After several hundred pages of describing biological anomalies that didn’t fit his theory of natural selection, on page 350 of his second volume of The Variation of Animals and Plants under Domestication, Darwin said the following, “Under this point of view I venture to advance the hypothesis of Pangenesis, which implies that every separate part of the whole organization reproduces itself. So that ovules, spermatozoa, and pollen-grains, – the fertilized egg or seed, as well as buds, – include and consist of a multitude of germs thrown off from each separate part or unit. In the First Part I will enumerate as briefly as I can the groups of facts which seem to demand connection; but certain subjects, not hitherto discussed, must be treated at disproportionate length. In the Second Part the hypothesis will be given; and after considering how far the necessary assumptions are in themselves improbable, we shall see whether it serves to bring under a single point of view the various facts.”
Darwin is wrestling with observations that don’t fit an established paradigm, the one that he and Wallace introduced in 1858 called natural selection. He is hypothesizing movement across a body and between generations of something that offers information that can be integrated into an ontological unfolding resulting in physical and behavioral change. “It is universally admitted that the cells or units of the body increase by self-division or proliferation, retaining the same nature, and that they ultimately become converted into the various tissues and substances of the body. But besides this means of increase I assume that the units throw off minute granules which are dispersed throughout the whole system; that these, when supplied with proper nutriment, multiply by self-division, and are ultimately developed into units like those from which they were originally derived. These granules may be called gemmules. They are collected from all parts of the system to constitute the sexual elements, and their development in the next generation forms a new being; but they are likewise capable of transmission in a dormant state to future generations and may then be developed. Their development depends on their union with other partially developed or nascent cells which precede them in the regular course of growth.” V2 pp. 369-370
What Darwin seemed to be feeling his way toward was endocrinology. Imagine endocrinology without genetics. Darwin hypothesized that gemmules display several features of gonadal hormones, however, hormones, when informing the next generation of useful information, don’t themselves store information in a dormant state.
Darwin was very focused on reversion. He felt that the ability of forebear features to emerge in future generations was an important clue to how ontogeny and evolution operate. “Reversion is not a rare event, depending on some unusual or favourable combination of circumstances, but occurs so regularly with crossed animals and plants, and so frequently with uncrossed breeds, that it is evidently an essential part of the principle of inheritance.” V2 p. 368.
Indeed, how specifically a body stores a record of ancestor solutions to their ancient environments seems integral to the mechanics of evolution. Darwin observed changes in environments compelling the reemergence of old solutions. He hypothesized that the same “granules” that share the information regarding environmental effects store the information for future use.
Evolutionary developmental biologists are exploring how genes behaving like “triggers” can take information from the environment and adjust development to enhance the ability of the individual to survive. Some of these switch systems are hundreds of millions of years old. Ancient switches suggest Darwin’s focus on how reversion operates, but Darwin is not talking millions of years but usually just up to hundreds of generations, perhaps sometimes thousands.
How does a genetic theory of evolution need to be framed or interpreted to make possible the genes that a person is offered being able to hold in memory a sequence of ancestor events, not unlike the phenotypic sequence vaguely evidenced by our ontological progression? In other words, ontogeny displays a general memory of ancestor phylogeny, or at least physical forms that suggest ancestor physical forms. I’m not committing to ontogeny recapitulating phylogeny, but perhaps our ontogeny reenacts ancestor ancient switching systems, somehow storing in some detail the sequence of responses to ancient environments. If this is the case, then perhaps the genes are not producing features but are producing a biological production, a play or symphony, that offers both a history of lives lived with environments responded to, along with an ability to respond to the present environment.
It seems to come back to music. Our genes are a musical score along with direction on how to build an orchestra. Each individual hires musicians to play the score, based upon what musicians are available (as informed by the environment). Each adjusts his or her playing to the other musicians hired. The music unfolds. Yet, somehow, that particular production, that life experience is recorded. The genes don’t change based upon that lifetime, but as with Darwin’s gemmules, information is carried forward to the next generation that shares a history of productions.
Is it possible that the history is stored in the environment? Might the score created by genes be but part of a larger score with vital information about the individual and the individual’s past stored in the scores around the individual?
This is different from Darwin’s gemmules. That which carries the information is different from how the information is stored. Nevertheless, as Darwin noted, “after considering how far the necessary assumptions are in themselves improbable, we shall see whether it serves to bring under a single point of view the various facts.”