Last year, I visited Whittington in Sydney to talk about her work on platypus venom. She told me then that she was also studying the evolution of live birth. She was curious whether all of these animals that independently evolved live birth are using similar genetic pathways to get there. “Is there some set of genes that are particularly good for providing the functions of pregnancy?” she wondered.
Whittington and other scientists will need a lot more genetic data from species that become pregnant to determine just how similar we are. And only then will the researchers be able to tell the story of how this complex form of reproduction came about so many times in so many different critters.