People often grow personal gardens, hoping for a handful of vegetables after a summer of work. And yet, with his own garden, a man with little biology training and severe test anxiety discovered the rules which govern plant, animal and human inheritance. Many think of Gregor Mendel as the monk-creator of tedious high school biology lectures on pea plant whatever. But the reasons Mendel worked for eight long years in a tiny monastery garden to discover the rules of heredity, rules that ultimately supported Darwin’s Theory of Evolution, are surprising.

But why does genetics “work”? We’ll discuss Mendel’s motivations, illustrate why meiosis (sex!) and Mendel are the same thing, and teach you how to follow your own inherited traits. (Can you roll your tongue? Do you have hairy knuckles? Did mom have an affair with the mailman?)

Her name was Henrietta Lacks, but scientists know her as HeLa. She was a poor Southern tobacco farmer who worked the same land as her slave ancestors, yet her cells—taken without her knowledge—became one of the most important tools in medicine. The first “immortal” human cells grown in culture, they are still alive today, though she has been dead for more than sixty years. If you could pile all HeLa cells ever grown onto a scale, they’d weigh more than 50 million metric tons—as much as a hundred Empire State Buildings. HeLa cells were vital for developing the polio vaccine; uncovered secrets of cancer, viruses, and the effects of the atom bomb; helped lead to important advances like in vitro fertilization, cloning, and gene mapping; and have been bought and sold by the billions.

In Galileo’s Daughter, Dava Sobel tells the story of the famous scientist and his illegitimate daughter, Sister Maria Celeste. Sobel bases her book on 124 surviving letters to the scientist from the nun, whom Galileo described as “a woman of exquisite mind, singular goodness, and tenderly attached to me.”