This chapter explores the debates over human origins in the popular media to show how the topic influenced the ways in which Darwin’s theory was perceived (and misunderstood). The impact of the public’s fascination with the gorilla as a possible human ancestor helped to sustain the image of evolution as the ascent of a ladder. The cultural evolutionism promoted by archaeologists and anthropologists also adopted the linear model of development. Physical anthropologists saw the allegedly ‘lower’ races as intermediate steps in the ascent from the apes, in effect as ‘living fossils’ filling the gap created by the lack of genuinely ancient remains at the time. The impact of Darwin’s Descent of Man is explored in the context of the existing preconceptions generated in the 1860s. The relationship between general models of evolution and emerging ideas of social evolution, not all Darwinian in form, is explained.

Evolutionary ideas were in circulation before Charles Darwin began his work and were widely disseminated, arousing much controversy. In addition to the writings of Erasmus Darwin (Charles’ grandfather), French ideas gained some currency in the English-speaking world, especially the views of J. B. Lamarck. These ideas were taken up by radical thinkers who rejected divine creation, to the horror of conservatives. Early discoveries of fossils played a significant role in arousing public interest in the history of life and were often seen as evidence that life had ascended a scale of development (the chain of being) toward humanity. The first-known dinosaurs were fitted into the chain as gigantic lizards, not as evidence of creatures totally unlike anything now alive. This model was adapted to middle-class values in Robert Chambers’ Vestiges of the Natural History of Creation in 1844, again arousing controversy but gradually gaining some credibility beyond the scientific community.

In this chapter I address flaws in lineage thinking that are common in the professional, popular, and eductional literature, and which result from confusing the branching relationships between collateral relatives in the realm of systematics with the linear relationships between ancestors and descendants in the realm of evolutionary descent. The influential voices of the late Stephen Jay Gould and Robert O’Hara, who dubbed the now ubiquitous phrase ‘tree thinking’, have warned readers for decades against the sins of linear evolutionary storytelling and the use of linear evolutionary imagery. However, I argue that their impact has been deeply pernicious. The writings of Gould and O’Hara fundamentally misconstrue the relationship between the branching realm of systematics and the linear realm of evolving lineages. I close with a discussion of the problem that, in the absence of a vocabulary designed to talk about lineages, we are forced to discuss them in the taxic language of systematics. This inevitably causes problems.