July 2020    
Research and news | FAQs and resources
University updates
  The nature of color  
  Nature is painted with pigments—molecules that produce color by absorbing certain wavelengths and reflecting others. Chlorophyll is the pigment that makes plants green; melanin is a pigment that gives humans our eye, hair, and skin color. But some colors found in nature—especially vibrant greens and blues—are a trick of light.  
  Winged evolution  
Blue buckeye butterfly
  Buckeye butterfly (Junonia coenia) selectively bred to shift wing color from brown to blue. (Photography by Edith Smith)  
  True (pigmented) blue animals are extremely rare.  
  Blue jays aren’t blue; they’re brown. Blue morpho butterflies aren’t blue either. These brilliant blues are examples of structural color, created by the microscopic shape of a material that bends and scatters light in a way that amplifies certain visible wavelengths. Imagine a soap bubble: the film is clear, but you see swirls of color when it floats in sunlight. These nanostructures are what make peacock feathers, beetle carapaces, and butterfly wings so vivid.  
  Buckeye butterflies are usually brown with small (structural) blue flecks. (So far, only the olivewing butterfly is known to have blue pigment.) Over the course of a year, a butterfly breeder mated buckeyes that had the most blue, and this artificial selection forced a “rapid evolution” and created blue-winged buckeyes. Marine Biological Laboratory scientists took the opportunity to study the evolutionary mechanisms that change the tiny overlapping scales that give butterfly wings their color.  
  Color coded  
The giant squid genome has been fully sequenced, allowing scientists to study genes unique to cephalopods. These include reflectins, cephalopod-specific proteins thought to be important for the structural colors used in camouflage.
The relationship between some monogamous birds depends on how colorful the male is—in positive and negative ways.
A single gene controls whether Heliconius cydno butterflies will have white or yellow spots. That same gene may also influence preference for white- or yellow-spotted mates.
  Dream in color  
Sleeping octopus
  Cephalopods use both pigment and structural color for camouflage.  
  Last fall, Heidi the sleeping octopus put on an amazing technicolor dream show. Was she camouflaging based on her dreamworld?  
  Recent studies show that cuttlefish change color in phases that suggest they experience REM sleep—which is when humans dream. UChicago neuroethologist Daniel Margoliash says sleep stages seem to have evolved multiple times in vertebrates, so why not in cephalopods?  
  You can’t just ask animals if they’re dreaming, but Margoliash has shown that sleeping birds sometimes have the same brain activity as singing birds. So if a sleeping octopus is ever found to have the same brain waves as a feeding octopus, maybe Heidi was dreaming of feasting on a crab.  
  In case you missed it  
Ancient DNA: Geneticists are now able to recover DNA from prehistoric remains.
Skeeterish: Scientists attack mosquitoes at the human, bug, and microbe levels.
  Support UChicago biological sciences.  
  COVID 2025: Our World in the Next 5 Years is a video series in which leading scholars discuss how the coronavirus will change our world and what steps are crucial now to shaping that future.

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