Introduction. The evolution of evo-devo biology.

Abstract

Once seen as distinct, yet complementary disciplines, developmental biology and evolutionary studies have recently merged into an exciting and fruitful relationship. The official union occurred in 1999 when evolutionary developmental biology, or “evo-devo,” was granted its own division in the Society for Integrative and Comparative Biology (SICB). It was natural for evolutionary biologists and developmental biologists to find common ground. Evolutionary biologists seek to understand how organisms evolve and change their shape and form. The roots of these changes are found in the developmental mechanisms that control body shape and form. Developmental biologists try to understand how alterations in gene expression and function lead to changes in body shape and pattern. So although SICB only recently validated evo-devo as an independent research area, evo-devo really started over a decade ago when biologists began using an individual organism's developmental gene expression patterns to explain how groups of organisms evolved. To highlight this emerging field, the PNAS Editorial Board has sponsored a special feature on Evolutionary Developmental Biology. This evo-devo special feature contains eight Perspective articles and a review that examine evo-devo's progress to date, as well as 15 research articles that add new information and focus on the most recent evo-devo biology trends. The majority of the research articles were submitted directly to the PNAS office through our Track II system, and were evaluated by an Editorial Board member. After the initial screening, papers were assigned to an Academy Member-editor who oversaw a process where research manuscripts were rigorously peer-reviewed by experts in the field. The basis for all evo-devo research covered in this issue is, arguably, the Cambrian “explosion.” This explosion occurred approximately 550 million years ago and lasted only 45 million years. This “brief” period in history resulted …