Biology Reference
In-Depth Information
face consisting of the plants, animals, and microorganisms interacting with
the physical factors of climate and geological processes; in other words,
each is “the whole ball of wax” for regions within which we as humans have
evolved and must exist. Examples are the tundra, prairie, savanna, desert,
deciduous forest, and rain forest. At the alpha level of research, the com-
plexity of organisms, the technologies used to study them, and the mas-
sive amounts of available information require specialization into myriad of
subdisciplines. Eventually, however, the data on plants and animals must
be integrated into a broader view of the biota. In turn, understanding how
biotas function and interact requires consideration of the climate and physi-
cal environment, and this raises the approach to the level of ecosystems.
The number of fossil fl oras and faunas studied in association with geologic
and climatic data, and interpreted in the context of global trends, now al-
lows the reconstruction of ecosystem history for several places and times
in North America and in some regions of tropical America. The number of
such sites in Latin America is increasing especially rapidly with continued
collaborative studies and particularly with new projects by student and resi-
dent scientists. A measure of the progress being made is that it is now pos-
sible to predict with some accuracy the type of paleocommunity likely to
be present given the locality and the age of the deposits. This suggests that
the database is adequate to provide a context for assessing environmental
interpretations made from individual assemblages. A broad level of predict-
ability also certifi es the overall reliability of the various methods being used
to reconstruct ecosystems.
Another assumption, emerging from my own fi fty years of fascination
with the natural history of the New World, is that understanding present-
day ecosystems must include the concept of time. It is possible to gain
some understanding of the biological world by describing sequences of fos-
sil fl oras and faunas, or by studying the taxonomy, distribution, ecology, and
processes operating within and between extant organisms and communi-
ties. However, the fullest understanding of this world, its origin, current
status, trends, and future will come from the seamless integration of neobi-
ology with paleobiology, and a knowledge of the environmental dynamics
that drive the processes of change. Like an Annie Leibovitz photograph that
captures more than the moment, modern ecosystems provide a snapshot of
a scene that is a composite of all events bearing upon its subjects over the
years. The importance of time in assembling broad unifying summaries in
biology was early demonstrated by Charles Lyell's contribution to Charles
Darwin's thinking on evolution. A geologist, Lyell brought to the conscious
forefront of Darwin's thoughts an image of species projecting back into the
