Distributed and Shared Genetic Value

Distributed and Shared Genetic Value

Print Friendly, PDF & Email

Richard Dawkins, as I noted in my previous essay, wants to interpret all genetics under the model of selfish genes. Again: “We are survival machines–robot vehicles blindly programmed to preserve the selfish molecules known as genes” (1989, p. v). This is the only “orthodoxy” (1989, p. viii, 1976) now permitted in biology. We made last time the point that those versed in the philosophy of science need to ask whether Dawkins is framing up genetic activity pejoratively, projecting onto genes an activity drawn from the human moral realm. Last time, I invited considering an alternative frameworks that could accommodate the same activity equally well as a self-actualizing organism defending its intrinsic values, values that had also to be propagated in species lines.

Consider now still a further alternative framework, that of genetic “sharing.” I use the word “share” both as a descriptive term and as a deliberate corrective to this “orthodox” word “selfish.” “The selfish gene” is vivid imagery. But imagery needs philosophical analysis, especially imagery that colors worldviews, even more if this seems to have scientific sanction. When scientists speak of ant wars, or queen bees and their slaves, or immunoglobulins as carrying on a “battle within” us against invading microbes, they borrow words from one domain of experience and transfer them to another. A careful analyst needs to be cautious about overtones also transferred. A great deal depends on the metaphors one chooses, since these so dramatically color the way we see the natural world. One must be careful not to let negative moral words, borrowed from culture, discolor nature. Something like this happened before in Darwinism when “survival of the fittest” was the paradigm, interpreted as “nature red in tooth and claw,” but biologists now prefer to restate this as “adapted fit,” a better description, since fitness takes place in various ways, only one of which is combative or aggressive. “Adapted fit” colors events differently from “survival of the fittest.”

Recall that theoretical biologists have come to incorporate this organismic genetic “selfishness” into that they call “inclusive fitness” (Hamilton, 1964), because nothing is more obvious in biology than that animals often defend their own kin. So at least kin have to be included in this “selfishness,” genes have to be “shared” with kin–“selfishly shared” an orthodox Darwinian (perhaps better called an orthodox ultra-Darwinian will have to say.

But does not this opening up to be more inclusive invite asking how far genetic information is shared. The more neutral word here is “distributed”; but now that the individual self has become implicated into an “inclusive” fitness we can introduce, rather provocatively, the word “shared” with which to interpret this genetic “allocating” and “proliferating.” “Share” has the Old English and Germanic root, “sker,” to cut into parts, surviving in “shears,” “plowshare,” and “shares” of stock. As used here, to “share” is to distribute in parts the self’s genetic information, thereby conserving it. Genes do generate; they reproduce or communicate what survival value they possess; they share [=distribute in portions] their information, literally, although preconsciously and premorally. The central feature of genes is that they can be copied and expressed, again and again. They replicate. Their power to send information through to next generation is what counts. The genetic information gets allocated and reallocated, portioned out, and located in various places. Whatever the process, rather obviously genetic information has been widely distributed, communicated, networked, recycled, and shared throughout natural history.

Take two examples, the first at basic metabolic levels. Some genes code for making cytochrome-c molecules, and these are found in organisms ranging from yeast to persons, that is, they are extremely widely shared. They are vital in the energy metabolism of all higher plants and animals and go back some 1.5 billion years, to the early history of life. Cytochrome c molecules do evolve through various nucleotide substitutions, but are comparatively stable molecules. The primary structure is identical in humans and chimpanzees, which diverged about 10 million years ago; there is only one replacement between humans and monkeys, whose most recent common ancestor lived 40 to 50 million years ago. Even between humans and yeast the code is more than half the same, and, where it is different, the differences are often inconsequential in function (Dickerson, 1971; Fitch and Margoliash, 1967).

Similar observations could be made regarding genes that make adenosine triphosphate (ATP), biotin, riboflavin, hematin, thiamine, pyridoxine, vitamins K and B12, or those involved in fatty acid oxidation, glycolysis, and the citric acid cycle, or those that make actin and myosin. These metabolic skills are quite extensively shared by living organisms–or, if you like, quite “inclusively” distributed because their know-how has been transmitted over the millennia on the genes.

As a second example, restricted to primates, consider what Homo sapiens holds in common with chimpanzees. Mary-Claire King and Allan Wilson find that the difference in the protein coding sequences of DNA for structural genes in chimpanzees and humans is quite small. “The average human protein is more than 99 percent identical in amino acid sequence to its chimpanzee homolog” (King and Wilson, 1975). Differences between the two species lie largely in regulatory genes.

E. O. Wilson recognizes this: “We are literally kin to other organisms. … About 99 percent of our genes are identical to the corresponding set in chimpanzees, so that the remaining 1 percent accounts for all the differences between us. … Furthermore, the greater distances by which we stand apart from the gorilla, the orangutan, and the remaining species of living apes and monkeys (and beyond them other kinds of animals) are only a matter of degree, measured in small steps as a gradually enlarging magnitude of base-pair differences in DNA” (1984, p. 130).

[Caution here: The similarity can be overemphasized. These estimates are for structural genes. The regulatory genes are not included here, which govern behavior, among other things. Many regulatory genes will also be similar between chimpanzees and humans, but many will not. Further, there is much more room for differences than the 99% identity in amino acid sequences recognizes. Only about three percent of the human genome codes for proteins; 97% does not, and this other DNA varies so widely between species, even between organisms of the same species, even between cells of the same organism that it is difficult to interpret. This has been misinterpreted as “junk DNA,” but geneticists increasingly see it as vital to life (Nowak, 1994).]

In any case, the vital structural information for making the advanced primate body has been widely shared for millions of years. Similar points could likewise be made with the basic vertebrate body plan, or hearts, livers, kidneys, and so on.

The genesis of biodiversity and complexity, so striking in natural history, is possible only as information found out by these searching genes is widely distributed, carried on from one generation to the next in such way that it cumulates, is tested in experience, discarded where it is found to be less fit, selected and conserved where it is found to be more fit. That has happened with cytochrome-c molecules and with primate protein structures.

Genes must find a method of distributing and elaborating, of proliferating what values they contain and conserve. That process makes possible the genesis of life, the accumulation of all those values inherent in biodiversity and complexity. Along with the word “distribute,” en route to the word “share,” consider another, relatively neutral word: Genes “divide.” They “divide” in order to “multiply.” Life must be enclosed in cells; yet cell division is required for cell multiplication, for ongoing life. The cell division requires genetic division. “Dividers” are required to partition out their goods and this multiplies such goods. Such division and distributing, replicating, recycling, together with adapted fitness, places each gene where it belongs, in a commons in which it participates. The gene is engaged in dispersing vital information, in transmitting its intrinsic values. Communicated information, transmitted when a gene reproduces, has in fact been “re-produced,” produced again. Genes, in their most fundamental character, are bits of valuable information, coding bytes, in a world where vital information, the secret of life, has to be dispersed if life is to continue. Genes are a flow phenomenon.

There is nothing pejorative about either biological conservation, or, what is the same thing, biological division. The dividing, reproducing organism is not so much an irremediably selfish self, defending the whole organism that it alone constitutes, and defending slivers of a self in others; rather here are values, instantiated in the self, and conserved by distributing them, by defending them wherever they are present as a result of the various cellular and genetic divisions, and thereby replicating and multiplying them. This results in the transgenerational contributing of genetic values, the only kind of values that the organism has.

When used in ethics, “share” has a positive moral tone, and our point in using it biologically here, additionally to describing what is going on, is to neutralize, to un-bias, the negative moral tones left by “selfish.” “Share” is difficult to interpret selfishly. When genetic information is passed on to a next generation, when that information overleaps death it would seem as appropriate to say that it has been “shared” (distributed) as that it has been “selfishly” kept.

Genes are no more capable of “sharing” than of being “selfish”–it must at once be said–where “sharing” and “selfish” have their deliberated, moral meanings. Since genes are not moral agents, they cannot be selfish, and, equally, they cannot be altruistic. But genes can transmit information; and, if one is going to stretch a word sometimes employed in the moral world and make it serve in this amoral, though axiological realm, then “share” is as descriptive an interpretive framework as “selfish” and without the pejorative overtones. Sometimes one has to lean into the wind to stand up straight. “Dividers” and “multipliers” too find it hard to be selfish. The survival of the fittest turns out to be the survival of the sharers.

We do need to choose our words carefully–“distribute,” “disperse,” “allocate,” “proliferate,” “divide,” “multiply,” “transmit,” “recycle,” or “share” in “portions.” We want a nonhumanistic, nonanthropocentric account, one unbiased by our morals, either for worse or better. The distributive account is a much more descriptive paradigm, because there is no good reason to think that genes are selfish; there are no moral agents in wild nature even at the organismic level, much less the genetic one. But there is good reason to think that there are objective, nonanthropocentric values in nature, on which survival and flourishing depend, and that these are defended and distributed by wild creatures in their pursuit of life. Only humans are moral agents, but myriads of living things defend and reproduce their lives.

I am using value vocabulary–genetically valuable information is widely shared–but the point here is that in the genetic world such “value-based” vocabulary is more accurate descriptively than is “morally-derived” vocabulary, for genes essentially are information, and information is of value. A gene is an information fragment, a puzzle piece in a picture of how to make a way through the world, and such a fragmentary piece can be of value to survival. That is not a selfish thing; that is a valuable thing. We are first describing what “is” the case when we model the phenomena so; and, after that, we may also value such value, often prescribing that such value not only “is” present, but “ought” to be conserved in the world. What kindred organisms have is a set of shared values, more or less.

From this point of view one can worry that the “selfish gene” perspective is driving a humanly-biased value-laden interpretation of nature, one which has become a kind of paradigm. The jaundiced view is not coming from nature, but from the lens through which the sociobiologist or behavioral ecologist promoting such views is looking. Looked at though the lens of biologically-based values, the system contains intrinsic values (such as the somatic lives of individuals, defended for what they are in themselves, transmitted to others); it also contains instrumental values (such as one organism depending on another, or parenting that contributes to the welfare of offspring, or food chains with organisms eating and being eaten). Every such value is networked interactively into ecological systems, of systemic value. Increasing complexity and diversity require both logically and empirically increasing specialization of parts and roles, which requires increasing coaction, cooperation, and interdependence of these evolving selves. The evolutionary and ecosystemic arrangements require for these values initially to be generated and then re-generated, and subsequently distributed and shared over many millennia. The means to this end is genes.

References:

Dawkins, Richard, 1976. The Selfish Gene. New York: Oxford University Press.

Dawkins, Richard, 1989. The Selfish Gene, new edition. New York: Oxford University Press.

Dickerson, R. E., 1971. “The Structure of Cytochrome c and the Rates of Molecular Evolution,” Journal of Molecular Evolution 1:26- 45.

Fitch, Walter M., and Emanuel Margoliash, 1967. “Construction of Phylogenetic Trees,” Science 155:279-284.

Hamilton, William D., 1964. “The Genetical Evolution of Social Behavior. I and II,” Journal of Theoretical Biology 7:1-52.

King, Mary-Claire and A. C. Wilson, 1975. “Evolution at Two Levels in Humans and Chimpanzees,” Science 188:107-116.

Nowak, Rachel, 1994. “Mining Treasures from `Junk DNA,'” Science 263:608-610.

Wilson, Edward O., 1984. Biophilia. Cambridge, MA: Harvard University Press.