The above article is a critique Dawkins view of The Selfish Gene and The Extended Phenotype. I agree with his criticism of Dawkins, but not his position of how evolution takes place, which is through Natural Selection based on ecology, not genes.
Shortly after I began to post on BioLogos I brought up the concept of Niche Construction theory which I researched for my book.
I was informed by others on the web site that Richard Dawkins and friends had refuted this view. after some digging on the web I found that some supporters of Dawkins in Europe called a conference to denounce Niche Construction as counter to Dawkins’ view of the Extended Phenotype, which they did.
Dawkins magnanimously said that it was not wrong, but might be considered as an aspect of the Extended Phenotype, which explains how genes control behavior. .
I think that I sent you a copy of my book and if so look on pp. 51-52 of Darwin’s Myth.
The only difference is that “fitter” is the word with a technical definition in the models we use. (Actually, in my neck of the woods at least, we usually use the selection coefficient, s, rather than the fitness (fitness = 1 + s)).
Many commentators on this forum have rued the relative lack of mathematics in biological theories, compared to the theories of other sciences. My feeling is that if biologists can define fitness mathematically in the context of a math-based model, I’m all for it. In fact, I’d readily give up 100 photos of long-necked giraffes and whale fins and whatnot for one good set of equations. And it seems that biologists agree with that approach.
Sure there is: “however slight this may be”. It’s a crude quantification, but it’s still quantification. In any case, so what? The definition of fitness changed by including probability, not by being quantified. Darwinians had no problem with quantifying fitness.
Right. It’s almost as if the particular word doesn’t matter at all.
It’s not clear to me that any communication is occurring in this thread. Let me start again from the beginning.
Darwin had the notion that some traits made an organism more suited to its environment – that they made it more fitted for it – and that this suitability would make it more successful reproductively. White bunnies really are more suitable for life on the tundra than brown bunnies. That notion has not changed. Morgan had the same notion, and so do I. That’s why we continue to use Darwin’s term today.
What’s been subject to change is the precise definition of fitness. As long as you’re thinking about large populations, and (more importantly) that you’re thinking about variation as a cloud of infinitesimal changes always accessible to the population, then it’s fine to collapse the two parts of the notion and just define “fittest” as “having the most offspring”, because natural selection is always operating. That worked for Darwin and for the architects of the Modern Synthesis, because that’s how they were thinking of variation.
Once you start dealing with small populations, though, and the reality that variation occurs as discrete mutations and that some of these will be absent or rare, then you have a problem. You have to deal with the fact that mutation, survival and reproduction are all stochastic processes. This means that the definition of fitness no longer matches the core notion, because sometimes the more suitable organism doesn’t survive. Sometimes the white bunny gets eaten by the tundra cats sooner than the brown bunny. You can keep the definition – whatever survives is more fit – if you insist, but you’ll lose the core idea of natural selection and adaptation. Brown bunnies really aren’t better adapted to life on the tundra. If you do that, you’ve now got a concept of fitness that has no obvious utility for anything.
Alternatively, you can recognize that the original notion didn’t depend on the precise definition, and is in fact captured better by a slight tweak to that definition: what is best suited to the environment is the type that tends to leave the most offspring. That way fitness is still directly connected to Darwin’s insight about natural selection and adaptation, we have a definition we can use in mathematical models, we’ve extended the Modern Synthesis, and everyone is happy. Everyone except you, that is, for reasons that I do not at all understand.
It’s precisely because traits don’t map one-to-one to alleles that you have to consider the fitness of alleles, at least if you’re interested in the fate of individual mutations. A “trait” is an often arbitrary way to describe an aspect of an extremely complex organism, and different traits can overlap or be highly correlated; it may not be possible to have one trait without also having another. An allele, though, is a real thing, a real state of the individual’s DNA. The fitness of the allele represents the entire effect on reproductive fitness of any and all phenotypic changes that the allele causes.
Now, if you happen to be more interested at the moment in a trait than in molecular evolution, it’s also fine to talk about the fitness of the trait, however many alleles may have contributed to it. But sometimes all you know is that an allele has increased in frequency, without having a clue what traits are involved.
Either way, the fitness describes the expected reproductive success of one class of individuals compared to that of another.
I completely agree, at least for species like humans. If you look at my quoted words in context, you will see that I was explaining why Darwin and the modern synthesists didn’t consider stochastic effects in NS. To state it more precisely, in the situations they were thinking about, the actual reproductive success is never significantly different than the expected reproductive success, and thus they did not need to distinguish between the two. I was not suggesting that there is no difference between the two, or that the situations they were thinking about covered all real-world populations.
No, I admitted nothing of the sort. See my last paragraph. I wasn’t telling you how I think about fitness; I was explaining why Darwin and others didn’t fully work out the concept of fitness.
Quite true – provided there are enough of both color bunnies in the Arctic. In practice, we’re usually interested in traits or alleles that have proved to be more fit because they succeeded. That doesn’t mean we should be satisfied with a muddled concept of fitness, though. A muddled concept won’t help us when we are considering cases where expected reproductive success is very different from actual success. [quote=“Eddie, post:195, topic:5784”]
It’s only when we ask why white rabbits are more fit that theoretical reasoning about various traits and their advantages becomes important. But to me, it’s the latter questions that are far more interesting.
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They’re more interesting to lots of other people, too, including lots of biologists. That’s why one research program is to identify beneficial alleles and then figure out what traits they affect. That’s actually quite a hard problem, but there have been successes. Regardless, the fact that there are other questions to answer doesn’t mean we should think sloppily about fitness.
Great. Here is the portal for the complete 1000 Genomes data. Tell me which alleles out-reproduced others.
They’re more fit in the technical sense of the “fit” as well. Does this mean you’ve decided that the technical sense of “fit” isn’t so far from the common-sense meaning after all? (Also, if it’s so obvious as to be hardly mentioning, why did my mentioning it trigger this entire lengthy exchange?)
Some of the perils of modelling selection from purely genomic studies are mentioned here. No doubt the models are continually updated, but are always vulnerable to their theoretical assumprions.
The paper starts with a history lesson with THREE misconceptions about evolution (misconceptions that are often promoted by ID advocates) associated with neo-Darwinism. This of course totally validates my consistent claim that neo-Darwinism was falsified a long time ago, and is not synonymous with modern evolutionary theory. The article prefaces these misconceptions by saying:
As a result of these gaps in knowledge, certain unrealistic views became part and parcel of the Neo-Darwinist account of natural selection, and unfortunately, many of these are still with us, at least implicitly. The following are three major areas of misconception among the Neo-Darwinists:
Here is the point. All this stuff was fixed with neutral theory (which was addressed in the next section of the paper). Then the paper instead focuses on better ways to detect positive selection when it occurs. Remember, neutral theory does not deny the importance of positive selection, but correctly recognizes that is quantitatively less important than other non-Darwinian mechanisms.
So of course it is silly when ID people argue against neo-Darwinism as if that is the position of mainstream science. That is an absurd misrepresentation of our best understanding of evolution, and fundamentally misleading to the public. It is about as sensible as arguing against the “sufficiency” of Newtonian Physics as evidence for rejecting Einstein’s Relativity. The whole argument relies on a false equivalence between neo-Darwinism and the modern understanding of evolution. As the referenced paper makes exceedingly clear, these are not the same thing.
So if ID was arguing against neo-Darwinism to correctly teach the modern theory of evolution, that would be great and welcomed. Instead, they argue against neo-Darwinism (conflating it incorrectly with the modern understanding of evolution) as if this is evidence for design. That is simply bad logic, whether or not it is intentional or ignorant misrepresentation.
Nevertheless, Hughes complains that at the time of writing, “hundred” of papers were still being published in which the lessons of neutral theory have not been suffficiently learned, and hence the assumptions of the models used lead to badly skewed understandings of selection.
More critically, he criticises the practice of using any model that is not cross-checked against empirical data (once more suggesting that such methodological error is widely practised). He does, indeed, repeat the claim in his 2007 paper and (if memory serves) one three years later - clearly he felt the lessons were still not being learned even in 2010.
He doesn’t mention ID at all, and the context of my entire argument on this thread has not been about ID, but the limits of science with respect to contingency and complex systems, so it seems somewhat diversionary to turn Hughes’ strong critique of methodological errors within mainstream biology on to what ID people say. That wasn’t the point of the citation - nor even of Eddie’s comments on the thread.
That said, I accept the thread title is about Intelligent Design, so my whole argument about contingency is off-topic… but I think, more significant to EC than the tired old culture wars stuff.
Information Theory is a very technical topic that is not easy for people to apply correctly or assess. I am not going to litigate this in internet comments. I’m working on some academic papers to address these issues. I’ll let you know as they are published.
I agree here too. That is more important, and you are starting to clarify your thoughts there. Great. If you can find a way to express it that doesn’t seem to be disputing the details of NS, you will be onto something. I’ll point out also that Francis Collins has made comments supporting your notion (he explicitly references the KT event). So you are in good company.