Nobel Prize winner V. Ramakrishnan (Biology and Medicine, 2009? for the study of ribosomes) is a first-class mind. He refutes most of the myths about mortality. When there is a theory of mortality, he explains that the things are more complicated than meets the eye. All in all, we don't know why we die. There are many mechanisms of aging and apoptosis on the cellular and sub-cellular level but none can consistently explain longevity of organisms across the species.
Some of the reasoning of Ramakrishnan is deficient. For instance, similarly to Dawkins, he argues that group selection is impossible because in the case of mutation beneficial for the group but imposing cost on the individual, the individuals without this mutation would outcompete the mutated individual in their progeny.
This is not convincing because, for instance, there could be several mutually incompatible mutations both leading to evolutionary success. In an imaginary example, a bird of prey can be more successful hunter by flying quieter or flying faster. These properties may be incompatible by fluid mechanics or genetics. Individual having both mutations faces a double energy cost. So it is likely that the population would include both species. Economists call this a separating equilibrium.
Owls are not eusocial, so the story ends here. But, for a tribe, a population of excessively aggressive individuals due to random mutation, who consume resources much in excess of minimal needs (soldiers), and individuals who produce food in excess of their individual needs (peasants), obviously is beneficial in terms of survival of both. The tribe becomes well defended and well fed, which is impossible by preponderance of a single group in genetic makeup.
There is another train of thought concerning decreasing returns of workers with aging and the need for retirement. However, this reflects the look from the ivory tower of Cambridge, also similar to Dawkins'. The problem is that the countries steadily increase the pension age. But the jobs available for those without Cambridge private pensions are exceedingly rare. And most of them are poorly suitable for the age. I provide a short list.
School bus driver.
Security guard.
Medical orderly.
Airline baggage handler.
And so on.
