This painting is from the book Evolution: The Triumph of an Idea by Carl Zimmer. The artist was Laura Hartman Maestro. The book is a companion to the PBS series of  The Evolution Project, a coproduction of the WGNH/NOVA science unit and
Clear  Blue  Sky  Productions.
Visit the extensive website
for this production.

Caption from the book:

The range of gulls forms a ring
around the North Pole. Within the
ring, neighboring birds can mate with each other, even though they look slightly different. But the birds at the two ends of the ring -- the Herring Gull and Lesser Black-backed Gull -- are so distinct that they can't mate with each other although they live side by side. Ring species are some of the best evidence for how new species evolve.

Back to the Living Transitionals Page