A team of international researchers has uncovered a surprising genetic mechanism that influences the vibrant and complex patterns on butterfly wings. In a study published in the Proceedings of the National Academy of Sciences, the team, led by Luca Livraghi at the George Washington University and the University of Cambridge, discovered that an RNA molecule, rather than a protein as previously thought, plays a pivotal role in determining the distribution of black pigment on butterfly wings.
From shifting skink rainbows to dazzling hummingbird metallics, many creatures display brilliant hues created by nano-structures weaving wavelengths of light.
Researchers led by Utrecht University bioinformatician Aldert Zomer have now pinpointed genes that allow bacteria to make use of this vivid phenomenon too.
Where colors emitted by pigments are the leftover parts of the visible light spectrum that aren’t absorbed, structural colors arise from the way light interferes as it is reflected.
Scientists have developed a water-soluble, non-toxic fluorescent spray that makes fingerprints visible in just a few seconds, making forensic investigations safer, easier and quicker.
Latent fingerprints (LFPs) are invisible prints formed by sweat or oil left on an object after it’s been touched.
Traditional forensic methods for detecting fingerprints either use toxic powders that can harm DNA evidence, or environmentally damaging petrochemical solvents.
The University of Liverpool is part of a new study that reveals for the first time how particular scents can influence our perception of color.
In a paper, titled “Odors modulate color appearance,” published in the journal Frontiers in Psychology, an interdisciplinary research team of University of Liverpool psychologists and engineers undertook an experiment to determine if smell does indeed influence how we perceive color.
The experiment involved 24 participants aged 20 to 57 sitting in front of a screen in an isolation room with blacked out windows, and no unwanted sensory stimuli or odors.
Then an ultrasonic diffuser released one of six scents—caramel, cherry, coffee, lemon, and peppermint, plus odorless water as a control—into the room. The scents were chosen as they induced the most robust odor-color associations in the team’s prior work.
The participants were then asked to modify a square filled with a grayish color on a screen using two adjustable sliders—one yellow to blue and another one red to green—until they reached a color they judged as being devoid of any hue, that is, a perfect neutral gray color.
The results revealed that participants chose a more red-brown color gray when they smelt coffee, while opting for a yellow-brown version of the gray when the odor of caramel was pumped into the room.
sciencealert.com
Knowing more about how these matte structural colours are created will take us closer to producing paints free from pigments and dyes- a significant step forward in long-lasting, environmentally friendly materials for many applications.
From bird feathers to fruit skins, the natural world has two main ways of displaying colour: through pigment substances that provide selective colour absorption, or through structural colour – the use of microscopic structures to control light reflection.
Now scientists have devised a computer model that explains why the brightest matte structural colours in nature are almost always blue and green: because those are the limits of structural colour within the visible spectrum of light.
Besides giving us a better understanding of how the brightest blues and greens are created in the natural world, the research could also be important for developing vibrant, eco-friendly paints and coatings that won’t fade over time or release toxic chemicals.
“In addition to their intensity and resistance to fading, a matte paint which uses structural colour would also be far more environmentally-friendly, as toxic dyes and pigments would not be needed,” says physicist Gianni Jacucci from the University of Cambridge in the UK.
The world is full of colors. Almost all of them can be described by a wavelength of visible light, but there are some colors out there that are just in your head!
Hosted by: Hank Green
(Source: youtu.be)
smithsonianmag.com
Using genetic editing, scientists isolated just two genes that play a major role in making butterfly wings as pretty as they are
There are some 20,000 species of butterflies fluttering in skies around the world—each one with its own uniquely beautiful wings filled with spots, stripes, colors and more in seemingly every imaginable pattern. Scientists have long assumed that these complex designs were governed by an equally complex series of genes, similar to traits like human eye color. But new research suggests that may not be the case.
eurekalert.org
Scientists say that, as dinosaurs split from this lineage after turtles, and were closely related to birds, this strongly suggests that they would have carried the CYP2J19 gene, and had the enhanced 'red vision' from the red retinal oil.
Earlier this year, scientists used zebra finches to pinpoint the gene that enables birds to produce and display the colour red.
Now, a new study shows the same ‘red gene’ is also found in turtles, which share an ancient common ancestor with birds. Both share a common ancestor with dinosaurs.
The gene, called CYP2J19, allows birds and turtles to convert the yellow pigments in their diets into red, which they then use to heighten colour vision in the red spectrum through droplets of red oil in their retinas.
Birds and turtles are the only existing tetrapods, or land vertebrates, to have these red retinal oil droplets. In some birds and a few turtle species, red pigment produced by the gene is also used for external display: red beaks and feathers, or the red neck patches and rims of shells seen in species such as the painted turtle.
The scientists mined the genetic data of various bird and reptile species to reconstruct an evolutionary history of the CYP2J19 gene, and found that it dated back hundreds of millions of years in the ancient archelosaur genetic line - the ancestral lineage of turtles, birds and dinosaurs.
The findings, published today in the journal Proceedings of the Royal Society B, provide evidence that the 'red gene’ originated around 250 million years ago, predating the split of the turtle lineage from the archosaur line, and runs right the way through turtle and bird evolution.
Scientists say that, as dinosaurs split from this lineage after turtles, and were closely related to birds, this strongly suggests that they would have carried the CYP2J19 gene, and had the enhanced 'red vision’ from the red retinal oil.
This may have even resulted in some dinosaurs producing bright red pigment for display purposes as well as colour vision, as seen in some birds and turtles today, although researchers say this is more speculative.
What Causes Color Blindness? By Discovery News
Some people in the world aren’t able to see many colors. The condition is called color blindness, but what exactly causes it?
(Source: youtube.com)
This Woman Sees 100 Times More Colors Than The Average Person
When Concetta Antico looks at a leaf, she sees much more than just green. “Around the edge I’ll see orange or red or purple in the shadow; you might see dark green but I’ll see violet, turquoise, blue,” she said. “It’s like a mosaic of color.”
Antico doesn’t just perceive these colors because she’s an artist who paints in the impressionist style. She’s also a tetrachromat, which means that she has more receptors in her eyes to absorb color. The difference lies in Antico’s cones, structures in the eyes that are calibrated to absorb particular wavelengths of light and transmit them to the brain. The average person has three cones, which enables him to see about one million colors. But Antico has four cones, so her eyes are capable of picking up dimensions and nuances of color—an estimated 100 million of them—that the average person cannot. “It’s shocking to me how little color people are seeing,” she said.
Although tetrachromats have more receptors in their eyes, their brains are wired the same way as a person with normal vision. So how can a brain like Antico’s change to see more colors? Like anything else, practice makes perfect, even when it comes to neural pathways.
For years, researchers weren’t sure tetrachromacy existed. If it did, they stipulated, it could only be found in women. This is because of the genes behind color vision. People who have regular color vision have three cones, tuned to the wavelengths of red, green, and blue. These are connected to the X chromosome—men have one, but women have two. Mutations in the X chromosome cause a person to perceive more or less color, which is why men more commonly have congenital colorblindness than women (if their one X chromosome has a mutation). But the theory stood that if a woman received two mutated X chromosomes, she could have four cones instead of the usual three.