As she grows into adulthood, only a few of her eggs mature, are released into the oviduct, and are fertilized by sperm stored from copulation that took place days or weeks earlier. Within a matter of hours, the fragile yolk is surrounded by albumen and the whole is gradually encased within a turquoise jewel of a shell. Soon afterward the fully formed egg is expelled onto a bare rocky ledge, where it will be incubated for four weeks before another chick emerges and the life cycle begins again. The Most Perfect Thing is about how eggs in general are made, fertilized, developed, and hatched. The eggs of most birds spend just 24 hours in the oviduct; however, that journey takes 48 hours in cuckoos, which surreptitiously lay their eggs in the nests of other birds. From the earliest times, the study of birds' ovaries and ova (eggs) played a vital role in the quest to unravel the mysteries of fertilization and embryo development in humans. Birkhead uses birds' eggs as wondrous portals into natural history, enlivened by the stories of naturalists and scientists, including Birkhead and his students, whose discoveries have advanced current scientific knowledge of reproduction.

    What is the psychological mechanism that allows us to know something is true but act as if it is not? George Marshall’s search for the answers brings him face to face with Nobel Prize–winning psychologists and Texas Tea Party activists; the world’s leading climate scientists and those who denounce them; liberal environmentalists and conservative evangelicals. What he discovers is that our values, assumptions, and prejudices can take on lives of their own, gaining authority as they are shared, dividing people in their wake.With engaging stories and drawing on years of his own research, Marshall argues that the answers do not lie in the things that make us different, but rather in what we share: how our human brains are wired—our evolutionary origins, our perceptions of threats, our cognitive blind spots, our love of storytelling, our fear of death, and our deepest instincts to defend our family and tribe. Once we understand what excites, threatens, and motivates us, we can rethink climate change, for it is not an impossible problem. Rather, we can halt it if we make it our common purpose and common ground. In the end, Don’t Even Think About It is both about climate change and about the qualities that make us human and how we can deal with the greatest challenge we have ever faced.