Unlocking the mystery of how insects got their wings

Hundreds of millions of years ago, two tissues fused to form wings on ancient beetles, according to the findings of a genetic experiment

Asher Elbein 

Beetle wings are often hidden. Nestled behind armoured shields on the beetle’s back, they unfurl in whirring sheets, whisking their clumsy owners from danger. Beetles don’t have more than two sets of wings – unless they’re in Yoshinori Tomoyasu’s lab.

In research recently published in the Proceedings of the National Academy of Sciences, Tomoyasu and his co-author, David Linz, genetically engineered beetle larvae with wings on their abdomens, part of an attempt to unpack one of evolution’s greatest mysteries: how insects gained the ability to fly.

Insects took to the empty skies sometime between 300 million and 360 million years ago, long before birds, bats or pterosaurs. Wings allowed them to conquer new habitats and ecological niches, and insecta quickly established themselves as one of the most diverse and successful animal classes, a position they still hold today.

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Secrets of butterfly wing patterns revealed by gene hacking

 18 September 2017

By New Scientist staff and Press Association

Butterfly wings have been given make-overs by scientists who tweaked a “painting gene” to change their patterns and colours.

The research has major implications for understanding how the so-called “rules of life” – genetics and evolution – shape biodiversity.

The team used the powerful new gene-editing technique CRISPR/Cas9 to study the role of the WntA gene in creating one of nature’s greatest artworks, the butterfly wing.

By removing the gene from seven butterfly species, they were able to radically alter the insect’s appearance. Wing patterns and colours changed in ways that were unexpected.

The research showed how WntA acted as a master gene responsible for the trademark look of different butterflies.

Architectural genes

Lead scientist Arnaud Martin, from George Washington University in the US, said: “We know why butterflies have beautiful coloured patterns. It’s usually for sexual selection, for finding a mate, or it’s some kind of adaptation to protect themselves from predators.

“What is more mysterious is how do they do it. How do you make stripes and dots, how do you make complexity, how do you fine-tune a given feature during long evolutionary time scales?

“CRISPR allowed us to not only describe that this gene has evolved multiple roles within a single species, it also enabled a massive comparison between species and showed that pattern evolution has consisted of variations on a common theme.”

More than 20,000 distinct species of butterflies live in the world today.

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How the butterfly got its spots

Date: June 15, 2016

Source: Cornell University

By tweaking just one or two genes, Cornell University researchers have altered the patterns on a butterfly's wings. It's not just a new art form, but a major clue to understanding how the butterflies have evolved, and perhaps to how color patterns -- and other patterns and shapes -- have evolved in other species.

By using the new method of CRISPR genome editing, researchers cut out a gene known as spalt, and produced a butterfly lacking the large round markings known as eyespots. In another experiment, they removed a gene known as distal-less and produced more and larger eyespots. The experiments also produced changes in other parts of the wing design.

The distal-less gene in particular revealed itself as a jack-of-all-trades gene that plays roles in shaping several parts of the body. Deleting it not only caused the butterfly to have extra eyespots, but to have shorter legs and antennae.

"People suspected these genes had something to do with wing patterns but nobody had proved it," said Robert Reed, associate professor of ecology and evolutionary biology. "It probably takes dozens or hundreds of genes to make an eyespot, so it was remarkable to find that only one or two genes are required to add or subtract these complex patterns. It is a beautiful demonstration of how animals are assembled as modules, much like a model kit." Reed and postdoctoral researcher Linlin Zhang report their results in the TK issue of the journal Nature Communications.

Butterfly wing patterns are of special interest to evolutionary biologists because they provide an easily accessible model of how natural selection chooses from many possible variations. "Variation is the raw material of evolution," Reed said. CRISPR genome editing technology offers great potential for understanding how this variation originates he added.

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How planthoppers got (and changed) their wings

Date:

March 18, 2015

Source:

Duke University

Summary:

Each year, rice faces a big threat from a sesame seed-sized insect called the brown planthopper. Now, a study reveals the molecular switch that enables some planthoppers to develop short wings and others long based on environmental conditions such as day length and temperature -- a major factor in their ability to invade new rice fields.

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Do butterfly wing patterns really mimic predator eyes?

23 July 2014 Last updated at 05:32

By Ella Davies

Science writer

A bumper crop of spikey black caterpillars have appeared on the nation's nettles this summer.

Clad in velvet coats peppered with white dots, the creatures have been sunning themselves and munching through the weeds in remarkable numbers prompting a flurry of enquiries and reports to the charity Butterfly Conservation.

They might not be so familiar in this form but the insects will grow up to be arguably Britain's most colourful and recognisable butterfly - the peacock.

As they prepare for their annual Big Butterfly Count, experts at the charity are predicting a bonanza of the butterflies.

Last year, the species surged to third position in the survey which asks the public to record how many butterflies they see in 15 minutes of sunny weather.

Following on from this success, peacocks emerged in good numbers after their winter hibernation according to Butterfly Conservation's Surveys Manager Richard Fox. The warm, dry weather since the spring has provided ideal conditions for breeding, egg-laying and the development of caterpillars.

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Deciphering Butterflies' Designer Colors: Findings Could Inspire New Hue-Changing Materials

July 17, 2013 — Butterfly wings can do remarkable things with light, and humans are still trying to learn from them. Physicists have now uncovered how subtle differences in the tiny crystals of butterfly wings create stunningly varied patterns of color even among closely related species. The discovery, reported today in the Optical Society's (OSA) open-access journal Optical Materials Express, could lead to new coatings for manufactured materials that could change color by design, if researchers can figure out how to replicate the wings' light-manipulating properties.

"It was very exciting to see how nature can create a nanostructure that's not easy to replicate by humans," says Kok Wai Cheah, a physicist at Hong Kong Baptist University. He and his colleagues are the first to investigate the color-creating mechanisms in multiple butterfly species within a single genus.

The three tropical butterflies the researchers studied all display iridescence, a property of materials that change color depending on the viewing angle, but they do so with different colors. Papilio ulysses, the Ulysses butterfly or blue mountain swallowtail, appears bluish green when seen from above. Its cousin Papilio peranthus, by contrast, looks yellowish green from above, and a third relative,Papilio blumei, the green swallowtail, is more of a deep green. All three shift toward deep blue when viewed from a sharp angle.

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Cicada Wings Are Self-Cleaning

(ISNS) -- As 17-year cicadas wriggle out of the ground all over the northeastern U.S. this spring, they'll be reemerging into a world that understands them a little better. Researchers now find the design of their wings can cause filth to jump right off of them with the aid of dew, findings that might help lead to better artificial self-cleaning materials. 

Scientists had known that cicada wings are super-water-repellent, or super-hydrophobic. This is different from a great many substances that are simply water-repellent, or hydrophobic — for instance, oil and water famously do not mix. But a number of surfaces such as lotus leaves can make themselves even more water-repellent by covering themselves with microscopic bumps, so water drops can float on top much as mystics can lie on beds of nails. For example, cicada wings are covered in rows of waxy cones about 200 nanometers or billionths of a meter high. In comparison, the average human hair is roughly 100 microns or millionths of a meter wide. 

When it rains the super-hydrophobic nature of cicada wings can help them get clean — droplets rolling or splashing off them can remove soil, dust, pollen and microbes. But what if there is no rain, especially in the four to six weeks adult cicadas have to live above ground before dying? 

Now scientists find rain is not necessary to keep cicada wings clean. Apparently, grime can simply leap right off them, given dew. 

Mechanical engineer Chuan-Hua Chen at Duke University in Durham, N.C., and his colleagues were investigating a number of natural and artificial super-hydrophobic surfaces when they noticed drops of water at times rapidly disappeared. They were mystified by this behavior for years until they made observations from a different angle — they used a high-speed video camera to watch the droplets from the side of these materials instead of from above. 

"That's when we saw them jumping upward," Chen recalled.

Continued: http://www.livescience.com/29146-cicada-wings-are-self-cleaning.html

Bats Save Energy by Drawing in Wings On Upstroke

ScienceDaily (Apr. 11, 2012) — Bat wings are like hands: meaty, bony and full of joints. A new Brown University study finds that bats take advantage of their flexibility by folding in their wings on the upstroke to save inertial energy. The research suggests that engineers looking at flapping flight should account for wing mass and consider a folding design.Whether people are building a flying machine or nature is evolving one, there is pressure to optimize efficiency. A new analysis by biologists, physicists, and engineers at Brown University reveals the subtle but important degree to which that pressure has literally shaped the flapping wings of bats.

The team's observations and calculations show that by flexing their wings inward to their bodies on the upstroke, bats use only 65 percent of the inertial energy they would expend if they kept their wings fully outstretched. Unlike insects, bats have heavy, muscular wings with hand-like bendable joints. The study suggests that they use their flexibility to compensate for that mass.

"Wing mass is important and it's normally not considered in flight," said Attila Bergou, who along with Daniel Riskin is co-lead author of the study that appears April 11 in theProceedings of the Royal Society B."Typically you analyze lift, drag, and you don't talk about the energy of moving the wings."

The findings not only help explain why bats and some birds tuck in their wings on the upstroke, but could also help inform human designers of small flapping vehicles. The team's research is funded by the U.S. Air Force Office of Sponsored Research.

"If you have a vehicle that has heavy wings, it would become energetically beneficial to fold the wings on the upstroke," said Sharon Swartz, professor of ecology and evolutionary biology at Brown. She and Kenneth Breuer, professor of engineering, are senior authors on the paper.

Contined:  http://www.sciencedaily.com/releases/2012/04/120411084133.htm