Uganda’s Anti-Gay Law: The Missing Science by Helen Epstein | NYRblog | The New York Review of Books

"Sexual preference may be analogous to the immune system. In the 1950s and 60s, Peter Medawar, Gerald Edelman, and others discovered that everyone’s immune system is unique. The complex collection of genes that determine how each one of us will respond to a particular germ are incredibly diverse and no two of us have exactly the same set of such genes—not even identical twins. That’s because the building blocks of our immune systems are created partly upon conception when sperm and egg meet, partly during embryonic development, and partly after birth in response to real-world germs."