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Edit: just to clarify, I am asking what, if anything, the literature says can be gleaned about evolution by studying cancer, especially relating to how multicellularity evolved and the traits used to force cells under control of the organism.

Most of the original question details I had added were just my own thoughts on the topic.

Original question

Is there a sense in which cancer can be considered as a return to the unicellular "origin" of a cell?

It has always seemed to me like cancer is almost inevitable by the structure of the cell (its poor "design", essentially). The only thing standing in the way are the cellular controls: senescence/apoptosis (e.g. p53 pathway), immunosuppression (e.g. cytotoxic T lymphocytes), telomeres, etc...

So it seems like multi-cellularity did not evolve "ground-up", but was instead generated by slowly differentiating the functions of the various cells, while developing "top-down"controls against errant cellular behaviour. Thus, cancer, which occurs when these protections fail, is in some sense merely a return to an ancient evolutionary root.

I suppose some arguments against this include the fact that modern cells are vastly different than their ancient ancestors (or even modern archaea/bacteria). So the best we can perhaps say is that the core of the cell has been sufficiently preserved (ribosomes are still mostly RNA, are they not? :] ). Further, it is hard to call some of the "micro-evolutions" of cancer (e.g. interleukin-8 production) as returns to primitive behaviour. In these cases, I tend to see them as necessary occurrences to remove the "top-down" controls, rather than as integral to the destructive out-of-control growth characterizing oncogenesis. But, debatably, perhaps not all of them are (e.g. extravasation in metastasis).

Obviously this seems very simplistic, but is there any literature thinking about it this way? Or directly debunking it?


marked as duplicate by David, canadianer, Bryan Krause, WYSIWYG Sep 25 '17 at 8:29

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  • $\begingroup$ Aside from anything else, your assumptions about multicellularity evolution seem off. For example see The evolutionary-developmental origins of multicellularity (press-release version: From one cell to many: How did multicellularity evolve?) $\endgroup$ – iayork Sep 20 '17 at 16:47
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    $\begingroup$ While commending you for wishing to think about and discuss science, it has to be pointed out that this is question and answer site, not a discussion site. It is worthwhile reading the Help on What type of questions should I avoid asking to see why close votes are accumulating on your question. I would say it comes under the categoriy there of "there is no actual problem to be solved: “I’m curious if other people feel like I do.”" i.e. you are inviting discussion of an idea. Some other forum (Cynics?) may accommodate you. $\endgroup$ – David Sep 20 '17 at 21:37
  • $\begingroup$ @David I'm aware that this isn't a discussion site, which is why I asked specifically for literature. Thanks for your comment anyway though. I understand that the question is not exactly the cut-and-dry basic questions that this site seems to prefer. It may well be closed anyway, though I am not sure why it is so much worse than many of the other questions here.... $\endgroup$ – user3658307 Sep 21 '17 at 1:33
  • $\begingroup$ Well, you seem to have changed your question and title now, and although I still think it's off-topic I'll leave things there. However I can't ignore the last sentence of your comment. Let me rephrase it: "Why pick on me officer? I wasn't the only one exceeding the speed limit. And some were going even faster." $\endgroup$ – David Sep 21 '17 at 8:16

Cancer and level of selection

Cancer results from the opposite action of different level of selection. There is selection on the population of multicellular individuals and there is selection on the population of cells within each multicellular individuals.

There is selection among cells within an individual for increase replication rate while there is selection among multicellular individuals in the population for controlled replication rate of their cells.

Major transitions

The passage from small unit of selection to bigger units is called a "major transition". Such transitions include the grouping of genes on chromosomes, the grouping of cells onto multicellular individuals, the grouping of multicellular individual onto colonies and, if there are several planets inhabiting life in the universe, then the grouping of life forms in every planet into a population of living planets. One can list other, more extreme or intermediate major transitions but there is quite a bit of debate on what really constitute a major transition.

Literature on the subject

[I]s there any literature thinking about it this way?

The keywords that will help search further information are group selection, kin selection, major transitions.

I recommend having a look at Major Transitions In Evolution by Maynard Smith and Szathmary and also The Major Transitions in Evolution Revisited by Calcott and Sterelny which is a book made of many small parts, each written by a different author on these same questions of level of selection.

You might eventually have a look at Evolutionary Dynamics: Exploring the Equations of Life by Nowak as well.

These discussions of level of selection include discussion of what an individual is and what level is most important. The extremely popular and well written books by Dawkins will also bring you some light on the subject. Consider The extended phenotype for example.

For more book recommendations in evolutionary genetics, please have a look at Books on population or evolutionary genetics?.

If you like the sensation of thinking of the entire earth as an individual part of eventually a larger group of living planet, then you'll maybe enjoy having a physiological / ecological view of this living planet earth with Gaia by Lovelock


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