This book is about how people and greyhounds co-evolved in England between 1200 and 1900. Co-evolution means change in the frequency of traits for two or more populations interacting with each other, traits being defined as both physical and behavioral. Humans changed the traits of greyhounds through breeding, and human traits changed in response. Russell uses this case study to make a larger argument—that evolution is integral to history. Historical change in human society is evolution, and historical forces are evolutionary forces for humans and other species.
It is often easier to understand how humans change animals than vice versa. Russell employs the biological concept of niche, defined as a job–habitat combination, to explain how co-evolution occurs. “Niches have evolutionary consequences. Every niche rewards a different combination of traits” (3). Greyhounds were bred for niches—to do certain jobs within certain habitats. As niches changed, different physical and behavioral traits...