She Has Her Mother’s Laugh by Carl Zimmer; Genetics in the Madhouse by Theodore Porter – review

Two new studies of heredity expose bizarre anomalies – and popular myths – in our understanding of genes

Lydia Fairchild was 27 when she became pregnant with her fourth child in 2003. In order to apply for welfare, recent legislation in the US state of Washington required her to prove that her children were genetically related to her and their father, Jamie. So she took a DNA test. But while the results showed that Jamie was indeed the father of her first three children, there was no match to prove she was their mother. This was a shock to Fairchild, who had distinct memories of giving birth to them.

State officials, suspecting a welfare scam, warned her that her children would be taken away from her. And when she eventually had her fourth child – the birth witnessed by a court official – again a blood sample showed the baby ...