This Week's Citation Classic

This week there are actually two citation classics, both published in 1961.

Connell JH. 1961. The influence of interspecific competition and other factors on the distribution of the barnacle chthamalus stellatus. Ecology 42: 710-723.

Connell JH. 1961. Effects of competition, predation by Thais lapillus, and other factors on natural populations of the barnacle Balanus balanoides. Ecological Monographs 31: 61-104.

According to the ISI Web of Knowledge, they have been cited 888 and 593 times respectively, which for Ecology papers, is a considerable sum. Both of these papers result from Joseph Connell's Ph.D. work at Glasgow University.

Connell, fresh from a frustrating M.S. project on rabbits in the Berkeley hills (he was able to capture only 40 rabbits in two years, one of them 19 times), "vowed then to adopt a simple rule of thumb, namely, never again to study anything bigger than [his] thumb."

Inspired by an obscure paper by the French Ecologist Harry Hatton, Connell decided to expand on Hatton's work intertidal invertebrates, particularly on the effects of predation and competition for space. The data Connell was able to collect has significant implications for the study of interspecific competition, recruitment, predation and population dynamics, but their importance transcends their direct scientific relevance. His work can be pointed to as the birth of a major paradigm change in the study of Ecology, the origin of controlled experimental manipulations of natural populations in the field. Although it is almost stunning to consider today, Ecologists, at one point, conducted mainly observational studies, and almost never engaged in direct experimental manipulations.

As Connell said, "Most scientists regard the experimental method as the normal way to do scientific research. But many ecologists still don't do experiments, possibly because they associate them with white coats and indoor laboratories. I did too until I was led by Ed Deevey's review to a paper by a little known French Ecologist, Harry Hatton, who in the 1930s performed a beautiful series of experiments on natural populations of marine animals and plants."

Another interesting thing regarding the Chthamalus stellatus work is that it was a side project from Connell's main dissertation work. In fact, Connell explicitly disregarded a suggestion by his major professor CM Yonge not to spread his study wider. However, since Yonge was in Glasgow and Connell was out of sight on the Isle of Cumbrae, Connell could safely ignore his major professor's instructions and embark on a secret study of interspecific competition.

Deevey ES. 1947. Life tables for natural populations of animals. Quart. Rev. Biol. 22: 283-314.
Hatton H. Essais de bionomie explicative sur quelques especes intercotidales d'algues et d'animaux. Ann. Inst. Oceanogr. Monaco 17: 241-348.

Photo by Brian Teusch.