Secrets in the wings of butterflies

Nipam Patel is a developmental biologist studying the animal world at the genetic level. His research into butterflies and crustaceans is opening new doors in our understanding of color visualization, tissue regeneration, and the evolution of species.

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I’m currently the Director of the Marine Biological Laboratory in Massachusetts, an international center for research and education in biological and environmental science. I’m also a Professor at the University of Chicago.

I think of myself as a developmental biologist. I’m fascinated by understanding how arthropods – things like insects, millipedes and centipedes – generate the repeating segments of their bodies. I’m also interested in coloration in butterflies. They use a fascinating phenomenon whereby the color on their wings is created through refraction rather than by pigment.

Yes, I started collecting butterflies when I was just eight years old. I found a dead one in our yard, and I read up on how to mount it. I still have that one in my collection. Then I convinced my mother and father to help me sew nets and I started collecting more. Today, I have tens of thousands.

While collecting butterflies began as a hobby, a number of years ago I decided to start doing some scientific research with them too. This has led to one of my current topics in the lab, which is looking at how they grow scales to create the color on their wings. Blues and greens are especially interesting, as they’re created by an amazing phenomenon of light on the surface of the wing. We call this phenomenon structural coloration.
  

Think about a soap bubble in the sun. The soap that the bubble is made of does not have any color to it, yet it shows all the colors of the rainbow. This is because the light hitting the bubble’s surface reflects off both its outside and inside. As the bubble is incredibly thin, the light waves interact with one another. Some colors get amplified and look brighter, while other colors get destroyed and disappear.

Butterflies use this phenomenon in a very sophisticated way, with tiny nanostructures on their wings creating light refraction that we perceive as color. People may be familiar with the bright metallic-blue morpho butterflies. There is actually no blue pigment in their wings – it’s just the way the light refracts that creates the color.

What we’re trying to do is understand the genes behind phenomena of this type.

A few years ago, we started using this amazing technology called CRISP-Cas9 genome editing. This allows us to go in and manipulate the genes of just about any organism.

In my own lab we also work on arthropod crustaceans – those little grey creatures you see jumping in the sand at the beach – as we’re interested in how they get the right leg on the right segment. Thanks to CRISP-Cas9 genome editing, we can now change the pattern of their legs.

We’re trying to do some of those same things with butterflies, changing the colors and patterns on their wings to really understand how the coloration phenomenon works at a detailed level.

Color really is one of those spectacular phenomena.

In physics, we can use a prism to split white light into the colors of the rainbow, and we can measure the wavelengths of light to give the colors real physical meaning. On the other hand, color is a human perception. We talk about color because that’s the way our mind processes the information we have.

It’s one of those fascinating things where there is both the physical reality to color, and there is the human perception of color. For example, there are wavelengths of light that we would say are yellow, but the human brain can also mix together different colors to create yellow, even though they are not yellow wavelengths. It’s about the way our eyes perceive those wavelengths and our brains process the information. I’ve always been fascinated by this.

People often look at the work scientists do and ask how it benefits humans. What I think the public needs to understand is that many of the huge discoveries in health and medicine came from very basic science that wasn’t expected to lead to any great innovation. Scientists were just interested in answering basic questions.

When it comes to the work we’re doing with butterflies, there is outside interest in the phenomenon of structural coloration as a way to make color that does not fade. For example, the problem with paint is that it often fades over time as sunlight hits it. But if you have something that is structurally colored – instead of colored by a pigment – then it wouldn’t be destroyed by light and would maintain its color for a long time.

We also work on transparency in butterflies, which have evolved an anti-glare coating. If you wear glasses, for example, you can get lenses that do not reflect light. Butterflies figured out how to do this with their wings about 50 million years ago. We can look at this to see if it’s possible to apply in our daily lives. For example, if we had surfaces that didn’t reflect as much light, they may make improved solar cells.

For a lot of animals – including us humans – if we lose an arm or a leg, we don’t have the ability to regrow it. But there are other animals that we work on here in the lab – such as the crustaceans I mentioned earlier – that can in fact regrow limbs in a relatively short period of time.

Scientists now are really fascinated by whether they can learn the secrets of these animals to the benefit of humans. We may not be able to regrow a whole arm, but understanding the tricks these animals are using may allow people to recover quicker from spinal cord injuries, for example.

Thinking about how humans are going to evolve is really tough at the moment, because evolution typically takes tens of thousands or millions of years. But now we have an incredible ability to control our environment through technology, and potentially to edit our genes too. Humans have developed the ability to evolve in ways outside of what we think of as classic biological evolution.

There’s a lot of well-deserved discussion about what we should be doing with technology like this. It’s the genie in the bottle – once you let it out, you can imagine all sorts of things you can do.

Many of those things will really be to the betterment of human society, such as working with agriculture and plant engineering to increase food yields. But of course there are also other things scientists can do that we would automatically recognize as not being a good idea.

I feel that as responsible researchers we should engage the public in discussing these issues. I think that’s very important. The people who pioneered CRISPR-Cas9 technology are highly conscious of this, and they are very engaged with the public and with ethicists on thinking about what we do. The questions are not easy ones to answer, but scientists tend to be pretty careful and have safeguards to make sure that things don’t go wrong.

In the future, one of the biggest challenges we are going to face is the ability to synthesize large amounts of data. Right now, we can look at specific genes, pathways and networks, but understanding the condition of an organism is really about processing a huge amount of input on all the different genes and the environment in which the organism exists. Figuring out a way to model, manipulate and experiment with all this is really going to drive some of the directions we go in biology. We need AI to take this data and give it to us in a form that we understand.

A good example that illustrates this challenge is the sequencing of the human genome. We put a lot of resources into that project and now it’s accomplished. We’ve learned a lot, but in so doing we’ve also learned that we know very little. We have the complete sequence of the human genome, and now the challenge is to make sense of it. We have the data, but how do we read it? This is proving to be incredibly complicated, and each step we take makes us realize that there are often more questions than answers.