Carl Zimmer To Speak At Bio-IT World, Tackle Heredity, Genes, And How Our Understanding Of The Two Is Changing

By Allison Proffitt

May 9, 2018 | “There are aspects of heredity that have been incredibly controversial for decades and even centuries,” Carl Zimmer says. Even before Gregor Mendel tracked traits in pea plants, humans were developing theories about how we ended up both similar and different from our parents. And ever since Mendel, we have discovered more about our genes, inheritance, what it means to pass on parts of ourselves.

Carl Zimmer traces our growing understanding in his new book, She Has Her Mother’s Laugh, which will be released by Dutton on May 29, 2018. Bio-IT World Conference & Expo attendees will get a sneak peek at the book next week when Zimmer gives the closing plenary address and stays to sign copies.

Zimmer is an award-winning science writer, columnist for the New York Times, and the first journalist to have his genome sequenced, get the raw data from Illumina, and share it with researchers from the New York Genome Institute, Weill Cornell, Yale, Brigham and Women’s Institute and others. He discovered that genomics is at once benign and boring, and overwhelmingly complex and interesting.

“My genome was very boring at first. It was very boring when all that I was learning was whether I had some very short list of genetic variants that are linked to diseases. I’m glad that it was boring! It was a big relief to me, and it’s also a big relief that my children are not inheriting anything especially dangerous from me,” Zimmer said. “But then I took the next step, which was to get my hands on the raw data of my genome.”

The act of getting the raw data was fairly complicated, Zimmer said. He enrolled in a study Robert Green was doing at Brigham & Women’s exploring how people react to knowing their genetic information. Months—and many consent forms—later, Illumina sent him a hard drive of his data. That’s when it got interesting. Zimmer shared his raw data with researchers at Weill Cornell, Yale, and the New York Genome Center to see what they could discover.

“It was a huge amount of fun watching them take that raw data and put it through their own pipelines,” Zimmer told me, but he also felt uncomfortable pointing out discrepancies to the scientists he worked with. “I still remember, I was sitting down with Chris Mason at Weill Cornell. He and his students were so enthusiastically going through their findings with me… and they showed me, among other things, how many SNPs I had. Not too long beforehand I’d gone through the same experience with Mark Gerstein and his team at Yale, and their numbers for my SNPs were off by hundreds of thousands. … It was a little awkward with Chris, but I just said, ‘Hey, I got a very different number from Mark Gerstein,’ and Chris just shrugged and said, ‘Oh yeah, that happens.’”

It turns out, there’s a lot about our current understanding of our genes and how we pass them on that isn’t perfectly clear cut.

“We tend to think about heredity as being just vertical. In other words that things can only get passed down from a parent to offspring. Certainly, for most of our genes that true, but for other species, especially bacteria, you can acquire DNA from some totally unrelated microbe. They can connect the little tube from one microbe to another and they trade genes; it’s called horizontal gene transfer,” Zimmer explains.

And he argues that we are sharing or passing down more than just genes. Our microbiomes, epigenetics, and even aspects of culture itself are shared and passed down in a way that Zimmer argues is heritable. “In some ways culture is like our genes, passed down vertically though time. But if people from two cultures make contact and one of them learns something from the other, that’s kind of like the horizontal gene transfer in bacteria,” he says.

In She Has Her Mother’s Laugh, Zimmer traces the history of our understanding of heredity from Hippocrates, who believed both men and women produced semen and new life was formed when the two were mixed, through the innumerable twists and turns that expanded our understanding of how we come to be: from the Habsburg’s royal bloodline to Carl Linnaeus, Jean-Baptiste Lamarck, Charles Darwin, Gregor Mendel, Hugo de Vries, eugenics in America, genome sequencing, CRISPR, and gene drives.

Along the way, Zimmer says, we’ve learned that “there are some problems in biology that are a lot simpler than we realize, while there are a lot of problems that are a lot harder than we’d like to think.”

It may be time, he suggests, to shift some of our understanding of heredity to keep up with what we are observing. He proposes in She Has Her Mother’s Laugh that we start with the very definition of the word.

“We cannot understand the natural world with a simplistic notion of genetic heredity. And some scientists have likewise argued that we must expand our definition of heredity again, to take into account other channels as well—be they cultural, epigenetic marks, hitchhiking microbes, or channels we don’t even know about yet…. [i]t’s time to build mathematical equations that can unite genetic and nongenetic forms of heredity in a single description.”

Editor’s Note: Carl Zimmer will offer the plenary address on Thursday, May 17, at the Bio-IT World Conference & Expo in Boston. Register to attend the full conference, or reserve your free keynote and Expo pass to hear Zimmer speak.