Toward a Biology Worthy of Life > Genes and the Central Fallacy of Evolutionary Theory > Brief excerpt
A project by Stephen L. Talbott

Contexts and activities, not things, are inherited (2)

Consider the rapidly growing interest in transgenerational epigenetic inheritance (Lim and Brunet 2013). This inheritance is commonly thought to be mediated by methyl groups attached to DNA nucleotide bases, by chemical modifications of the protein histones around which much of our DNA is wrapped, and by various small RNA molecules. But concerning all these factors the literature today is shrill with warnings that their effects are context-specific. So it is the context, and no particular thing as such, that “carries” the heritable effect.

Why, then, should we restrict our attention to these particular factors — or to other material elements that likewise can be more or less repeatably and reliably tracked? Such factors may indeed serve as suggestive markers for us, but what is fundamental for both the functioning of the organism and for inheritance is the context as such. And the functioning of this context — by the very nature of contextuality — cannot be rigidly equated with particular local configurations of elements that may happen to reappear in successive contexts.

In slightly different words: what we need is not so much the stable transmission of thing-like replicators as the stable intention of the organism itself. Here “stable intention” is not too mysterious for biologists to face. It refers to something like the directedness and adaptive stability we already witness in individual development. And this individual development is not separable from the processes at work in evolution. After all, the individual’s physical body is potentially “immortal”, inasmuch as it passes alternately through an expansionary phase of development and then a contraction into the still living germ cell, followed by another expansion. There is never anything but continuous life in this ongoing narrative. The living, directed capacities we see in the passage from adult to germ cell and zygote are not different from the capacities we see in the passage from zygote to mature adult.

The one-celled zygote, as a whole organism, is the bearer of this narrative, and therefore is the heritable substance. It does not develop into an organism under the autocratic control of just one of the contents it effectively coordinates; it already is the whole organism. This is why it can so deftly execute the subsequent spatial re-organizations, cell divisions, normal developmental processes, and adaptations to unforeseeable disturbances, all in order to produce the orderly stages of its own existence. The passage of this directive capacity down through the generations is the essence of inheritance, and any evolutionary process must derive in the first instance from changes in the overall character of the activity.

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