Book Review: She Has Her Mother's Laugh

I do, in fact, have my mother's laugh. Moreover, when listening to a message I had left on our home answering machine, I recently discovered that I have my sister's voice. Of course, when I hear myself normally, the hum of my vocal chords sounds far different to my ear, but there it was, blaring out through the machine, the sound of my sister's voice and I knew it was me. I was startled. My sister and I are, in many ways, carbon opposites. She is dark-complected while I am fair. She is taller, trendier, more driven, and more extravagant. Yet, if you look at this photo snapped at her wedding, you can see that, despite our many differences, we still resemble one another quite a bit:

That is the beauty of heredity. We share the same genetic foundation and you can tell that we are related. But, heredity is quite a mixed bag. I may be happy my mother passed along her wit and intelligence, but will I be happy if she passes along her dementia, as well? Carl Zimmer's book, She Has Her Mother's Laugh: The Powers, Perversions, and Potential of Heredity is a weighty tome exploring these concepts. (Indeed, if it weren't for my passionate curiosity about genetics and eugenics, I might have left the hefty book on the shelf. 574 pages is quite an investment when your reading mojo is flagging.) But the writing is easy to understand and follow and the subject is fascinating.

I devoured the history of our understanding of heredity and recognized anew its influence on social, political, and economic aspects of life. Every single page seemed to hold something fresh to discover and digest. I hadn't known that Pearl S. Buck had a mentally-challenged daughter (who was later diagnosed with PKU) and that her need for funds to institutionalize this child drove her writing. I learned about freemartin cows and was further intrigued by tetragametic chimeras and how such individuals might not bear the same DNA as their offspring, despite being able to prove they gave birth to them.

As the book went further into visions of the future, my concerns and hesitations multiplied. Things like preimplantation genetic diagnosis, genetic engineering, experiments in mutagenic chain reactions (splicing in artificial DNA to trick the host into copying new genetic patterns), and the ethical questions of releasing such genetically altered organisms into our world all made the hair stand up at the back of my neck. Will we one day live in a world where couples with means will be able to tailor-make their children to their specifications (enjoying genetically enhanced intelligence and health)? Will our attempts to eradicate genetic diseases eliminate the diversity of humanity? Will desires to crush malaria induce scientists to release genetically-modified mosquitoes that will eventually alter something in our ecosystem or food chain? Who knows?

Zimmer presents lots of mental fodder. If you don't buy into evolutionary theories, his discussions might annoy at times, but he still offers up a gigantic mass of information and knowledge about the subject of heredity. Plus, he does so in easy-to-consume, bite-sized pieces so the new knowledge is absorbed effortlessly. Indeed, the inside cover declares that the book reads like a novel. It clearly has a story-teller's structure. So, don't let the heft discourage you. As we enter this brave new world of technological and scientific advances, you will want to be forewarned and forearmed. Heredity, as we know it, is changing every day. This book explains the history and the potential future with gravity and clarity.