5 ms·
Fluorescent mammals are far more common than earlier thought
- londons_explore 3y agoFluorescence is one way to defend against the harmful bond-breaking abilities of UV light. I suspect in many cases it is simply the biologically cheapest 'sunblock'.
- Brometheus 3y agoWhy is it on the belly then and not on the back? Countershading?
- tejtm 3y agoMany non mammals have vision that includes UV (birds, reptiles, insects ... ) if any of these hunt the mammal, fluorescence may be a way of not reflecting light the predator can see. Fluorescence must emit a lower frequency and intensity of light than could have been reflected
- meindnoch 3y agoMost mammals have no concern for UV damage, as they're covered in fur.
- londons_explore 3y agoWhen young, the fur often hasn't grown yet. Also, the fur itself may degrade in UV, making it weaker, fading, and losing waterproofing and other properties the animal relies on. And finally, the cost of fluorescence may be very small - meaning that it may have had some benefit at some point in the past, but there now no selective pressure to get rid of it.
- foobar1962 3y agoI heard this story on the radio today. They started off with references to fire flys and other creatures that generate light (I dunno the name for that phenomenon) the led into the main story that lots of mammal fur fluoresces under UV light. Not even close to being the same thing. Bad journalism.
- flobosg 3y ago> (I dunno the name for that phenomenon) Bioluminiscence.
- dghughes 3y ago>Bad journalism. That seems harsh. Couldn't it just be a fun general discussion of how light in nature among animals is observed?
- etrautmann 3y agoNo - a TON of things naturally fluoresce when excited by external photons. The size range of proteins is great for that. Proteins that produce light through phosphorescence are a completely different thing and shouldn’t be hand waved into the same category. Some exception could be made for molecules like gfp, etc.
- zdragnar 3y agoEver watch CSI? Lots of organic fluid will fluoresce under a strong UV / blacklight. Very, very different than bioluminescence. It is mildly interesting, but the comparison is really misleading.
- RajT88 3y agoYou're confusing 2 terms: Fluorescence and Bio-Luminescence. The title as written is accurate; what's confusing is other articles sometimes conflate these two things, and so some people also mix the two terms up. Bananas fluoresce; squid bio-illuminate.
- resoluteteeth 3y ago
- flobosg 3y agoThe actual publication: https://royalsocietypublishing.org/doi/full/10.1098/rsos.230325 https://royalsocietypublishing.org/doi/full/10.1098/rsos.230...
- stared 3y agoI have learnt that platypuses glow in the UV light from, well, https://www.youtube.com/watch?v=Zxf2MgYCOm0 https://www.youtube.com/watch?v=Zxf2MgYCOm0
- daft_pink 3y agoSo this just means that they reflect uv rays not that they have some sort of glow in the dark system recharged by the sun during the day to help them see at night.
- dexwiz 3y agoBit more complex than reflection. Reflection preserves the wavelength. Fluorescence is where light is absorbed, some energy is transformed to heat/motion, and then photon is re emitted at a lower energy. In UV fluorescence the initial wavelength is invisible and the final one is visible. Technically you can visible to visible fluorescence also, but it’s less impressive to us.
- saltcured 3y agoAnd then there is multi-photon fluorescence where several low energy photons are absorbed simultaneously to pump up the electron state and then it can emit a higher energy photon! This is used in a lot of biomedical imaging with infrared illumination yielding visible wavelengths.