A Species within a Species
Chapter 1 introduces cancer as a speciation event that is inexorably linked to multicellularity and marked by a return to unicellularity. Although each cancer arises as an independent speciation event, common ecological features drive convergent evolution of most cancers, resulting in the cancer hallmarks (key phenotypes critical for cancer cell survival and reproduction). These ecological landscapes also change over time and circumstances; this chapter argues that these changing ecological landscapes are crucial to whether malignant tumors will evolve and how tumors will respond to treatment. Moreover, cancer cells are not just shaped by the environment but also through various mechanisms. Much like beavers arriving at a stream for the first time, the cancer cell population reconstructs the landscape, leading to a more permissive environment for the cancer cell population. This niche construction is important in understanding cancer progression and has ramifications for treatment. These topics of the interactions of cancer cells with their environments, changing ecological landscapes, and niche construction are explored in subsequent chapters.
