What Birds Know About Fractal Geometry 74
sciencehabit writes "In a new study, researchers find that a single number that describes the complexity of feather patterns on bird chests, a parameter called the fractal dimension, is linked to whether a bird has a strong immune system or is malnourished. When scientists restricted the food of red-legged partridges, the patterns on their chests had a lower fractal dimension than those sported by their well-fed colleagues. The food-restricted birds, on average, weighed 13% less than their well-fed colleagues and had weaker immune systems, which makes fractal dimension an easily recognizable sign of a potential mate's health and vitality, the researchers contend."
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Why are they starving birds? Says more about the experimenters than about fractals.
Call it what you will (Score:5, Insightful)
http://www.smithsonianmag.com/science-nature/Why-Are-Some-Feathers-Blue.html [smithsonianmag.com]
http://www.birds.cornell.edu/AllAboutBirds/studying/feathers/color/document_view [cornell.edu]
Re:Call it what you will (Score:5, Informative)
You are absolutely correct, it just so happens that the patterns formed are also fractal in nature. All fractals are described statistically with fractal dimension, a relative measure of complexity, in order to differentiate between scaling properties in different fractal patterns. Really, all this research is saying is healthier birds have more complex patterned feathers, but with a mathematical definition of what that complexity is.
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What? The world has come to this? Instead of how intelligent, strong, or attractive we are, the primary factor is socio-economic status?
Wow, I bet that realisation causes more than a few suicides.
Re:Call it what you will (Score:5, Insightful)
What? The world has come to this? Instead of how intelligent, strong, or attractive we are, the primary factor is socio-economic status?
Wow, I bet that realisation causes more than a few suicides.
At the level described in TFA(malnutrition leading to visible differences in development persisting into maturity) or similar(doesn't sound like they tested it; but parasite load and certain sorts of environmental pressures probably have the same effect) there really isn't a terribly strong separation of physical factors and socio-economic status(to the degree that birds have that). At the knife-edge-of-subsistence level, the fact that intelligence, strength, and attractiveness are paid for in calories and nutrient distributions really tightens the connection between personal virtues and economic status.
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Welcome to the human race. You'll find that like the majority of great apes, we are a social animal. Keeping track of your socioeconomic status is of prime importance for successfully navigating life within the tribe.
Good luck on you exciting life as a human.
~the management
PS. Don't fling poo, that's a chimp thing.
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"Keeping track of your socioeconomic status is of prime importance for successfully navigating life within the tribe."
Except there is one important statistic that contradicts this idea: people of "lower socioeconomic status" get married and breed much more often than the "upper crust".
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Comment removed (Score:5, Insightful)
Re:Call it what you will (Score:5, Funny)
"a story will come out saying men and women at nightclubs perform complex trig to find mates."
Hey , you've obviously never tried to look cool in front of some babes at a club while carrying a load of beers and having to carefully avoid all the drunks and druggies swaying about by calculating the optimal path across the dancefloor cross referenced in the time domain against the beat of the music!
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It went fairly well until I pulled out the slide rule.
Re:Call it what you will (Score:4)
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The pictures of the bird are interesting, too. No explanation for them; probably because the larger image is a portion of the smaller image scaled up in size and reversed left to right. I guess viewers are to draw their own conclusions.
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It's a detailed close up of the same bird to show the pattern. Did you think it was meant to be a different one?
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no math there but a story will come out saying men and women at nightclubs perform complex trig to find mates.
And if they decide they don't want to mate, they flip you the bird, and if they decide that they do, they flip you the mandelbird?
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A dog can estimate the direction and speed of a ball as it b
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Fuck you. This shit doesn't matter. It's a fucking bird you fucking moron. God made blue birds just like he made shitheads like you, you stupid fucking cunt.
Ugly, simple feather day again, dude?
Have a sandwich.
Re:Call it what you will (Score:5, Informative)
'Fractal dimension' seems like a cool buzzword which will make it easier to get research noticed
Well, maybe it is, but you can't actually fault them for using it. The term "fractal dimension [wikipedia.org]" is as old as the study of fractals, and is taught in university mathematics courses. It is a useful concept, as you'll see if you read the wikipedia page. It's also consistent with the traditional geometric idea of dimension.
I've only skimmed through the paper so far, but they've directly calculated the FD from its definition. The data looks pretty good. From what I've seen in the paper, I would say it's all legit.
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how did the parent get modded 5 insightful?
Because so many mods think they know what a good comment looks like, even if they have no idea of its factual accuracy.
Thanks, by the way.
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yeah, I'm pretty sure the feathers are just spread more because the bird is fatter.
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Bad title? (Score:1)
Birds know nothing about fractal geometry. It would have been extremely cool if they did.
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Indeed that would be cool, imagine the possibilities of fractal architecture in bird's nests!
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Obviously you never watched that Hitchcock movie.
Golden Mean (Score:1)
Is this related to the idea that the degree of golden proportion in the human face is a measure of beauty?
Now seriously! (Score:4, Interesting)
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But they might calculate the fractal dimension. Might see other correlated aspects of it.
Just as they perform what computer scientist have lots of trouble replicating, that is the flight, the landing, the looking around.
But all of this simply is a case of: "doesn't eat properly, looks like sh*t, doesn't get laid" phenomenon which occurs naturally in all species.
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It's a gag. The authors of the paper, and of the article about the paper, are not seriously suggesting that the birds understand fractals. The fractal dimension is just a useful descriptor for pattern complexity.
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That makes two of you.
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They weren't starved and didn't lose their feathers. They were put on a restricted (but tolerable) diet while the control group was allowed to eat as much as it wanted. (Which gets into the longstanding question of whether ad libitum-fed animals are really good control groups, given that they're pretty far from wild behavior.)
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They kept the "restricted diet" birds' food intake within the range of the free-to-eat birds in the parallel observational study. To put it another way, it'd be like finding a group of people and feeding them my shrew-like diet, but not like feeding them the diet of a dying child in a drought zone.
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You need to get the subjects' consent. If they let the birds freely choose to participate in the restricted diet, it would be okay. Give each bird subject a choice.
More Slashdot Pundit FAIL (Score:5, Insightful)
Fractals have many uses http://en.wikipedia.org/wiki/Fractal#Applications_in_technology [wikipedia.org] It is a perfectly reasonable hypothesis that birds recognize the fractal dimension of plumage in their own species. Conflating this with "being able to compute a fractal" is ignorant. Some birds are known to get information about magnetic fields through their visual channel. This does not mean they are solving Maxwell's equations.
It is possible to extract fractal dimension information from images. Typing in "fractal dimension image detection" into Google Scholar results in over 25000 references. If academics have figured out how to do this then evolution may also embody these concepts.
Posting on Slashdot is an opportunity to share knowledge and learn things. Unfortunately far to many people who post here show that they are ignorant and arrogant. I call them the Slashdot Pundits.
Just because you know one thing does not mean that things you haven't heard of are wrong. With Google and the like, it's easy to fact check. On this topic so far all we have seen is woefully uninformed people criticizing academics and making fools of themselves. I would think that shear embarrassment would tend to eliminate this kind of drivel, but I guess if you are stupid enough to make such uninformed statements, you are also incapable of understanding how bad it makes you look.
Re:More Slashdot Pundit FAIL (Score:5, Insightful)
There is, arguably, a meaningful distinction between 'knowing' something(in the sense of being able to use that something in conscious cogitation) and 'knowing' something in the sense of 'exhibiting behavior that could not be accomplished without possessing some similarly capable mechanism; but not necessarily possessing any conscious knowledge, or even consciousness at all'.
It's an open question(that the paper isn't really interested in attacking) whether birds 'know' anything about fractal dimension in the first sense, or what if anything they know at all in that sense; but there is a much stronger case to be made that they do exhibit behavior that could only be accomplished with access to the results of such a computation, even if the processing is a total black-box. Much the same is true of humans: you don't need to take physics to play catch(and, indeed, even those who have generally don't start using conscious calculation to catch falling objects); but our ability to catch objects is pretty hard to explain without positing that we have some mechanism that gives us access(and rather fast access, no less) to good approximations of answers to certain classes of physics problems.
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Wow, getting sheared and embarrassed at the same time sounds pretty harsh! Last I checked my wool coat was not thick enough yet so I'm safe for now.
Ig Nobel (Score:1)
Now, that should be worth an Ig Nobel [improbable.com], no?
Misleading title (Score:3, Informative)
why animal testing has a bad rap (Score:3)
if you are studying some awful disease, like smallpox, most people do not have a problem with purposely starving a mouse.
if you are just doing it to measure fractals, a lot of people do have a problem with it... even meat eaters.
"oh but we need basic research and that justifies it because it might save someone some day" -- yeah no it doesnt, unless you have some examples. because i can give you thousands and thousands of examples of where 'science' committed horrifying atrocities against human beings in the name of 'basic research' and used that same argument to justify it. thats the whole point - its not about 'save the animals', its about basic morality.
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While I agree with you that this skirts the boundaries of research ethics (frankly the whole field of animal behaviour research is troubling):
i can give you thousands and thousands of examples of where 'science' committed horrifying atrocities against human beings in the name of 'basic research' and used that same argument to justify it.
Dozens, yes. (Mostly in secret, and without any a priori justification by the perpetrator.) Thousands?
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Just to be clear, their protocol states that they observed a group of birds who were free to eat as much as they wanted and noted how much the different birds ate. This was a parallel study, where they just correlated food consumption to patterns with no intervention. Then for the intervention study, they fed the experimental group at the low end of that range.
Possibly a 2013 Josef Mengele Award Candidate? (Score:2)
Other applications in health and science (Score:1)
Yet another stupid title (Score:3)
Birds know nothing about fractal geometry. One does not need to know the fractal geometry of a feather pattern to deem the pattern desirable.
Another point is that they didn't prove the link between fractal dimension and desirability. It is quite possible that the prospective mate does not notice the change in plumage but looks at the overall health of the bird. Now if someone took identically healthy birds and modified some bird's plumage to change the FD and that changed the selection probability then that would be proof.