The Science of Color: How Butterflies Paint their Wings | Biology Creating Color via Nanoengineering

Summary

In this engaging presentation, the speaker takes us on a journey to the Amazon rainforest in southeastern Peru, where they explore the science of color in nature. Using examples from human eye color, skin pigmentation, and butterflies, the speaker explains how different creatures create vibrant colors through pigments and structural coloration. Special attention is given to butterflies, showcasing their incredible nano structures that produce iridescent colors. The talk also touches on bio-inspiration, with insights into how engineers are drawing from nature to develop technologies like solar panels. The science behind the creation of colors is explored through both biological processes and fascinating real-world applications.

Takeaways

• 😀 The speaker shares their experience working as a field biologist and National Geographic Explorer in southeastern Peru, exploring the Amazon rainforest and its wildlife.
• 😀 The concept of color creation in nature is introduced, focusing on how animals and plants produce a vast array of colors using biological mechanisms.
• 😀 Chlorophyll, the molecule responsible for the green color in plants, absorbs blue and red wavelengths, leaving green visible due to the light not absorbed.
• 😀 Human eye color variation is explained, with melanin levels influencing the range from brown to blue eyes. The greenish hue in some eyes is due to light scattering.
• 😀 Tanning in humans is explained by melanocytes in the skin that respond to UV radiation by producing melanin to protect the skin from DNA damage.
• 😀 Redheads have a genetic mutation (MC1R) that makes their melanocytes more efficient at producing a reddish pigment rather than the darker melanin, affecting their ability to tan.
• 😀 Butterflies, specifically Lepidoptera, are highlighted as the masters of color, with each wing scale producing specific colors. These scales are responsible for creating intricate patterns.
• 😀 Structural coloration in butterflies, like in the Blue Morpho, is based on microscopic structures on their wings that manipulate light to produce vibrant colors without pigments.
• 😀 The phenomenon of structural color involves light interacting with nano-structures, creating effects like constructive interference to enhance specific wavelengths, like blue in the Blue Morpho butterfly.
• 😀 The process of metamorphosis in butterflies, where caterpillars undergo transformation into butterflies, includes the development of scales that contribute to color creation, including both pigments and structural colors.
• 😀 The glass wing butterfly (Greta oto) showcases the use of transparent wings, which are made possible by micro-structures that diffuse light to avoid glare, a principle now applied in technology like solar panels and LEDs.

Q & A

What inspired the speaker to explore the science of color?

The speaker's work as a field biologist and National Geographic Explorer in the Amazon rainforest, particularly observing the colors of butterflies and moths, inspired the exploration of the science of color.

What role does chlorophyll play in the color of plants?

Chlorophyll absorbs blue and red wavelengths of light, leaving behind green light, which is why plants typically appear green.

How does human eye color vary based on melanin?

The color of human eyes is determined by the amount of melanin in the iris. Darker eyes, like brown, contain more melanin, while lighter eyes, like green, result from a lack of melanin and how light interacts with the surface of the iris.

What is the role of melanocytes in human skin color?

Melanocytes are cells in the skin that produce melanin in response to ultraviolet (UV) radiation, leading to tanning as a protective mechanism against UV damage.

Why are redheads unable to tan as easily?

Redheads have a mutation in the MC1R gene, which makes their bodies less effective at producing the darker form of melanin needed for tanning. Instead, they produce more pheomelanin, resulting in lighter skin and difficulty tanning.

What is structural coloration in butterflies?

Structural coloration in butterflies, such as in the Blue Morpho, is created not by pigments but by microscopic structures on their wings that manipulate light, producing vivid colors through physical interaction with light, like interference or diffraction.

How does the Blue Morpho butterfly achieve its blue color?

The Blue Morpho butterfly achieves its blue color not through pigment but through microscopic scale structures on its wings that cause constructive interference, amplifying certain wavelengths of light (blue) while canceling others.

What happens when ethanol is dropped on a Blue Morpho butterfly wing?

When ethanol is dropped on a Blue Morpho butterfly wing, it temporarily changes the refractive index of the nano structures on the wing, altering the wavelength of light that is reflected, which causes the wing color to change.

What is the significance of the glass-wing butterfly’s transparency?

The glass-wing butterfly has transparent wings, which is a rare trait among terrestrial organisms. Its wings are engineered with microscopic structures that diffuse light, reducing surface reflections and making the butterfly more difficult to detect.

How have the structures on the glass-wing butterfly’s wings been applied in technology?

The microscopic dimples on the glass-wing butterfly’s wings, which diffuse light, have inspired innovations in technology, such as the design of solar panels, where light diffusion helps in collecting more light efficiently.