Robots Reveal Insights into Evolution

September 16, 2009 By Lisa Zyga feature
(A) The robot used for the experiments, which has floor sensors to distinguish food and poison sources, and a ring of blue lights. (B) Robots emitting blue light near a food source. Image copyright: Sara Mitri, et al.

( -- In an ironic twist to our understanding of life, robots may offer a greater degree of realism for studying some of the intricacies of natural selection and evolution than real organisms offer. In a recent study, scientists have used evolutionary robots to investigate the evolution of social information. Their results mirror theoretical predictions more closely than results from experiments with real organisms, and may provide an explanation for some of the observed variation in animal species.

“Evolving robots can result in important insights for , in particular for understanding the of ,” Sara Mitri of the Ecole Polytechnique Fédérale de Lausanne in Switzerland told

In their study, Mitri and coauthors Dario Floreano, also of the Ecole Polytechnique Fédérale de Lausanne, and Laurent Keller of the University of Lausanne, will publish their results in an upcoming issue of the Proceedings of the National Academy of Sciences. The researchers experimented with computer simulations of populations of 1,000 robots that mimic the dynamic properties of real robots.

In the game-like scenario, the robots competed with each other to find a food source that emitted red light and avoid a poison. Robots received one point for every unit of time spent in the vicinity of food, and lost a point per unit of time spent near poison. Once a robot had located the food, it could stay near the food for the remainder of the game to accumulate as many points as possible. The robots also had the ability to emit blue light, and could sense light emitted by other robots.

As the researchers explained, each robot had 33 genes that were initially set to random values, so that the behavior of the robots was random in the first generation. The genes controlled characteristics such as how the robots processed sensory information and produced motor actions, such as emitting flashes of light.

Once robots evolved the ability to find food and stay nearby, their increased density near the food source also caused an increased density of flashing blue lights near the food, providing a source of information for other robots. After about nine generations, the robots became significantly attracted to blue light, resulting in even more robots crowding around the food. In response to this crowding, the robots began to be selected to decrease their own rate of blue light emission.

However, blue light emission never completely decreased to zero, even after 500 generations of evolving robots. As the researchers explained, this somewhat surprising result can be explained by the reduced selection pressure on light emission reduction. As light emission decreased, it became less informative to other robots, and less of a liability to the robots emitting the light.

“Evolutionary processes do not necessarily lead to ‘optimal’ solutions (in this case, a complete suppression of information) but consist of a complex interplay of selection pressure and variation,” Mitri said.

One important consequence of the reduced selection pressure on light emission is that, at equilibrium, there was a large amount of variation in both the production of and response to light among the robots. While most robots exhibited only a low attraction to blue light and rarely or never emitted light near food, a significant number of robots was still highly attracted (or even negatively attracted) to light, and some still emitted a lot of light near the food. The researchers speculate that complete suppression of light might never be achieved, since a reduction in this information will simultaneously reduce selection pressure on information reduction.

In general, this result means that, as selection pressure decreases on a trait, phenotypic diversity of that trait increases. This finding agrees with previous studies that have found higher than expected variation in populations’ signaling strategies; for instance, the great degree of coloration in moths has so far eluded explanation. Perhaps, as the experiments suggest, these moth populations have experienced a decrease in selection pressure on their coloring.

As the researchers conclude, evolutionary robotic systems like the one here may provide insight into understanding evolution and due to their implicit, inadvertent behaviors, such as emitting and sensing light while foraging. The experimental results here are also more in line with theoretical predictions than other empirical studies, supporting the view that more controlled experiments are needed in studies with real organisms.

“Because we can watch how robots evolve over many generations, we can formulate hypotheses and predictions regarding evolutionary systems in nature,” Mitri said. “These predictions can then be used to inspire biologists working with the real animals by providing them with potential explanations for what they observe. We do not claim that our robots are the same as any animals, but we suggest what biologists may want to test next to answer their questions.”

More information: Sara Mitri, Dario Floreano, and Laurent Keller. “The evolution of information suppression in communicating robots with conflicting interests.” Proceedings of the National Academy of Sciences. To be published.

Copyright 2009
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of

Explore further: Robots attend nursery school

Related Stories

Robots attend nursery school

June 23, 2005

Two robots are attending a nursery school at the University of California San Diego so they can learn to play well with the group.

Robots That Act Like Rats

February 15, 2005

Robots that act like rat pups can tell us something about the behavior of both, according to UC Davis researchers. Sanjay Joshi, assistant professor of mechanical and aeronautical engineering, and associate professor of ...

Lessons to be learned from society of robots

April 23, 2007

An Exeter political philosopher is embarking on an exciting project researching an artificial society of robots. As part of a team of academics from six universities, Robin Durie will be looking at how ‘artificial culture’ ...

Androids might soon become science fact

May 9, 2006

New Zealand and European scientists say it's time to send R2-D2 back to science fiction land -- and get ready to greet androids that think and act like humans.

Recommended for you

Volumetric 3-D printing builds on need for speed

December 11, 2017

While additive manufacturing (AM), commonly known as 3-D printing, is enabling engineers and scientists to build parts in configurations and designs never before possible, the impact of the technology has been limited by ...

Tech titans ramp up tools to win over children

December 10, 2017

From smartphone messaging tailored for tikes to computers for classrooms, technology titans are weaving their way into childhoods to form lifelong bonds, raising hackles of advocacy groups.


Adjust slider to filter visible comments by rank

Display comments: newest first

2.5 / 5 (2) Sep 16, 2009
This article should be titled "Robots Reveal Insights into Adaptation" because unless the term "evolution" is being used VERY loosely, this experiment does not show evolution. The robots are still 100% of what they were when the experiment started; all that changed is the relative proportions of genes being expressed. All of the genes were already present in each robot. No previously nonexistent genes were generated as a result of the experiment. For example, no robot evolved the ability to make sounds instead of flashing lights. If such occurred, that would be an example of what evolutionists claim has happened in nature.
Sep 16, 2009
This comment has been removed by a moderator.
4 / 5 (1) Sep 16, 2009
LariAnn: You have a good point, but it is a bit overstated. Feathers were likely used initially by dinosaurs for warmth and show; they were not initially used for flight. The essential genes for flight were present, but no flight. Similarly, imagine that the blue lights above were initially used for show, but were later repurposed for communication.
3.5 / 5 (2) Sep 16, 2009
On top of that LariAnn you're saying that the robots didn't evolve. Isn't that rather obvious. Metal and circuit boards do not evolve. It would have to be something like lights changing since that's what the machines can do. If there's no speaker on the robot, it won't be able to produce audio, ever. It sounds like you don't agree with evolution. That belief is fine with me (although I don't agree); but you need to admit that robots CAN'T physically evolve, so don't use that as a way of explaining flaws with evolutionary theory.
1 / 5 (1) Sep 16, 2009

Your points are well taken, and of course I am aware of the fact that the robots didn't evolve. My point is that, precisely because the robots can't physically evolve, the use of the term "evolution" and "evolutionary" to describe what happened in the experiment is entirely inappropriate and not representative of what the experiment actually demonstrated.
not rated yet Sep 16, 2009
Royale, I think given enough time, it COULD assemble a speaker... perhaps it would disassemble another robot and refashion the parts to serve it. Clearly this is not happening, but to say that a robot could not EVER develop speaker function simply because it was not built with a speaker is a fundamentaly flawed logic, since it is possible for it to learn how sound is replicated and fabricate a speaker to modify itself ( if there was some evolutionary asdvantage to do so) , it could pass down a gene that eventually learn how to bastardize itself for the speaker parts.. i dont know ...I think it is tough to say that anything is impossible anymore...anyways.. its just a matter of time beore we become full time servents of the machine. We will wish we had not been so smart and lazy.
5 / 5 (1) Sep 16, 2009 robot evolved the ability to make sounds instead of flashing lights. If such occurred, that would be an example of what evolutionists claim has happened in nature.

While I don't disagree with your statement that robots can't evolve (obviously), that doesn't mean that they can't give insight into the mechanism of evolution (which is all this title states), a result of which is adaptation. Frankly I have a bigger problem with it being a computer simulation of robots than their paring of evolution with said simulated robots.

Plus, I'm really curious about your use of "claim". You say that as if evolution isn't a logical, demonstrable mechanism.
1 / 5 (2) Sep 16, 2009
I wonder about the parameters of the experiment. For instance -is the food supply limited? Do the robots reproduce sexually, as in exchange genetic material? If so, it would then make sense to determine what pressure these factors would exert on blue light emission in terms of attracting potential mates or misleading potential rivals in order to maximise resources. Nothing like this is made clear in the results of the experiment.
not rated yet Sep 16, 2009

In order to address your comment, I need your definition of "evolution". Otherwise, you could be describing apples and I could be describing oranges. By my definition,"claim" is the right word for me to have used, but I'm almost positive that my definition of "evolution" is not the same as yours. For example, if I understand you correctly, the "logical, demonstrable mechanism" you mention is something I would not use the word "evolution" to describe.
5 / 5 (1) Sep 17, 2009
This is a strange experiment - why take the time to build robots and then play around with 'real' food. This exact experiment could be done solely via computer simulations, using multiple cyber-bots, cyber-gense, emitting variable light, looking for cyber-food and avoiding cyber-poison. In fact, many of the more sophisticated games today use precisely this kind of technology.

Using real food/poison in this way just doesn't make sense - I suppose there is some proximity to reality which they're looking for, but Occam's razor might well be applied here, and successfully at that.
Sep 17, 2009
This comment has been removed by a moderator.
not rated yet Sep 17, 2009
Perhaps this is a evolution of sorts, dependent on the interaction between two species.

If the performance of robot species feeds the imagination (and knowledge) of the human assistants, then the humans feed the robots with energy and through the process of iterative development cause the creation of the future generations of robots until such a time as the robots are developed sufficiently to feed themselves and create their next generation without the current necessity of the human assistants.

However, just like the 'blue flashing light' that does not get switched off completely, the symbiotic relationship between the human and robot species maintains as long as the benefits of the relationship outweigh any risk.

In the future the scientists may be studying why the humans are doing what the robots want them to do, just as today they study why humans do what their pets (particularly cats) want them to do.

Why is it that Earth's first explorers on other planets are robots?
not rated yet Sep 17, 2009
"In an ironic twist to our understanding of life, robots may offer a greater degree of realism for studying some of the intricacies of natural selection and evolution than real organisms offer"

I hate to say it, but is that not akin to creationists saying that the bible may offer a greater degree of realism than real organisms offer? Nothing is realer than the real thing, and its clearly erroneous to ever say so.
not rated yet Sep 17, 2009
This article should be titled "Robots Reveal Insights into Adaptation" because unless the term "evolution" is being used VERY loosely, this experiment does not show evolution.

It wasn't used loosely and it is correct. Evolutionary processes resulted in adaptation. That the genes were there at the start does not change that. The genes changed over time to alter to robots behavior. Evolution is not limited to biological processes.

not rated yet Sep 17, 2009
LariAnn, I should have been a bit more specific. I do see what you mean and I agree to the extent of robots not evolving.

KingWigid, Although I won't discount the fact that in the future robots building themselves a "speaker" may be (probably will be) possible, the fact is this: it's not evolution. If you went to a doctors office, without the doctor there, turned on a laser, and gave yourself eye surgery (assuming you had the skill), would you call that evolution? I sure wouldn't. Caliban had an excellent point by bringing up that evolution involves an exchange of genetic material. (On the flip side, maybe we can consider evolution an exchange of information. This way maybe in the future it will work...) Perhaps this can get you thinking about what is/will be possible. And by my word "EVER", i was talking about this particular robot. You can't take the robot from the experiment and have him do anything like that. He'll just eventually rust out. Not procreate, not pass on information.
not rated yet Sep 17, 2009
I need your definition of "evolution".

My definition would be that of evolution as found in biology; the mechanism through which a segment of a group of interbreeding biotic organisms is made more likely to successfully reproduce through it's genetics (phenotype, etc.), given a change in external factors (environment), which leads to a divergence of that segment's offspring from the "original" interbreeding group's genetics (phenotype, etc.) and eventual speciation.
The divergence of a segment of a group of interbreeding biotic organism's genetics (phenotype, etc.), into two distinct genetics (pheontype, etc.) and eventual speciation after generations of offspring, due to genetic mutation.

I think that should roughly cover it.

Is this a definition which you see as a falsifiable claim?
not rated yet Sep 17, 2009

Thanks for the clarification; both definitions are falsifiable, IMHO, so are good scientific definitions. Of course, one catch in both of them require knowing what a "species" is, since obviously one must know what a species is in order to determine if speciation has taken place. My point in bringing that up is because in biology, this is known as the "species problem". At this time there are a number of definitions of species, which for someone who used to think that a species was a clearly definable unit, is a little disturbing. I've always thought that if two organisms that are morphologically similar can interbreed and yield offspring nearly identical to themselves, then they are of the same species. If their offspring are of many different morphologies, then the parents are not species, but hybrids. But apparently this is not a cut and dried definition, and debate remains on this subject. Since Darwin's seminal work was 'The Origin of Species' . . .
not rated yet Sep 18, 2009
Royale, I'm cracking up at the thought of seeing myself doing my own laser eye surgery... also picturing one of these little blue light emitting space coasters holding a broken piece of speaker in each hand going ""
not rated yet Sep 18, 2009
I've always thought that if two organisms that are morphologically similar can interbreed and yield offspring nearly identical to themselves, then they are of the same species.

Generally a species is defined as organisms that can AND DO interbreed with each other. If they can but don't they are considered a separate species. I am not thrilled with that myself. I prefer a strictly genetic decision of an ability to interbreed with viable offspring. If mules were viable almost all the time I would consider horses and donkeys the same species for instance despite the strong differences between them.

As for morphologically similar I think dogs take that right out. Chihuahuas and Irish Wolfhounds do not strike me as morphologically similar.

In any case it is not that hard to come up with a working definition of species. Unless you just don't want one.

Any debate on this subject is mostly splitting hares vs rabbits.

not rated yet Sep 18, 2009
Your point is well taken. However since it is evolution we are falsifying here, the thrust of your argument is then that evolution is not affirmable (falsifiable) as species is not affirmable (falsifiable)?

I disagree. Certainly a species is always two organisms which can produce viable (fertile) offspring. I'm not aware of any case in which two organisms are labeled of the same species but cannot successfully reproduce (note that it does not matter that there are separate species which can produce viable offspring, the absolution of species is not what we are affirming).

So, can we not at least affirm that evolution is A mechanism of speciation? Speciation here being the process through which two organism's developmental reproduction results in the cessation of viable reproduction.

Interestingly this validates your original post well. What the robots did was not even close to our agreeable definition (if it is agreeable).
Sep 19, 2009
This comment has been removed by a moderator.
Sep 20, 2009
This comment has been removed by a moderator.
not rated yet Sep 22, 2009
While I think the experiment does a good job of illustrating natural selection/adaptation it does nothing to explain how the bots got there. I understand that that was not the point, but I think it should be mentioned. To have that type of setup to demonstrate/examine evolution without explaining what they evolved from and instead studying the process with everything already there ... that sounds a lot like what a creationist would do to study adaptation (but not evolution). I also agree with LariAnn - there is no new information, simply a recombination of what was there to begin with.

Just my 2 cents
not rated yet Sep 24, 2009
this experiment does not show evolution. The robots are still 100% of what they were when the experiment started; all that changed is the relative proportions of genes being expressed... No previously nonexistent genes were generated

LariAnn: evolution does not necessarily require the creation of new genes. In fact, such mutations usually lead to a quick death. Evolution more often occurs through gradual "drifts" in gene frequencies or expression (such as you're seeing with these robots). Recall that humans and chimps share almost all genes in common, with gene expression/frequency accounting for most of the morphological differences.
not rated yet Sep 26, 2009
If they were put outside in the rain the ones who just sat by the food would die faster than ones which occasionally moved around jerkily and shed the water while heating the motors used for movement.
not rated yet Sep 29, 2009
There has so far been an assumption that evolution is a process of selection of variations within a sexually varied genome, which is not at all true. Those who have made this assumption are anthropomorphizing their view of nature. Even in the mammals that dominate this view, we have various epigenetic, but heritable traits. We all inherit the ribosomes of our cells from our mothers or whichever mother provided the egg that was fertilized. It would be possible to aspirate those from an egg, produce normal fertilization, and add in ribosomes from the male or possiblym even a third individual, but that will not happen in nature.

The robots have the equivalent of asexual reproduction, with probably much more short term variation than is normally found in such. They also have an environment which has a set of rules, which is what all reproducing species have. The only difference is that the robots have a much more restricted and controllable environment.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.