A Side-Note on "Primitive" Life Forms

Here is a quick summary of how "primitive" bacteria replicate their DNA. It's quite obvious that this process didn't pop up "out of the blue". This is not a description of a "chemical reaction".

"Horizontal Gene Transfer" is also extremely important, especially in providing bacteria with a means to evolve by "borrowing" genes from other, unrelated organisms.

At this level of life on Earth, evolution is about gene transfer by any means possible. It is, in effect, a "wild west" scenario where genes struggle for survival with the survival of hosts (bacteria) being a side-effect. This is the scenario where Dawkins' "The Selfish Gene" seems most applicable.  At the time he wrote this book (as a young student himself), the seemingly mathematical rules of evolution were very much "in the air". The facts are more complicated. As you would expect, "Selfish Gene" was accidentally right about some things but was justifiably torn to pieces as a contribution to Darwinian theories of evolution. Even so, it established Dawkins as a TV-authority (talking head) and helped sell lots more books*.

Where "vertical" gene transfer dominates (parent to child - especially sexual reproduction), evolution operates on the organism (gene package). This is the domain of "Darwinian" evolution and biological theory.

When biologists analyze a sample - say from the forest floor or a deep ocean core - to see what bacteria are active, they look for what genes are present and active in the mush. It is seldom practical or even relevant to pin down particular "species" of bacteria.

For my purposes, the "wild west" scenario is useful in four ways:

• It illustrates a situation where the "individual" can be characterized by the genes it carries, creating overlapping categories of organisms that share the same gene. This situation will appear again at the "top" - super-organism level.
• It illustrates the need to think about these "levels" differently and not get stuck by thinking of "life" only in terms of our own "level", where organisms and sexual reproduction apply. In the big picture, life of our form is greatly outweighed by the other levels (such as bacteria). Pound for pound, they are more "successful" than we are.
• By recognizing the complexity of even the simplest life form, we are reminded of the huge leap from proto-life to the simplest form of life. The leap from "organism" to "super-organism" is another one, characterized by a complete re-design of the underlying "programming" and many orders of magnitude in the representative power of the "programming language".
• The "individual" organism is important in only one of the three levels of "life" I discuss here. It is important to set aside our idea that "life" is about the "welfare" of individuals, such as the "survival of the fittest" or "reproductive success". Those ideas apply only if the "program" is implemented in gene packages that are passed from parent to child.

It should be noted that we are not descended from bacteria - they simply represent an alternative and very successful architecture to extend (more or less) their form into the future. They are no more "primitive" than we are. In fact, they have fare more of generations per century and more options for variation than we do. In that sense, we could expect bacteria to be more sophisticated than we are, not less. But as Stephen J. Gould pointed out, evolution works in both directions, including simplification. There is no particular evolutionary trend or "pressure" that favors complexity. For this reason, a philosophical argument that depends on "evolution" from single-celled animals to human beings is flawed. What I call "fairy dust". Bacteria are just different, not more "primitive", nor do they provide much of a clue as to how life began in the first place.

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* "Selfish Gene" introduced the idea of a "meme" to illustrate Dawkins' idea that evolution might apply to other entities besides genes. The idea was taken up by himself and others more seriously than it deserved (mainly to support the concept of religion as an infectious disease). It was eventually disowned by Dawkins himself as a kind of "thought experiment". Even so, "meme" has entered the common vocabulary, applying to things like "viral videos". As it happens, the idea of the "gene" has proven to be less rigorous than what was thought when "Selfish Gene" appeared. When put to the hard test of predicting and explaining the world, both ideas turn out to be a bit fuzzy.

This entire blog may be taken to be a rebuttal of the idea that human culture is the result of "meme" evolution. Dawkins was grasping for another example of a "replicator". Dennett, takes the idea to ridiculous lengths, talking about Darwinian "evolution" of words. What is missing in all of this is the insight that humans have evolved (including significant areas of the cortex) to act as components of a culture. That's the foundation of what's going on. Language is a detail. And not all evolution is "Darwinian".

The ideas presented in this blog don't explicitly depend on either memes or genes, but I use these terms to point in the general direction of something being transmitted. Memes, in particular, are almost useless to shed light on deep structure in language.