project home page, but from what I can see, these experiments appear to be highly unethical. Introducing a non-native species into a pristine ecosystem just to see what happens? That is a recipe for disaster, and could very well end up destroying the ecosystem of the islands that these researchers are manipulating. I would be curious to find out if this research had to go through an ethics review like most other animal experiments or if they took advantage of local laws and simply bypassed any concerns about the long term effects of what they are doing.
STFU about slashdot bias.
It's my understanding that the changes that are occurring in the lizards aren't happening across generations but within a generation itself. In other words, one litter of 10 lizards is used in the experiment, 5 in each situation. The 5 that needed to climb had shorter legs than the 5 that didn't need to climb. Genetically there is little/no variation but physically, leg length is vastly different. What I don't understand is why this is behavioral and not environmental. People that grow up in small spaces for one reason or another would end up shorter than those that didn't. Is that because they made the choice of fitting into the small space or because while they were developing in a small space that forced them to bend over. In the latter case it's just a matter of incredibly poor posture causing poor bone structure growth. In the former it's because they chose to. Personally I'm more likely to believe that the lizards developed longer or shorter legs because of growing in trees as opposed to on the ground. If you want real proof, I'd love to see a lizard change the length of it's legs as an adult depending on situations. For instance an adult lizard that has long legs, a predator shows up and it's legs shorten, then the predator dies off and the legs return to normal size (all in the course of it's adult life). THAT would be much better proof than this, but the closest I've seen to this is molting/fur loss. I'd also like to know if this change carries over, would the offspring of the short legged variant be inclined to have short legs when in normal circumstances (and grow the longer legs if the need arised) or would they return to their regular size. If it doesn't carry over in anyway then it's more akin to choosing to be a cop instead of a fire fighter rather than a step in evolution.
You seem to imply that because your argument over a sub-subject may hold some water (it does not as the other users have already shown you), the whole house of cards falls down.
That is just not true, science does not work that way. There is no archilles heel vulnerabilty that you can expose and then every scientist says: ok we pack it in. That is the mechanism of religion: you have to believe it because it is in the holy book, and everything that is in the holy book is true. Once something turns out not to be true, then the whole books comes in a different light.
You might try accepting that man wrote the holy books, and man created the religions around it, and man created the god(s).
I have created my own that I call My Invisible Friend that watches over me at night. During the day he keeps himself fit by kicking the crap out of your invisible friend/god/dog.
This space is intentionally staring blankly at you
...if the Flying Spaghetti Monster is using his noodly appendage to design lizards with longer legs, the noodle gets longer?
I'm so confused how this stuff works now.
-Styopa
That one's easy: It's turtles all the way down.
Man, you really need that seminar!
The example in the post is pure "survival of the fittest" (i.e. not eaten because you can climb a tree faster.) and has nothing to do with behaviour at all.
Honestly, it's no wonder almost 40 percent of Americans do not believe in Evolution, when they are constantly presented with BAD INFORMATION.
How many escape pods are there? "NONE,SIR!" You counted them? "TWICE, SIR!"
Long legs meant to escape were useless against the new larger predators while short legs became the dominant feature since they increased climbing ability (to trees the predators could not reach).
This could simply be the animals with long legs being eaten at a more frequent rate, so the short legged lizards are the ones surviving and reproducing. This is, at best, micro-evolution. Their genetic makeup isn't changing to accomidate the need for short legs (like evolution would *know* that it needed short legs). Its selective breeding.
-- If we don't stand up for our rights, now, there will be no right to stand up for them later.
So why waste all that money on genetic research if you can influence DNA with changes in the environment (behavior)?
Running with Linux for over 20 years!
Sorry, I gave my last Dr. Kevorkian gift certificate to my mother in law.
Lets start here, it is unbelievable that this comment was not one the first posts in here! This isnt the first time the obvious is missed before a story get burried in comments.
Like, what else is new? shooting my foot may hurt my foot? Throwing my television from the 4th floor will break it? Punching a police officer may get me in trouble?
On the other hand, this isnt actually the statement the article makes. The article says it actually helps drive evolution for a large part, rather then just be another influence. Hmmm, nothing new there either, is there, why do we have peacocks anyway?
Yet another great literary work of art from Mrs. Keller. This one belongs right up there next to, "Life is either a daring adventure or nothing. Security does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than exposure."
Hmm, I don't think "pending" means what the author and some other posters seem to think it does. What exactly is pending here? Hint: the word "awaiting" is a synonym for "pending." I don't get it.
Currently hooked on AMP
I've already maintained that there is more at work in evolution than purely DNA. An animal ( or plant ) is more than it's genetic makeup. For example it's mind and chemical states are direct descendants of it's parents - in particular it's mother - the process is one of continuous emergence. This process allows much more than DNA to be passed on. Of course locating the exact mechanisms by which this occurs is not easy - especially for armchair specialists such as myself ( programmer ) - but this by no means detracts from the theory.
What's more, consider the 98% or so 'junk' DNA that scientists are so eager to sweep under the carpet. What if each individual were a genetic experiment, and the results were stored in 'junk' DNA, which could then guide the gene activation in future generations? Or the current individual?
The Darwinian revelation was quite an important one, granted, but it is far from complete.
an animal's behavior in response to environmental change can spur evolutionary adaptations.
Growing up near all that oil made him spontaneously evolve into "a slick"
You can tell on your posts, you know. When you're feeling self-righteous and you know your post is adding to the conversation, you end it with 'kfg.' But when you're just another troll, another flamer or putting on an ugly face to make fun of someone, your initials are nowhere to be found at the end of your posts. Like Nixon's autograph diminished towards the end of his term?
While there are anciliary elements of behavior in the National Geographic article . . . the dominant factor in this research IMO is to reinforce the notion of "punctuated equilibrium". The introduction of the predators affected the entire eco-system of the islands just as the crash of the comet 65,000,000 years ago into the Yucatan affected the Earth's entire eco-system. I wonder what Stephen Gould and Louis Alvarez feel about this?
In the case of bacteria, this has been demonstrated. Some strains of E. Coli can augment their level of enzyme responsible of mutations when harsher condition are encountered.
Although this is not litteral "producing offspring that are better at resisting the environnement" (like you suggest with your "selecting warrior children") but more "making more mutation and hoping that a solution will come out of it" (a possible analogy is suddenly starting to produce children that are widely different from parent and hoping one of them will be a warrior or anything else that will help).
Even though, this is a nice blow against creationists who object that evolution is something too complexe to come out of random mutations : mutations aren't purely random. Evolution has come up with methods to optimize the efficiency of its mutations.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
Is it Lamarkism?
It's both - it's Lamagicalism!
Only three things are certain; death, taxes, and apocryphal quotations - Ben Franklin.