Fluorescent Mammals Are Much More Common Than You'd Think (theconversation.com) 30
An anonymous reader quotes a report from The Conversation: Recently, several mammals have been reported to "glow" under ultraviolet (UV) light, including our beloved platypus. But no one knew how common it was among mammals until now. Our research, published in Royal Society Open Science today, found this glow -- known as fluorescence -- is extremely common. Almost every mammal we studied showed some form of fluorescence. [...] We started with the platypus to see if we could replicate the previously reported fluorescence. We photographed preserved and frozen platypus specimens under UV light and observed a fluorescent (although rather faint) glow. [...] We repeated this process for other mammals and found clear evidence of fluorescence in the white fur, spines and even skin and nails of koalas, Tasmanian devils, short-beaked echidnas, southern hairy-nosed wombats, quendas (bandicoots), greater bilbies and even cats. Both fresh-frozen and chemically treated museum specimens were fluorescent. This meant it wasn't preservation chemicals such as borax or arsenic causing the fluorescence. So, we concluded this was a real biological phenomenon.
Using specimens from the Western Australian Museum's collection, we took the experiment to the next stage. We recorded every species of mammal that was fluorescent when we exposed the specimens to UV light. As a result, we found 125 fluorescent species of mammal, representing all known orders. Fluorescence is clearly common and widely distributed among mammals. In particular, we noticed that white and light-colored fur is fluorescent, with dark pigmentation preventing fluorescence. For example, a zebra's white stripes fluoresced while the dark stripes didn't. We then used our dataset to test if fluorescence might be more common in nocturnal species. To do this, we correlated the total area of fluorescence with ecological traits such as nocturnality, diet and locomotion. Nocturnal mammals were indeed more fluorescent, while aquatic species were less fluorescent than those that burrowed, lived in trees, or on land.
Based on our results, we think fluorescence is very common in mammals. In fact, it is likely the default status of hair unless it is heavily pigmented. This doesn't mean fluorescence has a biological function -- it may just be an artifact of the structural properties of unpigmented hair. However, we suggest florescence may be important for brightening pale-colored parts of animals that are used as visual signals. This could improve their visibility, especially in poor light -- just like the fluorescent optical brighteners that are added to white paper and clothing.
Using specimens from the Western Australian Museum's collection, we took the experiment to the next stage. We recorded every species of mammal that was fluorescent when we exposed the specimens to UV light. As a result, we found 125 fluorescent species of mammal, representing all known orders. Fluorescence is clearly common and widely distributed among mammals. In particular, we noticed that white and light-colored fur is fluorescent, with dark pigmentation preventing fluorescence. For example, a zebra's white stripes fluoresced while the dark stripes didn't. We then used our dataset to test if fluorescence might be more common in nocturnal species. To do this, we correlated the total area of fluorescence with ecological traits such as nocturnality, diet and locomotion. Nocturnal mammals were indeed more fluorescent, while aquatic species were less fluorescent than those that burrowed, lived in trees, or on land.
Based on our results, we think fluorescence is very common in mammals. In fact, it is likely the default status of hair unless it is heavily pigmented. This doesn't mean fluorescence has a biological function -- it may just be an artifact of the structural properties of unpigmented hair. However, we suggest florescence may be important for brightening pale-colored parts of animals that are used as visual signals. This could improve their visibility, especially in poor light -- just like the fluorescent optical brighteners that are added to white paper and clothing.
Whiter Than White (Score:3)
Nature discovered the "whiter than white" contribution of fluorescence to white fur and hair, added to all laundry detergents these days. If you look at house dust with UV it is always blue due to these detergent whiteners that are released in the dust as fibers breakdown.
Re:Whiter Than White (Score:4, Informative)
If you look at house dust with UV it is always blue due to these detergent whiteners that are released in the dust as fibers breakdown.
Is that still true? Wikipedia tells me "Optical brighteners have replaced bluing which was formerly used to produce the same effect."
I understood the blue dust is a pigment, Prussian Blue, aka Ferric ferrocyanide, [wikipedia.org]
and a separate thing to fluorescence. See https://en.wikipedia.org/wiki/... [wikipedia.org]
Re: (Score:2)
Yes it is true. Those "optical brighteners" are fluorescent dyes [wikipedia.org], not bluing. Bluing was replaced by the fluorescent dyes in the 1950s and early 1960s, basically 60-70 years ago. The dust isn't blue, it glows blue in fluorescent light. Without that it is a dull grey. You have probably never seen a laundry product with blueing in it in your entire life (though specialty blueing is available, you won't find it in your grocery store).
Have you never seen a "black light"? If you walk under one everything you wea
Re: (Score:2)
The dust isn't blue, it glows
nevermind, i carelessly misread your earlier post to say the dust was blue. Of course I fscking know what "black light" and white cloth is, don't be so condescending.
But why does laundry power so commonly still have blue granules in it?
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Nature discovered the "whiter than white" contribution of fluorescence to white fur and hair, added to all laundry detergents these days.
Most, not all detergents. It isn't hard to find ones without dyes if you care.
You are correct that in recent years some mass market detergents have been offered without optical brighteners - Tide Purclean for example only came on the market in 2016.
This is a surprise (Score:4, Interesting)
while aquatic species were less fluorescent than those that burrowed, lived in trees, or on land.
Fluorescence is pretty common in aquatic species. Living deep enough so that red and green light is filtered out, all that is left is blue. Things would look pretty unremarkable reflecting monochromatic blue light, so the theory is that fluorescence under blue restores the color spectrum.
Dude... (Score:4, Insightful)
What sort of experiment did they perform when discovering white things glow under a blacklight... what sort of munchies did it involve? Did they have the good LSD or just some sketchy blotter? Inquiring minds want to know.
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It could have anything on it... or nothing. That's why it's sketchy.
These days it is easier to find information but when I was a teen microdot or gels were pretty much always good shit because anyone who took the time and care to make them could manage to make clean LSD and cared about product that looked the part. Actually knowing how the world works I wouldn't be surprised if that is exactly what someone would have started selling crappy variants packaged this way and this clue is probably blown by now.
Re: (Score:1)
Is this the hippies + gerbil theory?
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No this is a case of science discovering "In particular, we noticed that white and light-colored fur is fluorescent, with dark pigmentation preventing fluorescence" when literally everyone who ever partied as a teen/young adult already knows that light and especially white things fluoresce, whether they are animal fur or anything else.
Re: (Score:2)
the study was, of course, sponsored by a pro-skin cancer advocacy group, which gets kickbacks from dermatologists . . . :)
hawk
Not surprising (Score:2)
Those around Three Mile Island have a healthy green glow.
Beloved? (Score:3)
I do not think a platypus is beloved! The only platypus I know is always ruining my inators, including my beloved firstpostinator! Curse you Marvin the Monotreme!
Re: hmm (Score:4, Informative)
Marsupials are mammals.
The order of mammals comprises three classes: marsupials, placentals, and monotremes.
Re: (Score:1)
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Yes, but you said "marsupial not mammal". No need to drag animalia into this.
I Wanna Glow (Score:3)
Will make me easier to find in the rubble.
What about (Score:2)
bleached or ageing white hair?
fluorescence may be a general tendency of life (Score:4, Informative)
Ignobel prize? (Score:2)
Lots of organic substances fluoresce (Score:2)
That's why we use UV lights in forensic examinations. If you use the right
Fluorescent fur? Try human skin! (Score:3)
"We repeated this process for other mammals and found clear evidence of fluorescence in the white fur"
Oh, I've known about this for ages. Under filtered 365nm UV light, humans exhibit three natural colors; black, white, and gold-yellow are what you will see for brown/black, grey/white, and red hair, respectively.
We also all have a unique skin pattern under UV light. You think you might only have a few freckles, but under a filtered UV light, you will see light and dark areas all over your skin. The dark areas are the ones that will get darker/de-color over time. I have observed this on myself and watched it follow what's visible under UV.