Pianka, E. R. 2002. A general review of zoological trends during the 20th century. A. Legakis, S. Sfenthourakis, R. Polymeni, and M. Thessalou-Legaki, eds. Proc. 18th International Congress of Zoology, pp.3-13. Opening address at the 18th International Congress of Zoology, Athens 2001. Download pdf


Enormous progress has been made in zoology during the 20th century, largely due to a multitude of clever new technological advances: electron micrographs, oscilloscopes, radioisotopes, radiotelemetry, digital and satellite imagery, PCR and DNA sequencing, global positioning systems (GPS), rapid travel, unimaginable computing prowess, faxes and email. All this new technology has allowed zoologists to study things previously impossible. The century began with the rediscovery of Mendelian genetics, followed by the discovery of DNA structure, the genetic code itself, instinct and animal behavior, speciation, hybrids, parthenoforms, a new previously unknown Kingdom of chemosynthetic organisms, restriction enzymes, cloning, genetic engineering, genetic control of development, and understanding of metabolic pathways.

One of the strongest recurrent themes in biology this century has been to consider all sorts of phenomena within the context of natural selection. Phylogenetic systematics has revitalized many areas of biology, forcing and facilitating an evolutionary approach. Evolution provides the conceptual backbone of zoology. Zoologists study phenomena that range across vastly different spatial and temporal scales, from molecules to cells to organisms to populations to communities and entire ecosystems.

Like other scientists, most zoologists have rushed to embrace the reductionistic approach. Too often, workers at different levels look somewhat askance at the next higher level of approach. The reason for this hesitancy to accept the next higher level may be that one must slur over interesting detail at one's own level in order to practice biology at the next level up. Each level of approach offers distinct advantages but suffers from its own problems. Molecular biologists cannot "see" the objects of their studies, but they can do experiments in Ependorff tubes in small spaces in a matter of hours. An experiment is planned before lunch, executed that afternoon and results are analyzed that evening or the next day. Rapid progress can be made with such a compressed timetable. Other sorts of biology require more space and greater patience. Funding for zoological research is strongly skewed towards molecular biology. We should all attempt to couple our approach to higher levels and we should be more tolerant of others working at higher levels of approach. Funding should be spread more equitably across disciplines. We have made impressive strides in understanding phenomena at most levels of approach in biology, but the approach at the community-ecosystem level lags far behind others. Much more thought needs to be devoted towards attempts to connect community properties with those of individuals in populations. Examples of how community-level properties could emerge from attributes of individuals are given.