A quick search revealed at least one thread asking a question about what is alive, but I am specifically interested in genes.
I have been rereading The Selfish Gene and while Mr. Dawkins seems to carefully layout his definitions and to be very precise in his usage of most terms, he casually says that genes live in our cells. Given the premise of the book, I am not surprised. It does confuse me a bit that — in the edition I’m reading — he writes several paragraphs in defense of his use of a computer as an analogy for the brain, yet he doesn’t mention a word about the idea that genes should be considered alive.
Maybe this would be better suited to IMHO, but I personally feel that there must be some factual answer to this question.
I don’t think that anyone can factually answer this question.
A word of advice about Dawkins. I am currently reading my first Dawkins book. He makes a lot of educated guesses about how things work. If you read carefully, he admits as much himself. Don’t missunderstand this as disrespect, his guesses are very well educated. He certainly knows more than I do about a great many things, and I can find no fault with his logic. Just don’t take his word as gospel. I’m sure he would tell you the same.
As for The Selfish Gene, it’s been some time since I read it but I do remember he used quite a lot of anthropomorphism to explain the behavior of genes. At the same time, he also cautioned many times that he was doing it to add explanatory power and that no one should be fooled into thinking that genes have motives or plan ahead – he was simply using a tactic that other scientists might use, such as a physicist asking what a photon “wants to do” in a given situation or a chemist asking what an ionized particle “wants to do” when paired up with other particles, etc.
I am reading Climbing Mount Improbable. It is turning out pretty much as I expected, but it’s nice to see the principles of natural selection demonstrated.
Unfortunately, although common, this use of allegory has led many people without adequate reading comprehension skills (most notably philsopher and professional idiot Mary Midgley, but also (mostly) reputable scientists Lynn Margulis) to misinterpret his claims as being teleological or deterministic, which of course it dramatically at odds with the theory he presents. Well, you can’t cure idiocy.
Climbing Mount Improbable is one of Dawkins better books, along with The Blind Watchmaker, The Selfish Gene, and with caveats, The Extended Phenotype. You do have to account for the fact that Dawkins is the foremost proponent of gene centric theory, which is to a certain extent widely but not universally accepted, and even within propoents there is much debate over the role that genes play vis a vis phenotypes. Dawkins has a very definite view on this which is not necessarily representitive of evolutionary scientists as a whole though with more accurate mathematical models it is clear that the genome plays a substantial role in resultant development and behavior.
As a counterbalance to Dawkins, I suggest taking in a couple of Ernst Mayr’s sage volumes, particularly This Is Biology: The Science of the Living World and What Evolution Is. Mayr, a recognized leading figure in evolutionary biology, is very much an opposite of Dawkins in terms of his approach to evolutionary mechanisms and is very adamently not a gene centrist. You’ll get a more comprehenisve picture by reading both, and Mayr’s a good writer, though What Evolution Is does tend to get a bit dry.
Dawkins is not, as he has been painted by critics, a genetic determinist, though, and in his social philosphy he describes himself as a humanistic socialist, believing that conscious behavior can trump genetically-derived instincts. The most off-putting thing about Dawkins is his proselytizing against religion; even though I agree with him in large measure, he frequently injects it where it need not belong and with a vitrol that is misplaced. One of Dawkins former wives and mother of his daughter apparently is or has become a fundamentalist Christian, and there has been vocal and published public disagreement on the issue, which probably feeds this attitude, but it’s nonetheless distracting from the message.
Regarding the question of the o.p., no, genes to not meet even the minimal categorical requirements for life; they do not independently consume, excrete, or reproduce anything, and are almost entirely dependent upon proteins to manipulate and produce them. The proteins, of course, are coded by the genome, which would seem to lead to a chicken and egg question–if you need proteins to build genes, and genes to code for the proteins, who did what to whom?–and this is certainly an active area of research into early evolution and abiogenesis for which we don’t have any concrete answers, but there are many qualified speculations on the precursors to genes and how autocatalyzing proteins could have morphed into creating nucleic acids. Life as we could recognize it very likely predates DNA, albeit only in a very simple fashion.
On pg. 22 (as I found the pages numbered in the Amazon.comsearch inside this book feature)
On pg. 34
On pg. 35
Thanks for all the responses! I especially appreciate the book references.
While I also appreciate the caveats in reading Dawkins I might easily have posted the same comments myself had someone else started a similar thread.
What puzzles me, aside from the issue of whether or not our genes are alive, is that he spends quite a few paragraphs explaining himself on topics as pedestrian as comparing a computer to a brain and what selfish or altruistic mean, and yet mentions nothing about making the assumption that genes are alive.
I suspect that he is using what he might call a language of convenience (pg 47, pg 66 and in the footnotes section in which he responds to Stranger’s professional idiot. ), but I have to wonder.
Emphasis Mine
They make copies of themselves. Every time a new cell is made: a blood cell, a skin cell, a muscle cell; the genes are copied for that cell. That takes some form of raw material. The genes themselves don’t make those materials, but neither do animals. Animals have to find and consume those materials to stay alive, unless another animal does it for them.
I have to agree though, that I don’t think they are alive, but J Cubed’s comment that they are like viruses makes me equivocate somewhat. I tend to think of viruses as being alive even if it is hard to say just how alive they are.
I would second Stranger on a Train’s excellent suggestion about reading Mayr (and possibly others as well, Gould too…) in addition to Dawkins. Dawkins is certainly highly intelligent and articulate, but also highly opinionated.
Also a little in his defense, I often use “live” to refer to where things are/should be kept, even if they’re not alive. E.g. “the chroroform lives in the flammables cabinet” or “the toothpicks live in the third drawer from the top” are not uncommon phrases in my life.
This isn’t really a very good analogy. Of course any organism or process requires raw materials that have to be scavenged from the environement in some form (hence, “consume” is one of the necessary prerequisites for life) but in the case of DNA raw materials are insufficient; DNA replication also requires the functioning of DNA polymerase, enzymes that catalyzes and controls the process of strand seperation and replication. It also requires a number of other enzymes and other proteins which regulate processes, break down nutrients into useable basic nucleotides, and provide energy. (In more complex cells, there are special organelles called mitochondria and chloroplasts, derived from independent cells which have sacrified autonomy to become codependent with the cell but still regain a small amount of unique, non-nuclear genetic material.) Although an unwound strand of DNA has some very limited catalytic capabilities, it is not capable of autocatalysis and requires significant outside aid to reproduce.
It’s almost universally agreed by molecular biologists that viruses are not alive by any reasonable definition of the term. Viruses can be classified in species, and some even come with their own RNA polymerase, but they still require hijacking the functionality of a archaea, bacteria, or eukaryota in order to replicate; otherwise, they’re just a strand of essentially inert RNA with a protein backbone or coat that will only break down by simple nonbiological processes.
I like Gould and think that he was an excellent, careful, and engaging writer, but his take on some concepts was out in left field. He’s great on historical issues, and provides a lot of balance (his explanation and defense of Lamarakism, in its day, is an excellent read and gives perspective on why that patently absurd philosophy was so reasonable given what was known at the time) but Mayr is technically more astute and rides well in the middle ground of evolutionary biology.
That’s a rather strong statement. All organisms depend on each other for survival, either by consuming each other, their by products, or by being in “ecolibrium” with an environment that wouldn’t exist without modification by other organisms. And viruses aren’t the only parasite. The fact that there is somewhat of a consensus among virologists to call them non living is about as meaningful as the current consensus among astronomers that Pluto isn’t a planet. Viruses are argued not to be ‘alive’ because they are not in cells and don’t respond to the environment. But they certainly have many “life-like” traits and being made of cells is just an arbitrary definition of life. Other phenomena not made of cells exhibit some life like qualities such as crystals, fire, and certain computer programs. We could certainly imagine aliens who seem very much alive but don’t happen to be made of cells.
For the sake of convenience, the cell is generally defined as the smallest unit of life, and therefore genes would not be considered “alive”. But this is a definition borne of semantic convenience. There’s no real distinct dividing line between “alive” and “not alive”.
No more left-field than, say, Dawkins, in my opinion. But Mayr is definitely the go-to guy for clear understanding of the Modern Synthesis (seeing as he helped spearhead the whole thing). Mayr’s academic output alone is nearly 10x that of Dawkins’! Sadly, Dawkins does have the advantage of still being alive, unlike both Gould and Mayr
(note that I had no real point to this post…just a lament)
Virus do not self-replicate, nor do they metabolize. They require subverting the machinery of the cells of archaea, bacteria, or eukaryota to consume, construct, and reproduce. Outside of these cells, they are essentially biologically inert; they can’t manufacture new proteins, or repair themselves, or break down nutrients into structural or nuclei proteins, et cetera. It’s not simply a matter that they have to prey on something else, but in fact, outside the boundaries of a cell, they don’t do anything. This is not the arbitrary distinction or semantic convenience as you analogize to the defintion of a planet; metabolism and self-replication are fundamental in the definition of life. We may be a little hazy in some examples as to what completely satisfies the conditions for life, but viruses clearly do not meet any standard for independent life.
I frankly don’t understand your point about crystals or fire having “life-like” traits; it is clear that these, too, are not alive in the sense of having and reproducing a complex structure which moderates energy flow to power its own processes and is robust in resisting alteration to structure. Viruses at least have a structure, and some even have a limited ability to catalyze the production of simple proteins, but none can reproduce their own structure in toto without hijacking the processes of a cellular organism.
I find it very difficult to conceive of an alien species that is not in some fashion built around a cellular organization. Even a simple species, analogous to archaebacteria, will require some kind of internal division of labor and processes in order to retain form and respond to environmental impulses in a way that utilizes the positive flow of energy from a high energy state to a low energy state to do work. A complex species–something equivilent to protists or more complex–has to have some kind of cellular organization to control growth and reproduction. Even a species not based on the reproduction of nucleotide macromolecules will almost certainly have some analogue to cellular organization; gestalt lava rock monsters and luminescent clouds of pure energy are all well and good for Star Trek, but in the real world, any complex self-organizing system implicitly has a cellular structure.
Regarding Dawkins, it’s definitely true that the extent to which he takes gene centricism is near the boundary, if not at the bleeding edge, of accepted theory. However, as time and understanding have moved on, the consensus has shifted more toward a broad acceptance of “selfish genes” (even if some of Dawkins’ specific arguments remain poorly founded or unsubstantiated), while many of Gould’s claims, specifically regarding many of his arguements for the hypothesis of punctuated equilibrium–much of which lacks a rigorous, quantifiable basis–have been abandoned or at least retreated from by the consensus. In fact, to read his detractors he frequently presented ideas that were already disproven or obsolete; I think this is a somewhat unfair criticism, as Gould was not lacking in understanding, but it followed more as a result of clinging to multi-level selection whereas Dawkins and the gene centric crowd did and does continue to focus on reductionism to a basal unit.
I think his most patently absurd claim is in regard to memes, which he views as not just being a metaphorical information theory “cousin” to genes, but an actual “conceptual genome” which creates an identical physical structure in the brain of anyone who encounters it. This notion lacks any basis in fact and is ascientific at best. He also does some business with a more complicated version of Conway’s life and insect-like constructs that result from an arbitrary computer algorithm (which he relates in The Blind Watchmaker) which is nothing but garbage. He definitely has his blind spots and opinions that are outside the norm.
While I personally favor the reductionist approach (with regard to sexually reproducing species, anyway…it becomes substantially more problematic with asexual species) and I think that advances in molecular biology and computational modeling of evolutionary strategies have demonstrated the validity of this general approach, the complex interplay of sophisticated organisms makes it difficult to apply this in general form in a way analogous to using quantum mechanics to predict the flight of a baseball. Enrst Mayr famously decried molecular biology and computational modeling approaches to evolution in a manner reminiscent of the way biologists of the first half of the 20th century and before claimed that basic physics could never explain the workings of biochemistry and living organisms, and Gould, though less virulent on the topic, seemed to advance a similar view.
I think this is wrong on a basic level, but in practice the statistical approach of modern evolutionary synthesis gives an adequate result without getting bogged down in the tedious complexities of how genes actually work. Since we’ve only very recently been able to fully map genomes and start to track the effects of individual genes, this has at least historically been an eminently reasonable position, and ironically, as greater understanding of the function of various parts of the genome has advanced, modern synthesis gave birth to reductionism and ultimately gene centricism. So, whatever your view is, Mayr is a good starting or grounding point from which much of modern evolutionary biology has, in one way or another, sprung forth.
To which, I can only say “meh”. I feel Gould & Eldredge were right about PuncEq (it should be noted that though Gould was the mouthpiece for PE, Eldredge did most of the legwork in formulating the theory; Gould has admitted as much), as well as multi-level selection (except for group selection…) and Dawkins and Co. about 95% wrong regarding genic selection (I believe it does occur, but is not, by a long shot, the “preferred” focus of selection. And, again, Dawkins is largely the primary mouthpiece, but not the original formulator). Personally, I’m a Darwinian in philosophy: individual organisms are the primary focus of selection, and selection only “sees” phenotypes for the most part (again, I am of the opinion that there are instances wherein individual genes can be selected directly, and there are cases in which populations, or in extreme cases entire species, can be the object of selection).
Though I agree 100% with your assessment of “memes”.
None of which is relevant to this thread, of course, but I haven’t posted much lately, and I’m bored
I found some comments of Dawkins’ from earlier in the book that caught my attention. In the hopes of making my point quickly, I have used some editing of convenience. However, Dawkins does make a similar connection on pg. 18 of my copy of the book.
Completely ignoring the concept of what replicators are…
My point is primarily that Dawkins does address the issue to some extent.
Also, I think I understand more clearly that the point of the first few chapters of the book is to highlight the idea that the gene is the unit of natural selection.
When I finish this book, and the pile on top of the television, I’ll grapple with some of those suggested here.
I don’t have handy my copies of The Selfish Gene and The Extended Phenotype to cite from, but I’m pretty confident that even Dawkins doesn’t argue that the focus of selection are genes (except in very special instances where the physical form of the genome is directly acted upon by some enzyme or phage), but rather that the gene is inarguably the physical unit of inheritance. Selection, in his view (and the view of most gene centric theorists) acts upon the phenotypical expression of genes, singly or in combination, and that a sufficiently broad definition of phenotype can encompass all higher order categories, from individual functional units of a cell, organ, organism, kin, or group, and by adopting this approach it is, at least in theory, possible to reduce selection upon phenotypical attributes at all levels to their effect on the genome. From the bottom up view, this means that the individual gene “competes” with other genes to be successfully expressed in some form that benefits the carrier and leads to propagation of the gene. Thus, there’s nothing non-Darwinian about it; it just applies an underlying mechanic to the traditional Darwinian approach of viewing competition between organisms or higher groups.
Now, I have to admit a strong personal preference for the gene-centric view as the fundamental level on which the mechanics of competition occur or can be applied. My background is in engineering and physics, and while it is acceptable in those disciplines to model a behavior by approximate methods, the desire is to understand the fundamental mechanic. Even though we can’t analytically model turbulent flows in closed form and model them as being approximately fluid continuums with the Navier-Stokes equations or other methods of statistical mechanics, we know that the underlying mechanic occurs at the molecular and atomic level, and at least in theory you could develop a quantum electrodynamic description of the model (albeit one that strictly speaking would only give you answers in terms of probability), although in practice this would be incalculably complex for any real world event. I’d like to think the same about evolutionary biology and the mechanics of natural selection; that rather than occuring as distinct processes on different and somewhat arbitrary levels, that there is a single set of underlying principles at the root level of inheritance upon which selection fundamentally acts.
Talking about kin selection, group selection, organism selection, and so forth as if they are distinct processes that are disconnected (which is, perhaps incorrectly, the impression I get from many texts) strikes me as handwaving, a denial that there is a more fundamental and quantifiable process which dictates how these observable processes occur. Mayr was famous for decrying mathematical approaches, and although I can’t cite it offhand I recall once reading of him railing against molecular biology as being useless in terms of making any headway in understanding natural selection, which struck me as being nothing but pig-headed. This was, I believe, in the early days of molecular biology, when the field started to become populated by scientists from other, more mathematically-oriented disciplines like physics, and I suspect this came out of a sense of propriety and provincialism, but that kind of thinking leaves me somewhat suspect of the basis behind arguing for higher order selection as fundamental or discrete levels.
Punctuated equilibrium strikes me less as a well-defined hypothesis than a series of interpretations. Even from the writings of Eldredge and Gould I’m not entirely clear on what they believe to be the fundamental cause; at least in the case of Gould, he suggested a number of different causes that were at least somewhat at odds with one another. Note that Dawkins (and presumably some other) gene centricists don’t argue that PE did not happen (though they may object to the label and the connotations that come along with it), but rather than the theories advanced for PE are either insufficiently composed, overly complex, or implicitly teleological in nature. Certainly there were “explosions” of the variety of species in certain phylums in the fossil record (and that these are not just artifacts of incompleteness of the record) but the reasons for thus are not entirely clear, though arguments for accelerated or high-level mutation and saltation divorced from the ordinary and accepted mechanism of natural selection strike me as being arbitrary and without basis. I think that there have been and remain a wide range of misstatements and misinterpretations of PE which has contributed to the overall confusion about the concept. Certainly many pop-lit critics, like Daniel Dennett, have almost completely misunderstood the term and concepts behind it, and their critiques are more obtuse than even the most extended advocates.
Regarding gene centric theory, Dawkins was not the first to develop it in current form (I’d say that George Williams deserves that credit), and his work is clearly derived from Haldane, Fisher, and Wright, he’s functioned as more than just a mouthpiece for the concept, including a significant contribution into the notion of the effect of genes and resultant impact upon selection beyond the physical boundaries of the carrier, the so-called extended phenotype. This generalization of the concept of phenotypical expression allows gene seleciton to be applied beyond the number of fingers and toes one has and directly into why a certain gene is preferred and why it propagates. However, I think Crick’s central principle of molecular biology–that all information flows from the nucleic acid to protein–is what persuades me that the fundamental level upon which selection should be concerned with is the gene, even though selective pressures act upon the carrier.
Yeah, this one is total doo-doo on Dawkins part, and I’m not certain why he has and does continue to promote it. The popular concept of a meme–an idea which has some implicitly preferred cognitive pathway–is just barely plausible; one can speak, for instance, of rhymes or musical cues as being catchy regardless of background, although the fact that physical brain development and resultant cognitative processes are significantly modified in development and by environment tends to weaken even that claim. But Dawkins’ more concrete notion that these supposed memes create an identifiable, unique, and reproducible physical structure within the brains of those exposed to it is beyond all belief, and totally unsupported by any evidence in neurology and cognitive science. It’s not just speculative; it is, IMHO, totally unfounded and as wacky as Fred Hoyle and his claim that are noses turn down so we don’t absorb space-borne viruses. Everybody has a blind spot or a few in rationality, I guess, and this is clearly one of Dawkins’.
Eh, the o.p.'s question as been asked and answered, and answered again, and plus it’s an interesting topic with no clear-cut or universally accepted answer, so like Jack Burton always says, what the hell. Besides, I keep meaning to read up on Crick’s work in neuroscience and the neurophysical basis for consciousness and this reminded me. Now I just have to figure out how to get access to the Milliken Library again since the company cut off our corporate subscription.
), but I have to wonder.
