 Whitman, Edmund Beecher Wilson, and others at the Marine Biological Laboratory in Woods Hole, Massachusetts, dedicated considerable energy to discovering the nature of each cell and its internal organization and relationships, in an attempt to discover the relative contributions of preformation and epigenetic development to a materialistic explanation of development. By the early twentieth century, they had moved toward an understanding that included a fertilized egg that was to some extent preorganized and differentiated, including in the nuclear chromosomes, and also a capacity of the individual organism to respond to changes in its environment or to self-regulate. This was epigenesis allowing some minimal predeterminism.