In life, and in biology, unlikely combinations can spur creativity and innovation. Cassandra Extavour, a Harvard evolutionary developmental biologist and professional singer, is a case in point. Extavour is equally at ease taking the stage as a soprano at Symphony Hall as she is serving as a keynote speaker at the Genetics Society of America conference, which had to be moved online in April. While many scientists have artistic interests, it is unusual to see someone reach the highest levels of excellence in both worlds.
Extavour’s professional life is a study in the creativity that arises out of unconventional juxtapositions, and so is her latest scientific research, recently published in the journal eLife. The research shows that a gene essential for insect development is a mashup of bacterial and insect DNA. That fusion of DNA occurred more than 500 million years ago, and today, many insects depend on the resulting gene, oskar, to make a germline — the cells that will make eggs and sperm.
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That’s an unexpected finding because traditionally, evolutionary geneticists have thought about evolution and adaptation as the tweaking of existing genes, as a result of natural selection on randomly arising small mutations. Evolutionary theory has less to say about big, radical mutations that seem to come out of left field from, say, a bacterial genome. But in recent years, several scientists have found evidence that sudden and massive changes in genetic sequences occurred in evolutionary history. The oskar gene is a good example. It allowed some insects to evolve a way of separating their germ cells from the rest of the cells in developing embryos, which is a key feature of multicellular organisms. When oskar came along, it was as if a stray musician walked into a foreign orchestra and somehow managed to lead the group into perfoming entirely new tunes.
Extavour grew up in Toronto with a Trinidadian father and Swiss and Hungarian mother and has been a musician all her life. She grew up playing the flute; she began singing as an undergraduate at the University of Toronto and started singing professionally toward the end of her undergraduate career. In contrast, her interest in science came relatively late, at the end of high school. After her undergraduate studies in molecular biology and genetics, Extavour studied for her PhD in Spain, then did postdoctoral training at the University of Cambridge in England. In 2007, she became a faculty member at Harvard’s Department of Organismic and Evolutionary Biology. She also performs as a soprano with the Handel and Haydn Society, Emmanuel Music, and Boston Baroque.
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When I asked her how she thinks about these two areas of her life, Extavour explained: “When you’re singing a piece, you can’t just be focused on the note that you are singing right then. You have to understand how that fits in the context of the piece, what came before it and what is the purpose of that note in the context of the whole thing, and where you’re going with that later. You’re working with other musicians, so you have to understand what they are doing at the same time as you. Trying to understand biological systems is very similar. There are extremely complex moving parts.”
Viviane Callier is a science journalist based in San Antonio.
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