Mosaicism: The genome varies from cell to cell

Re:Mosaicism: The genome varies from cell to cell by lisper on Tuesday May 22, 2018 @06:39PM (#17130011)

To really answer this you should read "The Selfish Gene." But the TL;DR is that the unit of selection in Darwinian evolution is neither the organism nor the group, but the gene. Ant colonies are the phenotype of a group of genes that glommed together over the years to form an evolutionarily viable unit. But the unit is not what is being selected ever, it's the individual genes. The phenotype of a gene is not necessarily constrained by any physical boundaries. (For example, the phenotype of the human genome extends into outer space!)

[ Parent | on HN ]

Re:Mosaicism: The genome varies from cell to cell by haberman on Tuesday May 22, 2018 @07:33PM (#17130355)

> To really answer this you should read "The Selfish Gene."

I did. Well the first several chapters at least. I did not find a convincing answer to the question I am raising here.

> The phenotype of a gene is not necessarily constrained by any physical boundaries.

Sure it's not necessarily constrained. But in practice there is very high correlation between family relatedness and physical proximity / social group.

If the main rebuttal against group selection is "families can be spread out", I don't think that warrants the level of criticism that is leveled at it. An organism surrounded by genetically unrelated peers is the exception, not the rule.

EDIT: Reading a bit more, I think I may be understanding this distinction better. "Kin selection" and "group selection" are more different than the names suggest. "Kin selection" means that natural selection incentivizes an individual to be altrustic towards their own kin. "Group selection" means that natural selection will favor the survival of an entire group over another group based on the comparative genetic strengths of the two groups.

[ Parent | on HN ]

Re:Mosaicism: The genome varies from cell to cell by lisper on Tuesday May 22, 2018 @08:10PM (#17130529)

Yes, your edit got it exactly right.

[ Parent | on HN ]