The enormous recent success of molecular developmental biology has
yielded a vast amount of new information on the details of development.
So much so that we risk losing sight of the underlying principles that
apply to all development. To cut through this thicket, John Tyler Bonner
ponders a moment in evolution when development was at its most
basic--the moment when signaling between cells began. Although
multicellularity arose numerous times, most of those events happened
many millions of years ago. Many of the details of development that we
see today, even in simple organisms, accrued over a long evolutionary
timeline, and the initial events are obscured. The relatively
uncomplicated and easy-to-grow cellular slime molds offer a unique
opportunity to analyze development at a primitive stage and perhaps gain
insight into how early multicellular development might have started.
Through slime molds, Bonner seeks a picture of the first elements of
communication between cells. He asks what we have learned by looking at
their developmental biology, including recent advances in our molecular
understanding of the process. He then asks what is the most elementary
way that polarity and pattern formation can be achieved. To find the
answer, he uses models, including mathematical ones, to generate
insights into how cell-to-cell cooperation might have originated.
Students and scholars in the blossoming field of the evolution of
development, as well as evolutionary biologists generally, will be
interested in what Bonner has to say about the origins of multicellular
development--and thus of the astounding biological complexity we now
observe--and how best to study it.
