Thesis #13 – The declining forces of natural selection lead to an evolutionary failure to establish the genomic information required for tuning the complex networks of life well enough to provide a high level of health indefinitely; there is no mechanistic necessity at the level of physiology to this failure.
It is intuitively hard for people who have never seen diagrams of solar systems to absorb the concept of a heliocentric solar system, in which the Moon orbits Earth, but Earth orbits the sun. But with such diagrams and a patient science teacher, most people get over the naturally-geocentric intuitive view.
It is still harder to get people to absorb the present-day Darwinian explanation of aging, as derived from Hamilton’s Forces of Natural Selection. I have been failing at this task for decades, and I am not alone. The problem is that the meaning of the equations and scientific diagrams that we use to explain the theory is not as intuitively accessible as diagrams of solar systems.
But I recently thought of another way to convey the idea. The key is to understand that animals and the cells that they are made from are extremely complex machines that function because of information stored in their genomes. That information is built by natural selection. When natural selection is impaired, by mutation or inbreeding for example, the information underlying function is degraded. That is, functional information from the genome is built by natural selection, to the extent to which natural selection can, given the evolutionary situation.
Some of this information is age-specific. So there is genetically encoded information that effectively “instructs” the mammalian fetus how to develop prior to birth. There is also genetically encoded information that effectively instructs the developing mammal to undergo a process of sexual maturation, in order to reproduce. All this information was produced in our evolutionary past thanks to the full force of natural selection acting at ages before the start of reproduction.
But natural selection has been under little pressure to specify instructions for useful function at later adult ages. It is not that there are material difficulties with sustaining life which natural selection cannot overcome; as we will discuss later in the 55, natural selection can easily do so. It is just that natural selection hasn’t bothered to develop the information for our indefinite survival. The information isn’t there. There is nothing to “read off” of the genome with which to sustain our youthful health. Those pages of our genomic instruction manual are either blank or defaced.
Unlike God in Woody Allen’s movie “Love and Death,” natural selection is not an underachiever when it comes to our aging. It just doesn’t care. Or you can think of it as a novelist or screenwriter who loses interest as they proceed through the drafting of their work. The last chapters just haven’t been written.
Physiologically, to the extent to which the genome doesn’t have useful instructions for later survival or fertility, it is going to become harder for the animals with that genome to survive or reproduce.