Amoebae fusion

My hypothesis otherwise remains what it was in 1993 - the epithelial component originated from an epithelial animal and the amoeboid component originated from an amoeboid animal equipped with a protocnidocysts, and possibly already living as an intracellular parasite on the epithelial animal during some stage of its life cycle. One or another device for cell fusion would have to be invoked to explain how an amoeba and an epithelium... 

In higher organisms, cells with specialized functions are derived from stem cells in a process called differentiation. Stem cells have many of the features of a primitive unicellular amoeba, so in some senses differentiation is like evolution, hut it is played out on a much shorter time scale. This takes place most dramatically in the development of a fetus, from the single cell formed hy the fusion of one spermatozoon and one oviun to a vast array of different tissues, all in a matter of weeks. 

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