Biology Reference
In-Depth Information
where the parameters of a model are systematically varied throughout
plausible ranges and general behavioral features of the system are ex-
plored, an ensemble-modeling approach.
Directed graphs have been used to study complex systems that can
be expressed as networks. It is easy to imagine a honey bee colony as a
network of individuals, each making independent decisions based on
local information processed through a brain of 900,000 neurons that
has been programmed by development and experience. No single in-
dividual has complete information about the current state or history
of the colony, but collectively the 30,000 individuals with 900,000
neurons each (a total of about 27 billion neurons, less than half the
number in a human brain) are capable of storing an enormous amount
of information about the hive and foraging environments. Individual
workers share a limited amount of information with their nestmates.
Usually this is shared indirectly through their behavioral activities,
but some information is shared directly through an intricate commu-
nication system involving chemicals (such as pheromones), shared
food, and their recruitment behavior—called the dance language of
the bee.
Sandra Mitchell and I used a directed-graph-network, ensemble-
modeling approach to explore the origins of division of labor. In early
1989, I was invited to be the token biologist in the philosophy of biology
symposium at the biennial meeting of the Philosophical Society of
America, held in 1990. h e symposium featured philosophers and his-
torians who were familiar with the work of Stuart Kauf man (Kauf -
man was trained in philosophy as an undergraduate) and who could
especially comment on his new topic
h e Origins of Order.
Kauf man
used ensemble modeling and directed graphs to model gene regulation
in the 1970s. I was asked to read a drat of his manuscript and see
whether I found his topic to be of any value to me, a biologist, in looking
at the level of social organization. I agreed and immediately called my
good friend Sandra Mitchell, a philosopher of biology and an acquain-
tance of Kauf man's, and asked her to help me. I needed help because I
had no idea what to expect from philosophers. She agreed, and we went
to work building a model.
