This is the first of what we hope to be a long series of Volvox meetings to be held every other year, alternating with the Chlamy meeting. The idea of a meeting on everything about Volvox and its relatives (aka Volvocales or volvocine algae; see http://www.unbf.ca/vip/) reflects both an increase in the size of the Volvox community and the realization that many researchers from fields traditionally not associated with Volvox research (e.g., physics, theoretical biology) are interested in various aspects of the system. Indeed, volvocine algae have become an important model system for the evolution of multicellularity, development and cellular differentiation, and lately have yielded important results in fields as diverse as genomics, hydrodynamics, and social evolution. We hope that such a meeting will foster exchange of ideas and expertise, and will initiate new collaborations. Furthermore, with these meeting we wish to attract new people and to build a stronger Volvox community.

(1) They comprise a group of closely related organisms that range in complexity from unicellular forms, undifferentiated colonies, to true multicellular individuals with completely differentiated germ and somatic cells.

(2)  They are of such recent origin (in geological time) that there is hope that its various members may still retain within their genomes traces of the genetic changes that permitted transitions from one level of organizational complexity to the next.

(3) The transitions in complexity have occurred more than once, thus raising the hope that the genetic changes and selective factors required for these transitions may be analyzed.

(4) They have been studied in detail by cytologists, biochemists, developmental biologists, geneticists, and molecular biologists.

(5) Their distribution, natural history, and ecology has been extensively studied.

(6) They can easily be obtained from nature and maintained in the lab under realistic growing conditions that allow for an eco-physiological framework.

(7) The facultative sexual cycle is well characterized.

(8) The genomes of two representatives - the unicellular Chlamydomonas reinhardtii  and the multicellualr Volvox carteri - have been sequenced.

(9) Several social genes (regA, glsA) underlying germ-soma separation and fitness reorganization have been identified.

(10) Stable mutant forms of V. carteri with disrupted germ-soma separation have been isolated.