The journal Theoretical Medicine and Bioethics just released online my review of Maureen L. Condic’s book Untangling twinning: what science tells us about the nature of human embryos, published in 2020 by the University of Notre Dame Press.  Here’s how the review begins: When does an individual living human organism come into being? If one argues “at conception,” then one must deal with the perplexing problem of monozygotic twinning, which occurs after conception and before the beginning of the primitive streak. At some point during... Read more