Vertebrates take very different routes to reproduction and caring for their young. Broods can be small or large, frequent or infrequent, and of large or small progeny. Some vertebrates lay eggs, some give birth to live young, some care for the eggs, some even care about their offspring – but many do not engage in any form of parental care, and neither warm nor feed their young. It is tempting to explain this immense variation in terms of the deep evolutionary divergence between vertebrate classes. I will try to show, however, that much of the variation occurs within rather than across lineages – and point to lower-bauplane constraints and geography as potential drivers of amniote life history traits.