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Circles in Human Evolution: Q&A with Abigail Wark

August 9, 2013

circles_in_human_evolutionAbigail Wark is a research fellow in the Tabin Laboratory in the Department of Genetics at Harvard Medical School. Her research focuses on understanding the causes and consequences of variation in uniquely human traits. She is the Project Director for Circles in Human Evolution: the Areola, a citizen science collaboration with the PGP that is gearing up to provide the worlds first genetic study of diversity in human areolas. has partnered with the Tabin Laboratory and Circles in Human Evolution to create a third party research opportunity for PGP volunteers. Abby recently sat down with us to answer questions about this project.

Why study the genetics of human diversity?

We are living in the golden age of human genetics. The bulk of what we know about genetics so far has to do with genes that have gone awry. Focusing on genetic dysfunction makes sense because we want to prevent and cure human disease. But strongly detrimental genetic variants are a very small part of human genetic diversity. The truth is that most of the variants we carry in our genomes do not cause us catastrophic problems. These variants help make each of us who we are; they make us biologically unique. But while we have learned so much about genetic origins of disease, we know almost nothing about the genetic signature of healthy diversity. The tools are available now to update our view on this, to examine and understand a bigger slice of human biodiversity.

Are there meaningful consequences to this genetic diversity?

Of course! Nature is full of examples where genetic diversity can have real functional significance. Sensory systems provide dramatic examples of this because they can lead animals to interpret the world in completely different ways. For example, think of an insect with a gene that enables it to see UV light. That insect has access to information that you and I don’t have. The same thing is true for much more subtle cases of diversity. If you are a fish, subtle changes to your sensory systems can affect your likelihood to school, which has big ramifications for how you live your life as a fish, how your respond to predators, etc. I think we all know intuitively that this is true for humans too. We vary in all kinds of traits, from physical traits like height and hair color to sensory traits like taste or odor perception. And there’s reason to believe that these traits can impact how we live our lives, from what foods we eat to how well we deal with hot weather. The era of personal genomics offers the chance to understand what this diversity is made of and what role it plays in our lives.

Why did you choose to study the areola?

Areolas probably seem like such a strange topic! But they turn out to be pretty fascinating. Areolas are the circular markings that surround the human nipple. Did you know that no other animals have these spots? They are defining marks of our species! The fact that areolas are circular is really significant for this study. Circles are one of nature’s simplest forms. Many interesting human traits are the opposite of this – they are extremely complex. The genetic recipe for building a human hand or brain is complicated which makes it very challenging to draw a line from even the simplest genetic changes to effects on human traits. But circles are simple to build and simple to change. It turns out that the simplicity of circles might give us a foothold for discovering the genetics pathways that define human traits.

So that is why areolas are a practical, though somewhat unusual topic, for studying human genetics. That said, one thing that has made this project really fascinating for us is that areolas are much more than just circular markings. In women, the pigmentation of the areola is believed to signal fertility and some evidence suggests that this may be one of the first indications of pregnancy. Areolas play an important role in nursing, providing both a visible target and a pheromonal attractant for newborn infants. In fact, the number of areolar glands, which differs from person to person, has been associated with infant weight gain. Developmentally, these glands are related to the mammary glands and one of the really exciting angles of our work is to see whether the areola might provide a window into the inner biology of breast. If it does, the results could be really important for many aspects of breast health, from lactation to cancer.

Why are you using a citizen science approach? What role do participants play?

Citizen-science is a movement to give non-scientists an active role in scientific discovery. I like to think that we are all potential scientists, just with different amounts of training. As children, many of us took delight in the act of discovery. We explored our backyards, tried to grow plants, observed animals, and mixed toothpaste and ketchup to see what we would get. As I see it, some of those kids became scientists and most did not, but there’s no reason to exclude non-scientists from that sense of discovery. In our project, participants become part of our field research team. They are given the tools and information they need to make observations about their own bodies. They share that data with us and our job is to compile and analyze the findings for the whole community. The whole project is a partnership.

Can participants sign up?

Yes, please do sign up! This is a PGP-specific study, so only PGP participants can join. This limits the number of people who can help, so we need you and all of your PGP friends! I want to emphasize that both men and women are encouraged to join our study. Submitting photographs through our server is very helpful, but is completely optional. Your data is still useful to us even if you choose not to include photographs.

To read more about the study or to sign up, please go to:

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