Ornithology, Evolution, and Philosophy 123

Ernst Mayr has been an observer all his life. At a young age, he became a naturalist
and learned to watch and intimately study the numerous kinds of birds inhabiting
the parks and rural surroundings of the cities where he grew up. As a boy, he ventured
into the fields, the forests, and along the lakes and streams nearly every free
minute possible, watching wildlife and observing the habits of birds, locating their
nests and, in some cases, following the hatching of their eggs. He thus developed
very early a general idea of what animal species are—sharply separated breeding
communities at particular localities, as he would say many years later, each with
particular ecological requirements for food and living space. Throughout his career,Mayrcontinuedtowatchbirdsandotheranimalsaswellastostudytheplants
in the areas where he lived and traveled (Lein 2005). He still made observations
even at the age of 100 on the birds around his home in Bedford, Massachusetts,
and followed the change of the seasons, longer than anyone who has ever lived. His
theorizing had a broad basis in his birdwatching activities during his youth and in
his later taxonomic studies. One has to be an observer, he said; if a person does not
observe and see what is going on in nature, then he or she has a good deal of difficulty
really understanding it. The term naturalist refers to a person who studies
plants or animals in a natural environment rather than in a laboratory. He or she
is a person who is “fascinated by biological diversity […] that excites our admiration
and our desire for knowledge, understanding, and preservation” (Futuyma
1998: 2). The evolutionary synthesis during the 1940s was a period when the mathematical
geneticists and the naturalists including paleontologists and systematists
began to speak the same language. All of the “architects” of this synthesis in North
America had been “young naturalists”, except the paleontologist G.G. Simpson.
As Mayr remarked, “this was Simpson’s handicap who never had a feeling for what
a species is.” The same is true for many philosophers, other paleontologists, and
even certain systematists. Mayr referred to them as “armchair naturalists” who
interpreted species either as constant, nonvariable entities of nature or as evolutionary
lineages because they had never watched and studied the animals or plants
in the areas where they had gone to school.