Helen of Troy refuge with Leda. The swan gained her affection, and the two mated. Leda then produced an egg, from which Helen emerged. The First Vatican Mythographer introduces the notion that two eggs came from the union: one containing Castor and Pollux; one with Helen and Clytemnestra. Nevertheless, the same author earlier states that Helen, Castor and Pollux were produced from a single egg. Pseudo-Apollodorus states that Leda had intercourse with both Zeus and Tyndareus the night she conceived Helen. On the other hand, in the "Cypria", part of the Epic Cycle, Helen was the daughter of Zeus and the goddess Nemesis.
Leda Cosmides Leda Cosmides Leda Cosmides (born May 1957 in Philadelphia, Pennsylvania) is an American psychologist, who, together with anthropologist husband John Tooby, helped develop the field of evolutionary psychology. Cosmides originally studied biology at Radcliffe College/Harvard University, receiving her BA in 1979. While an undergraduate, she was influenced by the renowned evolutionary biologist Robert L. Trivers, who was her advisor. In 1985, Cosmides received a PhD in cognitive psychology from Harvard. After completing postdoctoral work under Roger Shepard at Stanford University, she joined the faculty of the University of California, Santa Barbara in 1991, becoming a full professor in 2000. In