Comparative Parasitology 67(1) 2000 - Peru State College

(Hoberg et al., 2000). These studies indicate the
necessity for having detailed phylogenetic and
ecological data as the basis for examining patterns
and process in speciation for hosts and parasites
and at a higher level for evaluation of faunal
and community history.
Parasites—paradigm systems for studies of
community structure and evolution:
One major advantage of parasite communities
over others is that the habitat they live in, the
host, has such a well defined structure. . .The host
microcosm is replicated through time and space
much more so than habitats for most other organisms.
Therefore, the study of comparative
community structure is very powerful. (Price,
1986)
There is, as yet, little overlap between parasite
groups for which we have extensive community
ecological information and groups for which we
have extensive phylogenetic information (Poulin,
1995a, 1997b). In addition, differences in
understanding between systematists and ecologists
about the use of phylogenetic methods and
the possible forms of phylogenetic components
in community structure have led to unproductive
and inappropriate polarization of perspectives
(Bush et al., 1990). Perspectives on the primacy
of ecological versus phylogenetic-historical determinants
of faunal structure are changing,
however, as researchers begin to recognize that
communities are mosaics of species that evolved
elsewhere and dispersed into the area (colonizers)
and species that evolved in situ (residents
or endemics) (Aho and Bush, 1993). Each parasite
community represents a historically unique
combination of colonizers and endemic species,
in terms of both geographic dispersal and host
switching (Brooks and McLennan, 1991, 1993a,
1993b, 1993c; Hoberg, 1997a). Because parasite
communities are so well defined and so easily
studied, parasitologists have an opportunity to
assume a leadership role in the study of community
evolution.
Parasites are developmentally and ecologically
complex organisms subject to and constrained
by the same rules that govern the evolution of
all biological systems (Poulin, 1995b). This is
the key to their value in predictive studies. Ernst
Mayr (1957) recognized nearly half a century
ago that the study of parasites "is not only valuable
for the parasitologist, but is also a potential
gold-mine for the evolutionist and general biologist."
BROOKS AND HOBERG—PARASITE BIODIVERSITY 17
Here at the end of the twentieth century, and
in the midst of the biodiversity crisis, those sentiments
are truer than ever. The ability to distinguish
evolutionary colonizers from residents
will permit us to recognize introduced species
and to assess the risk that they may cause emergent
diseases. The ability to distinguish evolutionary
generalists from specialists will enable
us to assess more fully the extent of biocontainment
for any parasite being used as a biocontrol
agent. Finally, the ability to distinguish the old
from the recent components of ecosystem structure
will help us assess what species are likely
to respond to anthropogenic changes, in what
order, in what ways, and to what extent.
GTI Component 3—Management of Systematic
Knowledge Bases: Getting the Information
to Those Who Can Use it Effectively.
DIVERSITAS estimates that within 5 years
electronic data handling and interlinked knowledge
systems will become the principal medium
for all activities associated with applying systematic
information to biodiversity studies and
policies. These efforts will require large databases
on taxonomic information, specimens, and
data in collections.
The taxasphere can contribute substantially in
this area by developing 2 types of home pages:
(1) phylogenetic home pages, providing the
most up-to-date phylogenetic trees for all groups
of parasites, interconnected in such a way that
anyone can move from one taxonomic level to
another (this will provide the predictive framework
within which a variety of specialists can
operate), and (2) species home pages, providing
the following information for each targeted species:
(i) what is it (and how to distinguish it from
others), (ii) where is it, and (iii) what is its natural
history. This process has been termed the
creation of a biodiversity Yellow Pages for the
Internet (Janzen and Hallwachs, 1994). These
home pages will include electronic images,
which can be used for other purposes, such as
taxonomic descriptions and revisions or identification
guides. These home pages would also
include information about the known natural history
of each species. Species home pages should
be cross-linked to phylogenetics home pages so
that we will eventually have a complete listing
of the phylogenetic relationships of all species
linked to their natural histories. Biodiversity information,
irrespective of format, must eventu-
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