The study of formal ecology nowadays does not only handle many concepts where the biologists started to be entangled with the ideas about how nature relates. Besides it is not a series of preservationist mottos, which must be used to preserve our environment as a fair or not fair claim. The academic ecology of the XXI century is philosophy and pure mathematics trying to reorganize theories and hypotheses, which explain the millionaire universe of biodiversity. Moreover, all of that is due to one man: Dad MacArthur, as my professors with affect and respect name him.

Truly, the grandfather of ecology must be the German naturalist and medic Ernst Haeckel (1834-1919), who coined the term “ecology” from the Greek oikos (which means home) and logos (word, measure, study…). Then ecology means our environment, our region and even the planet. The book of Haeckel was an illustrated text with the plethora of biodiversity known by those days from micro to macro organisms. Entitled Kuntsformen der Nature, perhaps the book had to be inspired by the Art Noveau of the final years of the 1800s. In that XIX century and the former XVIII, naturalists dedicated almost exclusively, and with deserved reason, to understand each species, how they are, function and reproduce. These early studies of the living things drove to the Theory of Evolution by Natural Selection proposed by the famous Englishman Charles Darwin (1809-1882). Darwin and his theories inspired Haeckel... and many more scientists around the world.

Nevertheless, it was not until the beginning of the year 1910 when the first ecologists started to dig deep regarding how the species relate to each other and his environment. Right now it is a mantra to say that the real father of modern ecology is George Evelyn Hutchinson (1903-1991) This British biologist, earned the National Science Medal of the United States, the nation where he made most of his achievements, and is the author of the majority of theorems and equations that rule the interactions among all living things.

However, a pupil of Dr. G.E. Hutchinson at the Yale University was destined to bright as much as his mentor. This young man born in April 1930 in Canada but was raised in southern Vermont. Very skinny, mid high, shy on his temper and way of talk, besides these he was good looking as his colleagues describe him and the pictures show. His name was Robert MacArthur. Bob had outstanding teachers, starting from his mother, a bacteriologist. His father was a professor of Genetics at the University of Toronto, and finally an excellent High school teacher of mathematics, Allan Paine. In addition, the woods and prairies of Canada, and in the town of Marlboro in the USA where he walked, must have inspired him the love for nature. Also, to try to answer which laws, rule it.

In the year 1953, Bob received his master's degree in Mathematics with the highest honors at Brown University. Then he pursued a doctorate in Biology at Yale University. His doctoral thesis in 1958 was something really innovator, Bob study five species of birds call warblers (Dendroica spp). His question and the question that had ecologist community spinning was: What factors control the abundance of species and avoid extinction meanwhile they are competing with each other’s?

The way he aboard the dilemma was very simple, but transcendent. Moreover, this adds another ecological paradox regarding the concept of niche (function/habitat). It means the role played by each species in its community, and raised another question: How five different species of warblers share the same niche?

The answer that MacArthur was looking for lead him to follow the behavior of each warbler’s species on the North American conifers. In a similar way that Darwin’s finches of the Galapagos Islands gave origin to new species by natural selection, MacArthur realized that each warbler does not compete by the resources of the pines. Different species had similar niches that can coexist on different sites even at the same tree. Bob went farther when he used mathematics for the coexistence relation. In the second decade of the XX century, several European scientists’ derived equations for the “struggle of existence” as the famous Russian ecologist Georgi Gause proposed. MacArthur’s formulas afterward with the “broken stick” and limiting similarity models showed that the sharing of resources is possible, and the competitive exclusion not always occurs.

In the meantime, as Bob studies happened, he got married to Elizabeth Bayles Whittemore, they had one daughter and three boys. From his familiar life, we know that he dedicated most part of his daily work at home to them. After graduating from Yale, he found a job, as an Assistant Professor at the University of Pennsylvania where he reached the highest rank in 1965. For his paper about the warblers, MacArthur received the Mercer Prize of the American Ecological Society. Bob said, not everything is mathematic; there is also the search for art (as in Ernst Haeckel’s case). Nevertheless, the most important, is looking for patterns that repeat and need explanations.

On a trip, he made on a ship, and always observing birds, he realized the pattern of abundance of the same birds between the continent and the islands. This obvious distribution for the common people, but not for him, lead Bob to write with the entomologist Edward O. Wilson the book The Theory of Island Biogeography in 1967, a text of profound influence in the ecological science. Two years later, he was elected member of the National Academy of Science of the United States of America.

From the University of Pennsylvania went to the famous Princeton in 1971, working there he discovered that he had terminal kidney cancer. Knowing he had less than a year of life, he spent it writing his second book Geographical Ecology. He worked even at bed to complete the text, and his coauthor helped him. Robert MacArthur passed away on the first day of November 1971 in New Jersey at 42 years of age. Besides his family, he left an outstanding legacy for biological studies. He wrote 51 scientific articles, also left friends, colleagues, and pupils who follow his researches with famous names like Levin, Rozensweigh, Fretwell, Pianka, May, Lack, Connell, and of course his tutor Hutchinson.


Fretwell, S. 1975. “The impact of Robert MacArthur in Ecology”. Ann. Rev. Ecol. Syst. 6:1-13.
MacArthur, R. H. 1958. “Population ecology of some warblers of northeastern coniferous forests”. Ecology 39:599- 619.
Toomey, D. 2013. “A Search for Patterns: The Life of Robert MacArthur”. Potash Hill, 9:2-7.
Wilson, E. & G.E. Hutchinson. 1989. “Robert Helmer MacArthur. A biographical memoir”. Proc. Nat. Acad. Sci., 11pp.