In this thought-provoking book, award-winning New York Times columnist and science writer Carl Zimmer presents a history of our understanding of heredity, in a wide-ranging, ambitious and original investigation of a force that has crucially shaped human society - and is set shape our future even more radically. She Has Her Mother's Laugh presents a profoundly original perspective on what it is that we pass along from generation to generation. Charles Darwin played a crucial part in turning heredity into a scientific question, and yet, for all his achievements, he failed spectacularly to answer it. In the early twentieth century, the birth of modern genetics seemed to do precisely that. Gradually, we came to translate old notions about heredity into a language of genes. As the technology for studying genes has become cheaper, millions of ordinary people have ordered genetic tests to link themselves to missing parents, to distant ancestors, to ethnic identities .Yet, as Zimmer writes, 'Each of us carries an amalgam of fragments of DNA, stitched together from some of our many ancestors. Each piece has its own ancestry, traveling a different path back through human history.

A particular fragment may sometimes be cause for worry, but most of our DNA influences who we are--our appearance, our height, our penchants--in inconceivably subtle ways'.Heredity isn't a simple matter of genes that pass from parent to child. Heredity continues within our own bodies, as a single cell gives rise to the trillions that make up an adult. We say we inherit genes from our ancestors - using a word that once specifically referred to kingdoms and aristocratic estates - but we also inherit other things that matter as much or more to our lives, from microbes to the technologies we use to make life more comfortable. We need a new - broader-ranging - definition of what heredity is and, through Carl Zimmer's lucid exposition and storytelling, this tour de force of science writing delivers it.Weaving historical and current scientific research, original reporting and his own experience as the father of two daughters, Zimmer ultimately unpacks the urgent ethical quandaries that arise from new biomedical technologies, but also long-standing presumptions about who we really are and what it is that we can pass on to future generations.