Edward O. Wilson, the pioneering Harvard biologist who argued for a new vision of human nature in “Sociobiology” and warned against the decline of ecosystems, has died. Wilson died on Dec. 26 in Burlington, Massachusetts, according to an announcement posted Monday on the E.O. Wilson Biodiversity Foundation’s website. The professor and two-time Pulitzer Prize-winning author first gained widespread attention for his 1975 book, “Sociobiology: The New Synthesis,” in which he spelled out the evidence suggesting a link between human behavior and genetics.