
How birds become male or female, and occasionally both - Guest Work
Guest Author • Mar 13, 2019 •
Jenny Graves, La Trobe University The highly unusual “semi-identical” Australian twins reported last week are the result of a rare event. It’s thought the brother and sister (who have identical genes from their mother but not their father) developed from an egg fertilised by two different sperm at the same moment. In humans, it’s the sperm that … Read More