The cellular mechanism of evolution is offered as a way of understanding the Joint Points in the ToK 'map'. It is founded on the First Principles of Physiology- negative entropy, chemiosmosis and homeostasis. The First Principles of Physiology are a prediction of the cellular approach to evolution. They were determined by 'reverse-engineering' the process of physiologic evolution by superimposing the cell-cell signaling mechanisms for embryologic development on the phylogeny of vertebrates. For example, the evolution of the lung refers all the way back to the introduction of cholesterol in the cell membrane of prototypical cells. When that is seen in the forward direction as evolution, the cholesterol acts to maintain the physiology of the lung alveolus. So there is a continuum from the unicell to the complex physiology of the lung, and all of the in between steps. The cell-cell signaling mechanisms involved offer connections to other physiologic properties like that of the glomerulus of the kidney, the skin, the skeleton and brain. In the aggregate, all of these cell-cell signaling mechanisms are what is conventionally thought of as the brain/mind. That is particularly true of the skin, since it is the phylogenetic/evolutionary link between the nervous system of the skin and brain.
References
Torday JS, Rehan VK. Evolutionary Biology, Cell-Cell Communication and Complex Disease. Wiley, 2012.
Torday JS, Rehan VK. Evolution, the Logic of Biology. Wiley, 2017.
Torday JS. The Singularity of Nature. Progress in Biophysics and Molecular Biology. 2018