Perhaps Darwin's most important insight was his realization that species are not immutable, that they can intergrade over time in an "insensible series." But what Darwin didn't have the courage to come right out and say, and what most evolutionary biologists in general don't have the courage to propose, is that there are really no such thing as species at all, at least not in the way we have traditionally defined them. Darwin should have realized this: he made it clear that natural selection happens at the level of individuals, never at the level of species. Evolutionary biologists have agreed with him, but have not taken the obvious next step: to declare that individuals living organisms are the only things that exist in the natural world, and that species (including animal species) may quite literally be figments of the human imagination.
If evolution occurs at an individual level then some imaginative theoretical pathways might explain the origin of genetic traits that confer unique properties to social insects like ants and bees.
Nutritional Control of Reproductive Status in Honeybees via DNA Methylation is a paper which appeared in Science. R. Kucharski, J. Maleszka, S. Foret and R. Maleszka are the authors. From genetically identical larvae either a queen or worker bees can develop. What possible evolutionary pathways led to this? Do you think evolution at an individual level adequately explains this and other unique social insect traits?