The Bizarre World of Living Color | Compilation

[Music] there are some amazing plants and animals out there you've got giant ones tiny ones cute ones really weird looking ones and everything in between like whatever strange characteristic you're looking for i'm sure there is a creature for you but one key feature we tend to notice about plants and animals is their color and there's plenty of weird science there too we've done a handful of episodes about coloration over the years but we wanted to finally showcase all of them in one place together so kick back relax and get ready to be amazed let's start with the superlatives because while there are all sorts of lovely colors out there some species have gone above and beyond and they are officially considered the world's most intensely colored living things i'm going to turn it over to stefan for the details the world is filled with an abundance of beautiful natural colors though some stand out more than others with super shimmery blues whiter than white whites or darker than dark blacks today we're going to talk about three of the most intensely colored living things what's really fascinating about these three is that their signature looks are all made without colorful molecules the color you see when you look at an object or a living thing is determined by the wavelengths of light it reflects back into your eyes white light like the light from the sun contains all the wavelengths we perceive as colors and when it hits something that thing absorbs some wavelengths of light and reflects others for most living things what's reflected is determined by pigments quote colorful chemical compounds that absorb certain wavelengths of light leaves are green for instance because they contain chlorophylls pigments that largely absorb all light except for green wavelengths and that's all well and good for most colors but the most intense colors we see in nature don't tend to come from pigments they come from a phenomenon called structural coloration that's when the light reflected or absorbed depends on the microscopic structure of a surface and not the absorption properties of specific molecules take the marble berry for instance it's the vivid fruit of an african herbaceous plant and back in 2012 it was heralded as the most intense natural color on the planet and it's not hard to see why these small berries which are smaller than blueberries pack a colorful punch their bright iridescent surfaces sparkle and shine in stunning blues and purples but unlike other berries marble berries don't get their color from pigments instead it comes from unique structures in the outer layers of the fruit the outermost layer called the cuticle is glossy and transparent allowing light reflected from the tissue below called the epicarp to shine through the cells in that tissue contain translucent cellulose microfibers stacked in miniature spirals these act like a series of mirrors reflecting the light back and forth between them depending on the thickness and direction of the spiral as well as the thickness of the cell's wall each cell reflects red green or blue wavelengths though most of them reflect blue light causing the berry to have a somewhat speckled but generally blue appearance below these cells is a layer of dense brown tannin pigments followed by a third layer an even deeper sheet of thin cells the tannins absorb most of the light that gets to them while the thin cells scatter what's left to enhance the purity of the color produced by the spirals in total the berries reflect 30 percent of the light that hits them and as for why the berries are such a brilliant blue well that's likely to attract berry lovers like birds in general plants that make berries are hoping animals will eat them because that means they'll carry their seeds in their guts for a while before depositing them in a hopefully distant location but marble berries don't contain lots of yummy flesh so animals have no particular reason to help the plants disperse their seeds except of course that the berries are so shiny and blue it's thought that the coloration either fools birds into thinking they're a different more nutritious species or simply looks amazing you see during courtship lots of bird species decorate their nests or other structures to prove they're a high quality mate so a shiny blueberry could bring their mating display to the next level either way the berries get dragged around helping the plant reach new areas now while the berry's 30 reflectance is impressive it's nothing compared to the brilliant 70 plus percent reflectance of the southeast asian kaipo kylis beetle their whiteness is so bright that it almost hurts to look at them and they get this super whiteness from their unique scales each is comprised of numerous tiny filaments densely packed together these fibrils are really good at scattering light and because the scattering is random all wavelengths are scattered equally making the resulting color white which is all well and good for the beetles because it lets them blend in with the white fungi that they like to live on white things are also useful to us of course which is why researchers have created an artificial white substance that mimics the structure of a kypokilis scale this substance is 20 to 30 times more white than normal white filter paper and retains this clarity of color down to a mere 10 microns thick that's thinner than a human hair now on the other hand creating the blackest black requires the exact opposite approach black is the absence of all colors so to make deep dark blacks you need something that absorbs most if not all of the wavelengths beaming at it and that's exactly what the feathers of several birds of paradise do some people who have seen these birds up close say looking at their feathers is like looking into a dark void and that's actually a pretty apt comparison because the bird's feathers reflect a mere 0.05 percent to 0.31 of the light that hits them compare that to normal blackbird feathers which reflect about three to five percent the difference in blackness comes from modifications to small branches of the feathers called barbules in most birds these are relatively flat and thin all the absorption is done by dark pigments inside the feather but in the black feathers from birds of paradise the barbules are curved dense and pocked with tiny spikes these reflect any escaping light back inwards towards the bird trapping it in the feathers until it's absorbed you might think something that deep and dark was trying to hide but that's not what these birds are after instead it's thought the super black of their feathers helps them highlight the colors of the rest of their plumage which they used during courtship to woo a mate which is why nothing but the blackest black would do though there are lots of ways to make beautiful colors it seems like when nature wants something really intense light absorbing compounds just don't cut it those feathers are outrageously dark and plenty of other birds have amazing super saturated coloration too just look at a parrot or like half the birds you'd find in a rainforest in fact lots of animals come in a rainbow of colors except for one pretty significant group mammals we come in only a few more neutral colors so why did us mammals miss out on all the fun here's one from olivia nature is full of color birds beetles fish flowers and more come in every color of the rainbow but mammals not so much we and our fuzzy relatives don't tend to have the vivid colors of other animals think of a tiger or a calico cat most of the time that's about as vibrant as it gets the evolutionary reason for mammals subdued coloration is more complex than you might think and it takes us all the way back to the age of dinosaurs most of the colors you see in plants and animals come from molecules called pigments which absorb certain wavelengths of light and reflect back others these are stored in their skin feathers fur or scales to produce all kinds of bright reds pinks yellows and more us mammals tend to be less colorful than say birds lizards or insects in part because we don't have the same range of pigments they do most mammals can only make one category of pigments called melanin melanin comes in two forms eumelanin which can produce black or brown coloration and pheomelanin which produces yellow or reddish brown colors different amounts of melanin in different parts of the body can create a variety of patterns from the black and white stripes of zebras to the brownish and yellowish spots of giraffes as for other pigments we don't really have the genes to make them but mammals can be more colorful mandrels are a type of monkey that exhibits striking blue and red coloration on their faces and also around their genitals the red comes from blood vessels showing through the skin and the blue is a result of structural coloration in which the skin scatters and reflects light in such a way that blue wavelengths are directed back at your eyes in fact most blues you see in animals are structural colors and lots of animals don't even make their pigments themselves flamingos for example pick up their pink from their diet and there doesn't really seem to be any specific reason mammals haven't evolved to do something similar which leads to a conundrum of sorts we know mammals have the capacity to be more colorful but they usually aren't so why not the most likely explanation is that mandrels birds and butterflies all share an ability that most mammals don't have they have excellent color vision you see inside your eyes are specialized cells called cone cells which grant you the power of color vision many fish reptiles and birds have four types of cone cells each with light receptors tuned to a different wavelength of light seeing all these different wavelengths together creates a complex multicolored picture but most mammals only have two types of cones making them dichromatic and since their cone cells can only pick up two main wavelengths of light they miss out on a lot of color information usually these cones are tuned to the green and blue end of the spectrum leaving them less able to clearly discern reds and yellows in human terms they're partially colorblind primates are an exception to this most primates including ourselves are trichromatic with three types of cones for seeing reds greens and blues since primates can see a variety of colors it makes much more sense for them to use bright colors for communication there's less point in flashing fancy colors if other members of your species can't see them even with our fancy third set of cones though our color vision isn't as good as many of the non-mammals in the world if you're feeling a bit cheated try blaming the dinosaurs during the mesozoic era roughly 250 to 66 million years ago the world was ruled by reptiles but there were mammals back then too and although they were mostly small and scarce compared to today they were pretty successful in a variety of niches around the world with dinosaurs dominating most land ecosystems mammals needed to find strategies to avoid competing with them and being nocturnal could have been a great tactic it's hypothesized that many mesozoic dinosaurs were active during the day so only coming out at night would have been a way for early mammals to avoid either competing with them for food or becoming lunch themselves this has become known as the nocturnal bottleneck hypothesis in evolution a bottleneck occurs when a population's genetic diversity becomes reduced in this case as a result of adapting to life in the dark in studying the genomes of modern mammals scientists have determined that not only do we have reduced vision we also tend to be missing certain genes that protect our skin and eyes from damaging uv radiation color vision and uv protection are both really helpful if you spend a lot of time in the sun but less important if you're active at night in this case all or most mammals are thought to have lost these daytime traits during the mesozoic so scientists suspect our mammalian ancestors may have spent most of the mesozoic in the dark then when the dinosaurs rain ended and mammals finally got their time in the sun they were working with limited genetic tools for adapting to daylight some of the genes that enabled daytime activities had been selected out and were long gone so even though many mammals are active in the daytime now their dna is still sort of stuck in nighttime mode only certain mammals like primates have separately evolved more complex color vision and with it more colors on their bodies our mammal eyes may never be able to see colors as vivid and varied as birds eyes can see but that's a trade-off that allowed our ancestors to survive living alongside their ancestors fortunately we humans can always add a splash of color with a favorite sweater well i guess surviving is a pretty good reason to come in boring colors especially when you realize that some animals come in bright colors for some kind of horrible reasons take early pulleys or pill bugs they're usually dark gray but sometimes they come in a lovely vivid blue which sounds really nice and beautiful until you learn what causes that here's michael with the details you might call them wood lice pill bugs potato bugs or roly-polies but they aren't lice or bugs they're not even insects they're terrestrial isopods the only fully land-dwelling crustaceans and they come in all sorts of colors there's brown light brown black every once in a while though you might get lucky and find a brilliant blue roly-poly crawling around in the dirt but your good luck is their bad luck because that blue comes from a virus and when it makes them colorful like that the virus is almost always lethal the viruses that turn roly-polies into rolly blueys are part of a larger family known as eritoviruses erytoviruses can infect all sorts of ectotherms animals whose body heat primarily comes from their environment including crustaceans like our friends the pill bugs true insects reptiles and fish and at least among the invertebrates on that list the most obvious symptom is a noticeable color change both inside and outside the animal infected animals can turn blue green yellow red or just be kind of shimmery depending on the virus now on its own that isn't too remarkable plenty of illnesses and infections change in organisms color but most infection-related color changes come from some sort of pigment a chemical that reflects certain colors and not others iridoviruses don't use pigments you can't put viruses in a test tube and extract a blue substance from them that's because the blue of infected pill bugs is an example of structural color it's the arrangement of the viruses inside an animal's cell that determines what colors the cell appears to be and ultimately it all comes down to the wave-like properties of light waves can interfere with each other reinforcing or cancelling out depending on the way that the crests and troughs line up with one another and that interference can alter what colors perceive for example red light's wavelength is about 700 nanometers so if you had two semi-reflective layers of something like layers of glass separated by about 700 nanometers the crests of the red light reflected by one would overlap with the crests of red light reflected by the other making it seem like the thing is tinted red but if the layers were separated by about 350 nanometers instead the crests reflected by one would overlap with the troughs reflected by the other no red light would come out at all even though both layers are reflecting red and the same goes for if you have individual atoms doing the reflecting instead of layers of glass so that's structural color the color you see doesn't just depend on the colors that are reflected it depends on the physical arrangement separation and reflective properties of whatever's doing the reflecting you can find structural color and butterfly wings birds beetles and plenty of other species and you can find it in animals tinted by iridoviruses that's because the viruses don't just spread all over the place when they reproduce inside a host animal's cells they arrange into rows and larger structures a lot like atoms do in a crystal smaller viruses tend to pack closer together leading to a blue tint that's seen in animals like roly-polies larger viruses tend to spread out more giving us redder animals instead erotoviruses have one more curve ball to throw though sometimes they cause this kind of characteristic color change but usually they don't two animals of the same species can even get infected by the same kind of eritovirus and one might change color while the other doesn't these are called covert infections and scientists still aren't sure what makes the viruses go down one path or the other partly because they're not sure why erotiviruses color animals in the first place iridescent infections are easy for other potential hosts to avoid which could potentially make it harder for the virus to spread however a bright bug is more likely to get eaten than one that's well camouflaged and a predator that eats an infected bug in one place could carry the infection elsewhere so some scientists think that obvious colors help the viruses spread far and wide while covert infections let viruses move around within a single population it's also possible that the colorfulness of the viruses isn't an adaptation in itself patent infections the ones that cause color changes happen when the virus reproduces really quickly inside a host's cells while covert infections tend to be when the virus reproduces more slowly and it could just be that when lots of viruses cram into a cell it takes less energy to arrange like a crystal than it would to do something else what we do know is that patent and covert infections tend to have different symptoms patent infections are just about universally lethal but they don't usually go full on pandemic and kill whole animal communities they just consistently infect small percentages of certain species anywhere from 100 individuals to one in a million covert infections are much more common estimates range from 10 to thousands of times as common depending on the host species and they're not nearly as lethal as patent infections they usually impact things like an animal's ability to move around or reproduce whether patent or covert though erito viruses can have some pretty big ecological effects they've killed off whole populations of tiger salamanders and bass and they've been found in bee colonies that have suddenly died suggesting they might play a role in colony collapse disorder too understanding the epidemiology of these viruses could help researchers predict and prevent outbreaks in species we don't want to lose like bees and it might even allow scientists to get the viruses to do some good like control invasive pests in the meantime they give physicists and biologists something to talk about at a dinner party well in the end at least those viruses might be useful it doesn't make life easier as a roly-poly but it's a silver lining at least thankfully not every blue in nature means death is knocking on your doorstep like with reindeer reindeer eyes specifically unless you know about some species i don't here's another one from olivia shine a light into the woods at night and you might see the glow of eyes staring back at you but the eyes aren't actually glowing they're reflecting light off a special layer of tissue found in some animals called a tapitum lucidum the color and shape of this eye shine can tell you what's peering at you from the darkness but things are more complicated if you're in the arctic regions of norway because there reindeer changed the color of that part of their eyes seasonally that's right the animals most famous for pulling santa's sleigh have eyes that change color to help them see in the darkness of winter animals that need to see well in low light like cats raccoons and even reindeer all have tapida lucida they sit in the back of the eyes right in between the outer layers of the eye and the retina the part that actually sees these thin tissues act as reflectors giving retina a second chance at absorbing light most animals have a particular color of eye shine which depends on the composition and structure of their tapitum lucida but the eurasian mountain reindeer is different it's the only one we know of that switches colors changing from a summery golden yellow to a deep blue in winter and scientists think that's a side effect of how their eyes have adapted to long periods of darkness the arctic summers where they live have 24-hour days and the winters include long stretches of night the animals compensate for this in part by making their retinas more responsive to low light in winter and it's believed they can see some wavelengths of uv light but that's not the most obvious adaptation to see better when it's so dang dark are reindeer's pupils open wide to let more light in kind of like yours if you go into a dark room but when a pupil stretches wider it also flattens the front of the eye ever so slightly which increases the pressure inside the eye since their pupils are constantly wide open during winter that pressure builds up squeezing the tiny collagen fibers of the deer's tapitum lucidum closer together and this compression causes the color change the tightly packed fibers strongly reflect shorter blue wavelengths of light while the more spaced out ones reflect longer yellow ones instead a phenomenon known as bragg's law researchers can actually compress a dissected piece of the reindeer's eye with a tiny weight and induce the same yellow to blue color change but the color isn't what's really important to the animal the compressed fibers also scatter light sideways through the retina instead of reflecting it out of the eye increasing the amount of light the retina can absorb while summer eyes reflect more than 95 percent of the light shown into them winter eyes reflect only 40 and that likely means the reindeer can see in what seems like total blackness the only downside to this amazing feat is that because light rays inside the eye are more scattered everything also looks a little fuzzier but that seems a small price to pay i wish i could trade a little blurriness for night vision oh i feel like reindeer need a cute little reindeer glasses speaking of very cute things siamese cats they have those adorable dark mittens and the little brown ears and the cute face but what gives them their distinctive look here's one more episode with a surprising and my father-in-law let me know absolutely mind-blowing answer seriously he loved this episode from a tiger's stripes to a jaguar's rosettes to a tabby's worlds cats come in lots of different colors and patterns normally we imagine that the way an animal looks is inherited from its parents basic genetic stuff but sometimes the origin isn't so simple like the coloring of some domestic cats is tied to their sex that's why orange cats are much more likely to be males and calicos and torties are almost always female but siamese cats are especially interesting because their recognizable coloration is actually dependent on temperature animals get their dark color because their bodies produce melanin melanin is the same protein responsible for variation in human skin tone and making you tan and it's produced thanks in part to the enzyme tyrosinase normally this enzyme does its job pretty well but in some breeds of mouse rabbit and cat and even in some human cases the enzyme doesn't quite work the same in particular virtually all siamese cats have a mutated version of the gene that codes for this enzyme so their tyrosinase is extremely sensitive to temperature so sensitive in fact that it unfolds and no longer functions at the average cat body temperature at around 38 degrees celsius that isn't great for the enzyme can't really do its job anymore but it does give the cats their adorable coloration without functional tyrosinase no melanin gets produced so most of the animal's fur is a creamy white it's essentially albino but siamese cats also have those super cute boots in that little brown mask and that's because tyrosinase is functional in their extremities like their tails legs noses and ears compared to their volume these parts of the body have a larger surface area for heat to escape from so these small and slender body parts lose heat more quickly than the cat's central core this is just like how your fingers and feet and nose are the first things to get cold when you step outside or how a narrow icicle is going to melt before a compact ice cube made of the same volume of water in a cat this means the face limbs and tail are just a few degrees cooler compared to the rest of the animal's body and that difference is enough to preserve delicate tyrosinases shape and function allowing it to color the fur if you ever get to see a newborn siamese kitten you can actually watch this process happen live when the cats are born they're totally white since the inside of the womb is a uniform and toasty 38 degrees celsius or so out in the world though the temperature around the kitten is cooler than its body so it loses heat to the environment especially from its tiny toes and tail within a few weeks the characteristic siamese color pattern starts to emerge as new fur grows and tyrosinase gets to work in the cat's extremities so unless you're keeping mittens on your kittens siamese cats will develop their trademark coloration all thanks to this delightful mutation cats are unsurprisingly just so great thank you for watching this episode of scishow compilations like this make me realize how much content we have put out over the years and we couldn't have done it without the support of our patrons on patreon and our channel members if you support scishow you're helping put more free educational videos out into the world to be watched by people who love them to be used in classrooms all over the place and we are really grateful for that if you want to learn more about supporting the show you can go to patreon.com scishow

Channel: SciShow

Views: 809,577

Rating: 4.8865561 out of 5

Keywords: SciShow, science, Hank, Green, education, learn, The Bizarre World of Living Color, coloration, color, 3 of the World’s Most Intensely-Colored Living Things, Why Aren’t Mammals More Colorful?, The Horrible Reason Rollie Pollies Are Sometimes Blue (, The Unique Reason Reindeer Change Their Eye Color, The Delightful Mutation Behind Siamese Cats

Id: UlsETcQlVRk

Length: 24min 15sec (1455 seconds)

Published: Wed Oct 07 2020