You have put your finger on one of the mysteries I’ll be grappling with in the book. In developed countries with reasonably competent record-keeping, changes in the incidence of different kinds of cancers can be plotted. And even then the causation is controversial — how much is from early detection and how much from diet, exposure to carcinogens, etc.? When you look back even a century, death records become much less reliable — and cancer was considered a stigma so another cause of death was often listed. Go back even further and you are relying on scant historical records and the archaeological ambiguities I wrote about in the article.

Also, what about animal skeletons? Must be many more of them unearthed, right? If Weinburg’s idea about multicellular life holds true, then shouldn’t we also be able to track it in animal remains? Or do most animals die from predation before cancer would have had time to kick in?

Clearly, you’ve got me interested…