She Has Her Mother’s Laugh by Carl Zimmer

4 out of 5 stars

When people meet my children I often hear comments along the lines of; he is just like you, your daughter reminds me so much of your wife and similar comments. And it is true, their genetic inheritance comes directly from me and my wife and the blend of our genes has made three very different and unique children. What gets passed on and how is the subject of this weighty tome.

In this very researched book, Zimmer takes us back through our genetic history to show how these fragments make up our very being. Of the trillions of cells in our bodies, those that contain our DNA make us who we are, what we look like, how our health will be and countless other factors. But there is more to it than that, our genetic code is not the only thing passed from mother to child, echoes of past event from our father and his parents can be seen in the code, we get our first immune system via the placenta and the various microbes that ensure that we can live as passed on too.

There is a fascinating chapter on Chimeras – these are people who carry more than one set of DNA. This was never thought to be possible, but after various anomalies including where a mother was witnessed giving birth to a child, the DNA test said that it wasn’t her child. The investigation into it discovered how DNA can transfer between non-identical twins after one dies in the womb. A mother can even absorb some of the DNA from the child she is carrying.

There is a wealth of information and details in this substantial, but still a very readable book. Not only does he consider where we have got to in our understanding on DNA, but he contemplates the future of inheritance and what heredity will mean in years to come. Even though I never did biology while  at school, Zimmer manages to make this fairly substantial tome a straightforward book for readers like me.