Christian biologists were a small band in Dobzhansky's lifetime (even in America, where he spent much of his career), and he seems to have gone out of his way to downplay his religious beliefs on many occasions, saying only that he had a sort of nostalgia for the customs of his childhood. (Not only did he thus justify his religious practices to one of his colleagues, but he also invoked the same idea in his travel-writings when commenting on the attraction he felt to the life of some Greek hermits he met in Palestine.) When he did write on unavoidably religious topics for a public audience, he usually adopted a liberal and ecumenical tone, commenting on the incompleteness of human knowledge and the possibility that his own preference for Christianity was culturally conditioned. Even so, Dobzhansky's colleagues were puzzled by his spiritual interests, and frequently made note of them.
One may also note a decidedly Orthodox element in Dobzhansky's approach to science, and his emphasis (at a time when biological determinism was flourishing) on the ultimate freedom of the human being independently of genetics. For more on this remarkable thinker, see the essays in Mark B. Adams' collection The Evolution of Theodosius Dobzhansky, (Princeton, 1994).
Norman Hugh Redington