I just skimmed this article, but it doesn't appear to make the interesting point that came to my mind when reading it, which is: in a multicellular organism, what the article calls a "cheater", we call a "cancer". A "cheater" is just a cell which, despite its common origin, has mutated to compete with the other cells instead of cooperate with them. And indeed, we see cells do that; we also see adaptations -- the tumor suppressor genes -- specifically designed to inhibit such cells.
Isn't this kind of a confused presentation? (I'm talking about the popular article, of course; I have no doubt the researchers know their stuff.) The cells of multi-cellular organisms like whales and humans aren't just cooperative, they are genetically identical, which means their evolutionary prospects are tied together. The DNA in a pancreas cell is the same DNA as in a sperm cell, so it's "in the pancreas cell's interest" to help out the body. (Really, the key idea is the evolution is a competition between the bits stored in DNA, not the physical DNA itself.) And the root reason the cells of multi-cellular organisms like whales and humans are identical is because of sexual reproduction. So the key bottleneck isn't the one-ness of the one cell, it's the genetic identical-ness.
Now, yes, once you say all that I guess you can say that the mutations in animal cells leading to non-cooperative behavior (i.e. cancer) are evidence of this 100-division limit. But the amoebae are qualitatively very different since they aren't all genetically identical. It's really closer to the cooperation between human * families* than human cells, isn't it?
They found out that the pathogenic mutation was only present in vascular tissue, but not in blood cells.
DNA replication errors occur all the time, even in multi-cellular organisms. Some of them lead to cancer, but most of them are either lethal (for the cell), or, most of the time, innocuous.
The most likely scenario for the abdominal aortic aneurism is the following: A mutation can occur during organogenesis, in utero. The earlier it occurs, the more cells will be affected. Said mutation can be initially benign, but become problematic in the long run. If the mutation occurs after the differentiation between fibroblasts and blood progenitor cells, only affecting the former, you get the scenario described in the ScienceDaily article.
> The cells of multi-cellular organisms [...] are genetically identical
Nope. As stated in another comment, somatic mutations occur all the time, leading to slight diffenrences between the cells of a given multi-cellular organism. Most of them are insignificant, though.
