How birds evolved examined in new book

"All species of birds have evolved from a single ancestral species, which was one of a great many species of vertebrates that all evolved from a single, more ancient, common ancestor; this, in turn, was a descendant of the ur-ancestor of all animals, from sponges to primates.

"And so every feature of every bird, from its DNA sequences to its behaviors, has come into existence — has evolved — during this history of descent."

Author Douglas J. Futuyma tells us this in the opening pages of his book "How Birds Evolve: What Science Reveals about Their Origin, Lives, and Diversity."

If you have "why" questions about bird colors, forms and behavior, Futuyma answers them for you in this very complete, very detailed presentation of the evolutionary process.

Princeton University Press, hard cover, 269 pages, illustrated, index, and extensive bibliography, $29.95.

Bird photographs are very popular these days. Photos from an annual competition "Bird Photographer of the Year" are now in a book with the same title. Entries and winners in several categories are included. Published by Harper­Collins, in bookstores now for $31.99.