In June, I attended an interview and book signing with author and science journalist Carl Zimmer at the Denver Museum of Nature and Science. Zimmer was there to talk about his new book She Has Her Mother’s Laugh, a look into the history of how we understand heredity and biological legacy.
The first question he was asked in the interview regarded his own children: How did it feel to know that any strange or dangerous traits lurking in your genome could be passed down, without your knowledge or control, to your daughter?
Zimmer answered the question in two ways. First, from his own personal experience: essentially, that it was really, really scary. How can you be responsible for a decision as huge as having a child when you know you might accidentally give them a rare, incurable genetic disease? Or possibly worse — they might be short!
In the book he expands on that point: “I had willingly become a conduit for heredity, allowing the biological past to make its way into the future. And yet I had no idea of what I was passing on.”
It can be terrifying to be so ignorant about what’s in your genes and yet know that you will pass it down to future generations.
Then he answered the question in a different way — by talking about what we canknow about our own genetics, and how people have tried throughout history to decipher the mysteries of why children are similar to their parents. The broader, more global answer reminded everyone in the room how the way we think and talk about heredity has affected us all.
Like his interview, Zimmer’s book is deeply personal and broadly relevant. Zimmer approaches the topic from all angles. He writes about sequencing his personal genome and about his own family history, but also how sequencing genomes has taught society about our human migrations and the ways family pedigrees have taught us about diseases.
As a geneticist, I have more than average familiarity with a lot of what Zimmer covers in this book. And yet I learned far more than I expected—not just about Zimmer himself, but also about the roots of a scientific field I’ve been a part of for years. Roots of our society connect to the roots of genetics in ways that I never learned in Biology 101.
Did you know that Charlie Chaplin (the slapstick comedian you may know and love) brought the first paternity case based on blood tests to court? Or that the Russet Burbank potato (the potato that forms those McDonald’s French fries you may know and love) was the result of a genius plant breeder Luther “The Wizard of Horticulture” Burbank? Burbank didn’t really know what he was doing on a genetics level but he made a lot of money on potatoes anyway.
This is the magic in She Has Her Mother’s Laugh. Zimmer reels you in with well-known historical characters, his own life, and elements from his readers’ lives, connecting them seamlessly with the history of genetics. It’s a book that feels huge and all-encompassing, but often incredibly personal, too. After all, what is more personal than a genome?
Zimmer gets his own genome sequenced and describes the experience of having it analyzed as a bit of a letdown. If your genetic counselor doesn’t find anything of note in your genome, it’s probably a good thing—but maybe not very exciting. Perhaps luckily, Zimmer uses his own experience to tackle a huge, complicated, and controversial topic: race.
There’s no evidence supporting the concept of “biological race,” but the social concept of race (and of course, racism) certainly does exist. Zimmer describes the history of the human migration out of Africa as it is currently believed to have happened and connects it to the generations upon generations of people stretching back behind him towards “Y-chromosomal Adam” and “Mitochondrial Eve”—the earliest man and woman, respectively, that our DNA points us towards. This is just one of many examples where the tale of an individual’s experience (Zimmer getting his genetic data handed to him on a hard drive) morphs into the story of humanity.
Although the weight of my backpack with this book in it might suggest otherwise, reading She Has Her Mother’s Laugh never felt like a burden. It is a big, big book full of stories and facts, but it never feels dense. Zimmer writes with clarity and humor, and effortlessly connects the large to the small. If a family member or friend asks me why I think small, invisible things are so interesting, I’ll take all of the sticky notes out of this book, slide it across the table, and let them read it for themselves.