Jerry A. Coyne Books

To build a coherent theory of speciation, we must first define what a species actually is. Throughout biology’s history, this deceptively simple question has sparked intense debate. The viewpoint that I, following Ernst Mayr, find most fruitful is the *biological species concept*: species are groups...

From Speciation

Every instance of speciation begins with populations that once exchanged genes freely but now cannot. The transition from shared gene flow to reproductive isolation defines the birth of a new species. But isolation is not a monolithic barrier; it is composed of layered mechanisms that act before and...

From Speciation

Stone remembers what human memory cannot. One of Coyne’s strongest points is that the fossil record preserves a chronological history of life, allowing us to see not just what existed, but when it existed and how major groups changed through time. Fossils do not appear randomly in rock layers. Simpl...

From Why Evolution Is True

To watch an embryo develop is to witness history hidden inside growth. Coyne shows that embryology provides powerful evidence for evolution because organisms that look very different as adults often resemble one another strikingly in early development. These similarities are not accidental. They ref...

From Why Evolution Is True

Location tells a story that anatomy alone cannot. Coyne uses biogeography—the geographic distribution of species—to show that life’s diversity reflects descent, migration, and isolation rather than independent creation. Species are not scattered across the globe wherever conditions happen to suit th...

From Why Evolution Is True

Evolution is often dismissed as too slow to witness, yet Coyne emphasizes that natural selection can be seen in real time. Selection occurs whenever individuals differ, those differences are heritable, and some variants leave more offspring than others. Given enough generations, populations change. ...

From Why Evolution Is True