On today’s ID the Future, philosopher of biology Paul Nelson discusses his chapter in a recent Harvest House anthology edited by host Casey Luskin, The Comprehensive Guide to Science and Faith. Nelson says the theory of universal common descent, a key component of modern evolutionary theory, has generated multiple predictions that have failed. The prediction he discusses here is that there would turn out to be a single universal genetic code, since that’s what we should expect if all life on earth is descended from the last universal common ancestor (LUCA). Findings over the past three decades have proven that prediction spectacularly wrong. How does the theory of universal common descent shrug off this contrary empirical finding? The trick for LUCA in this and similar cases is to shift blame for failure to an ancillary theory. It’s a clever move, says Nelson, but it comes at a cost.