Biological research on race has often been seen as motivated by or lending credence to underlying racist attitudes; in part for this reason, recently philosophers and biologists have gone through great pains to essentially deny the existence of biological human races. We argue that human races, in the biological sense of local populations adapted to particular environments, do in fact exist; such races are best understood through the common ecological concept of ecotypes. However, human ecotypic races do not in general (...) correspond with ‘folk’ racial categories, largely because many similar ecotypes have multiple independent origins. Consequently, while human natural races exist, they have little or nothing in common with ‘folk’ races. (shrink)

The project of this chapter is to understand what a phylogenetic tree represents and to discuss some of the implications that this has for the practice of systematics. At least the first part of this task, if not both parts, might appear trivial – or perhaps better suited for a single page in a textbook rather than a scholarly research paper. But this would be a mistake. While the task of interpreting phylogenetic trees is often treated in this trivial way, (...) in fact their interpretation is tied to foundational conceptual questions at the heart of systematics – questions whose answers are hotly disputed. As I will argue, common practices for the interpretation and use of trees are actually in conflict and therefore some must be given up. Here I defend the view that unacceptable principles about species as units of phylogeny must be given up. According to the view that I will develop, all phylogenetic trees depict the history of populations. The branches on trees represent collections of population lineages through time and the splits represent population lineage splits. I will argue for this view by focusing on how we use phylogenetic trees for inferences about the evolutionary past. (shrink)