- "Clearly worth attention...Costa makes use of his experience as a field naturalist and his knowledge of the modern literature of evolutionary biology to illumine many passages in Darwin's work."
- —New York Review of Books
- "Despite being 150 years old, The Origin is a living text for biologists. It is full of unsurpassed natural history observations, a model of careful scientific argument that still can catch the imagination with the grandeur of the views it puts forward. Jim Costa has provided an exceptionally lucid explanation."
- —Janet Browne, author of Charles Darwin: The Power of Place
- "Costa does a wonderful job of annotating Darwin's groundbreaking classic On the Origin of Species. In more than 900 notes, he explains, expands, contextualizes and updates much of what Darwin had to say about evolution and its causes...Costa's thoughtful and informative notes enable readers to gain a much fuller appreciation for Darwin's genius and breadth of knowledge—a fine tribute in the great scientist's bicentennial year."
- —Publishers Weekly
- "On the Origin of Species has too long been one of those worthy books whose fate is to be lauded but unread. Jim Costa's deft commentary—an authoritative and engaging mix of history and science—will change that. The Origin is forbidding and inaccessible no longer—it has evolved! The Annotated Origin of Species restores, for modern readers, the freshness and excitement that made it a bestseller when it first appeared. Charles Darwin, I'm sure, couldn't wish for a better 200th birthday present."
- —Andrew Berry, editor of Infinite Tropics, An Alfred Russel Wallace Anthology
